The American Journal of Orthopedics

Editor’s Note: AJO is fortunate to have Shane Nho, one of the nation’s leading hip arthroscopists, as our Deputy Editor-in-Chief. He has compiled an outstanding update for all orthopedic surgeons who see hip patients. It’s my pleasure to turn this issue over to him. On a side note, we’ve added a new feature for our speed readers. From now on, all articles published in AJO will feature a “Take-Home Points” text box. These points represent the most important items that the authors wish to convey from their article. Please enjoy this month’s issue and keep the feedback coming. We are striving to continuously improve AJO and make it your go-to journal for practical information that you can apply directly to your practice.

—Bryan T. Hanypsiak, MD

Hip arthroscopy has been evolving over the past 2 decades as our techniques have been refined and our clinical outcomes have been reported. We have reached a point in our field to look back at the progress that has been made while also providing our readers with the most up-to-date information on diagnosis, imaging studies, and decision making for appropriate treatment.

Trofa and colleagues provide an excellent overview on intra- and extra-articular pathology of the hip and pelvis in their article, “Mastering the Physical Examination of the Athlete’s Hip”. The authors review common injuries in the athlete and provide physical examination tests to differentiate between adductor strain, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI). Also in this issue, Lewis and colleagues provide a comprehensive review of imaging studies in the “Imaging for Nonarthritic Hip Pathology”. The authors review the most common radiographic measurements to detect FAI as well as describe the role of computed tomography and magnetic resonance imaging.

The mastery of hip arthroscopy for the treatment of FAI has a steep learning curve and the techniques have evolved along with our understanding of the importance of the labrum and capsule. We are fortunate to have an article provided by one of the pioneers in the field, Dr. Marc J. Philippon, describing his role in advancing the field in the article “Treatment of FAI: Labrum, Cartilage, Osseous Deformity, and Capsule”. Kollmorgen and Mather provide the most up-to-date techniques for labrum repair and reconstruction. Friel and colleagues report on capsular repair and plication using the T-capsulotomy and the extensile interportal capsulotomy.

We also have the opportunity to read about a number of clinical studies describing the experiences of multi-center studies and epidemiologic studies on large volumes of data. The ANCHOR group provides a summary of the experiences of some of the most renowned hip surgeons in North America as the treatment of FAI evolved from an open approach to an all-arthroscopic approach. The MASH group is a large multi-center group of hip arthroscopists in the United States who describe their current indications for surgical treatment of FAI.

On AmJOrthopedics.com, Matsuda and colleagues describe the outcomes of borderline dysplasia patients compared to normal controls across multiple centers. Anthony and colleagues report on the complication rates using the National Surgical Quality Improvement Program database.

I believe that our Hip Arthroscopy issue will not disappoint you. It is a comprehensive review of the state-of-the-art in hip arthroscopy from physical examination to current surgical techniques to clinical outcomes from large databases for the treatment of FAI. After reviewing this issue, you will be equipped with the most up-to-date information on the treatment of nonarthritic hip disease.

Am J Orthop. 2017;46(1):8. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Editor’s Note: AJO is fortunate to have Shane Nho, one of the nation’s leading hip arthroscopists, as our Deputy Editor-in-Chief. He has compiled an outstanding update for all orthopedic surgeons who see hip patients. It’s my pleasure to turn this issue over to him. On a side note, we’ve added a new feature for our speed readers. From now on, all articles published in AJO will feature a “Take-Home Points” text box. These points represent the most important items that the authors wish to convey from their article. Please enjoy this month’s issue and keep the feedback coming. We are striving to continuously improve AJO and make it your go-to journal for practical information that you can apply directly to your practice.

—Bryan T. Hanypsiak, MD

Hip arthroscopy has been evolving over the past 2 decades as our techniques have been refined and our clinical outcomes have been reported. We have reached a point in our field to look back at the progress that has been made while also providing our readers with the most up-to-date information on diagnosis, imaging studies, and decision making for appropriate treatment.

Trofa and colleagues provide an excellent overview on intra- and extra-articular pathology of the hip and pelvis in their article, “Mastering the Physical Examination of the Athlete’s Hip”. The authors review common injuries in the athlete and provide physical examination tests to differentiate between adductor strain, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI). Also in this issue, Lewis and colleagues provide a comprehensive review of imaging studies in the “Imaging for Nonarthritic Hip Pathology”. The authors review the most common radiographic measurements to detect FAI as well as describe the role of computed tomography and magnetic resonance imaging.

The mastery of hip arthroscopy for the treatment of FAI has a steep learning curve and the techniques have evolved along with our understanding of the importance of the labrum and capsule. We are fortunate to have an article provided by one of the pioneers in the field, Dr. Marc J. Philippon, describing his role in advancing the field in the article “Treatment of FAI: Labrum, Cartilage, Osseous Deformity, and Capsule”. Kollmorgen and Mather provide the most up-to-date techniques for labrum repair and reconstruction. Friel and colleagues report on capsular repair and plication using the T-capsulotomy and the extensile interportal capsulotomy.

We also have the opportunity to read about a number of clinical studies describing the experiences of multi-center studies and epidemiologic studies on large volumes of data. The ANCHOR group provides a summary of the experiences of some of the most renowned hip surgeons in North America as the treatment of FAI evolved from an open approach to an all-arthroscopic approach. The MASH group is a large multi-center group of hip arthroscopists in the United States who describe their current indications for surgical treatment of FAI.

On AmJOrthopedics.com, Matsuda and colleagues describe the outcomes of borderline dysplasia patients compared to normal controls across multiple centers. Anthony and colleagues report on the complication rates using the National Surgical Quality Improvement Program database.

I believe that our Hip Arthroscopy issue will not disappoint you. It is a comprehensive review of the state-of-the-art in hip arthroscopy from physical examination to current surgical techniques to clinical outcomes from large databases for the treatment of FAI. After reviewing this issue, you will be equipped with the most up-to-date information on the treatment of nonarthritic hip disease.

Am J Orthop. 2017;46(1):8. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Editor’s Note: AJO is fortunate to have Shane Nho, one of the nation’s leading hip arthroscopists, as our Deputy Editor-in-Chief. He has compiled an outstanding update for all orthopedic surgeons who see hip patients. It’s my pleasure to turn this issue over to him. On a side note, we’ve added a new feature for our speed readers. From now on, all articles published in AJO will feature a “Take-Home Points” text box. These points represent the most important items that the authors wish to convey from their article. Please enjoy this month’s issue and keep the feedback coming. We are striving to continuously improve AJO and make it your go-to journal for practical information that you can apply directly to your practice.

—Bryan T. Hanypsiak, MD

Hip arthroscopy has been evolving over the past 2 decades as our techniques have been refined and our clinical outcomes have been reported. We have reached a point in our field to look back at the progress that has been made while also providing our readers with the most up-to-date information on diagnosis, imaging studies, and decision making for appropriate treatment.

Trofa and colleagues provide an excellent overview on intra- and extra-articular pathology of the hip and pelvis in their article, “Mastering the Physical Examination of the Athlete’s Hip”. The authors review common injuries in the athlete and provide physical examination tests to differentiate between adductor strain, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI). Also in this issue, Lewis and colleagues provide a comprehensive review of imaging studies in the “Imaging for Nonarthritic Hip Pathology”. The authors review the most common radiographic measurements to detect FAI as well as describe the role of computed tomography and magnetic resonance imaging.

The mastery of hip arthroscopy for the treatment of FAI has a steep learning curve and the techniques have evolved along with our understanding of the importance of the labrum and capsule. We are fortunate to have an article provided by one of the pioneers in the field, Dr. Marc J. Philippon, describing his role in advancing the field in the article “Treatment of FAI: Labrum, Cartilage, Osseous Deformity, and Capsule”. Kollmorgen and Mather provide the most up-to-date techniques for labrum repair and reconstruction. Friel and colleagues report on capsular repair and plication using the T-capsulotomy and the extensile interportal capsulotomy.

We also have the opportunity to read about a number of clinical studies describing the experiences of multi-center studies and epidemiologic studies on large volumes of data. The ANCHOR group provides a summary of the experiences of some of the most renowned hip surgeons in North America as the treatment of FAI evolved from an open approach to an all-arthroscopic approach. The MASH group is a large multi-center group of hip arthroscopists in the United States who describe their current indications for surgical treatment of FAI.

On AmJOrthopedics.com, Matsuda and colleagues describe the outcomes of borderline dysplasia patients compared to normal controls across multiple centers. Anthony and colleagues report on the complication rates using the National Surgical Quality Improvement Program database.

I believe that our Hip Arthroscopy issue will not disappoint you. It is a comprehensive review of the state-of-the-art in hip arthroscopy from physical examination to current surgical techniques to clinical outcomes from large databases for the treatment of FAI. After reviewing this issue, you will be equipped with the most up-to-date information on the treatment of nonarthritic hip disease.

Am J Orthop. 2017;46(1):8. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Perform a comprehensive examination to determine intra-articular pathology as well as potential extra-articular sources of hip and pelvic pain.
• Adductor strains can be prevented with adequate rehabilitation focused on correcting predisposing factors (ie, adductor weakness or tightness, limited range of motion, and core imbalance).
• Athletic pubalgia is diagnosed when tenderness can be elicited over the pubic tubercle.
• Osteitis pubis is diagnosed with pain over the pubic symphysis.
• FAI and labral injury classically present with a C-sign but can also present with lateral hip pain, buttock pain, low back pain, anterior thigh pain, and knee pain.

Hip and groin pain is a common finding among athletes of all ages and activity levels. Such pain most often occurs among athletes in sports such as football, hockey, rugby, soccer, and ballet, which demand frequent cutting, pivoting, and acceleration.^1-4 Previously, pain about the hip and groin was attributed to muscular strains and soft-tissue contusions, but improvements in physical examination skills, imaging modalities, and disease-specific treatment options have led to increased recognition of hip injuries as a significant source of disability in the athletic population.^5,6 These injuries make up 6% or more of all sports injuries, and the rate is increasing.^7-9

In this review, we describe precise methods for evaluating the athlete’s hip or groin with an emphasis on recognizing the most common extra-articular and intra-articular pathologies, including adductor strains, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI) with labral tears.

Hip Pathoanatomy

The first step in determining the etiology of pain is to establish if there is true pathology of the hip joint and surrounding structures, or if the pain is referred from another source.

Patient History

The physical examination is guided by the patient’s history. Important patient-specific factors to be ascertained include age, sport(s) played, competition level, seasonal timing, and effect of the injury on performance. Regarding presenting symptoms, attention should be given to pain location, timing (acute vs chronic), onset, nature (clicking, catching, instability), and precipitating factors. Acute-onset pain with muscle contraction or stretching, possibly accompanied by an audible pop, is likely musculotendinous in origin. Insidious-onset dull aching pain that worsens with activity more commonly involves intra-articular processes. Most classically, this pain occurs deep in the groin and is demonstrated by the C sign: The patient cups a hand with its fingers pointing toward the anterior groin at the level of the greater trochanter (Figure 1).¹¹

A comprehensive hip evaluation can be performed with the patient in the standing, seated, supine, lateral, and prone positions, as previously described (Table 2).^6,12,13

Extra-Articular Hip Pathologies

Adductor Strains

The adductor muscle group includes the adductor magnus, adductor brevis, gracilis, obturator externus, pectineus, and adductor longus, which is the most commonly strained. Adductor strains are the most common cause of groin pain in athletes, and usually occur in sports that require forceful eccentric contraction of the adductors.¹⁴ Among professional soccer players, adductor strains represent almost one fourth of all muscle injuries and result in lost playing time averaging 2 weeks and an 18% reinjury rate.¹⁵ These injuries are particularly detrimental to performance because the adductor muscles help stabilize the pelvis during closed-chain activities.³ Diagnosis and adequate rehabilitation focused on correcting predisposing factors (eg, adductor weakness or tightness, loss of hip range of motion, core imbalance) are paramount in reinjury prevention.^16,17

On presentation, athletes complain of aching groin or medial thigh pain. The examiner should assess for swelling or ecchymosis. There typically is tenderness to palpation at or near the origin on the pubic bones, with pain exacerbated with resisted adduction and passive stretch into abduction during examination. Palpation of adductors requires proper exposure and is most easily performed with the patient supine and the lower extremity in a figure-of-4 position (Figure 2A).

Athletic Pubalgia

Athletic pubalgia, also known as sports hernia or core muscle injury, is an injury to the soft tissues of the lower abdominal or posterior inguinal wall. Although not fully understood, the condition is considered the result of repetitive trunk hyperextension and thigh hyperabduction resulting in shearing at the pubic symphysis where there is a muscle imbalance between the strong proximal thigh muscles and weaker abdominals. This condition is more common in men and typically is insidious in onset with a prolonged course recalcitrant to nonoperative treatment.¹⁸ In studies of chronic groin pain in athletes, the rate of athletic pubalgia as the primary etiology ranges from 39% to 85%.^9,19,20

Patients typically complain of increasing pain in the lower abdominal and proximal adductors during activity. Symptoms include unilateral or bilateral lower abdominal pain, which can radiate toward the perineum, rectus muscle, and proximal adductors during sport but usually abates with rest.¹⁸ Athletes endorse they are not capable of playing at their full athletic potential. Symptoms are initiated with sudden forceful movements, as in sit-ups, sprints, and valsalva maneuvers like coughs and sneezes. Valsalva maneuvers worsen pain in about 10% of patients.^21-23On physical examination with the patient supine, tenderness can be elicited over the pubic tubercle, abdominal obliques, and/or rectus abdominis insertion (Figure 3A). Athletes may also have tenderness at the adductor longus tendon origin at or near the pubic symphysis, which may make the diagnosis difficult to distinguish from an adductor strain.

Osteitis Pubis

Osteitis pubis is a painful overuse injury that results in noninfectious inflammation of the pubic symphysis from increased motion at this normally stable immobile joint.³ As with athletic pubalgia, the exact mechanism is unclear, but likely it is similar to the repetitive stress placed on the pubic symphysis by unequal forces of the abdominal and adductor muscles.²⁴ The disease can result in bony erosions and cartilage breakdown with irregularity of the pubic symphysis.

Athletes may complain of anterior and medial groin pain that can radiate to the lower abdominal muscles, perineum, inguinal region, and medial thigh. Walking, pelvic motion, adductor stretching, abdominal muscle exercises, and standing up can exacerbate pain.²⁴ Some cases involve impaired internal or external rotation of the hip, sacroiliac joint dysfunction, or adductor and abductor muscle weakness.²⁵The distinguishing feature of osteitis pubis is pain over the pubic symphysis with direct palpation (Figure 4A). Examination maneuvers that place stress on the pubic symphysis can aid in diagnosis.²⁶

Intra-Articular Hip Pathology: Femoroacetabular Impingement

In athletes, FAI is a leading cause of intra-articular pathology, which can lead to labral tears.^28,29 FAI lesions include cam-type impingement from an aspherical femoral head and pincer impingement from acetabular overcoverage, both of which limit internal rotation and cause acetabular rim abutment, which damages the labrum.

Athletes present with activity-related groin or hip pain that is exacerbated by hip flexion and internal rotation, with possible mechanical symptoms from labral tearing.³⁰ However, the pain distribution varies. In a study by Clohisy and colleagues,³¹ of patients with symptomatic FAI that required surgical intervention, 88% had groin pain, 67% had lateral hip pain, 35% had anterior thigh pain, 29% had buttock pain, 27% had knee pain, and 23% had low back pain.

Careful attention should be given to range of motion in FAI patients, as they can usually flex their hip to 90° to 110°, and in this position there is limited internal rotation and asymmetric external rotation relative to the contralateral leg.³² The anterior impingement test is one of the most reliable tests for FAI (Figure 5A).³² With the patient supine, the hip is dynamically flexed to 90°, adducted, and internally rotated. A positive test elicits deep anterior groin pain that generally replicates the patient’s symptoms.²⁹

Conclusion

Careful, directed history taking and physical examination are essential in narrowing the diagnostic possibilities before initiating a workup for the common intra-articular and extra-articular causes of hip and groin pain in athletes.

Take-Home Points

• Perform a comprehensive examination to determine intra-articular pathology as well as potential extra-articular sources of hip and pelvic pain.
• Adductor strains can be prevented with adequate rehabilitation focused on correcting predisposing factors (ie, adductor weakness or tightness, limited range of motion, and core imbalance).
• Athletic pubalgia is diagnosed when tenderness can be elicited over the pubic tubercle.
• Osteitis pubis is diagnosed with pain over the pubic symphysis.
• FAI and labral injury classically present with a C-sign but can also present with lateral hip pain, buttock pain, low back pain, anterior thigh pain, and knee pain.

Hip and groin pain is a common finding among athletes of all ages and activity levels. Such pain most often occurs among athletes in sports such as football, hockey, rugby, soccer, and ballet, which demand frequent cutting, pivoting, and acceleration.^1-4 Previously, pain about the hip and groin was attributed to muscular strains and soft-tissue contusions, but improvements in physical examination skills, imaging modalities, and disease-specific treatment options have led to increased recognition of hip injuries as a significant source of disability in the athletic population.^5,6 These injuries make up 6% or more of all sports injuries, and the rate is increasing.^7-9

In this review, we describe precise methods for evaluating the athlete’s hip or groin with an emphasis on recognizing the most common extra-articular and intra-articular pathologies, including adductor strains, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI) with labral tears.

Hip Pathoanatomy

The first step in determining the etiology of pain is to establish if there is true pathology of the hip joint and surrounding structures, or if the pain is referred from another source.

Patient History

The physical examination is guided by the patient’s history. Important patient-specific factors to be ascertained include age, sport(s) played, competition level, seasonal timing, and effect of the injury on performance. Regarding presenting symptoms, attention should be given to pain location, timing (acute vs chronic), onset, nature (clicking, catching, instability), and precipitating factors. Acute-onset pain with muscle contraction or stretching, possibly accompanied by an audible pop, is likely musculotendinous in origin. Insidious-onset dull aching pain that worsens with activity more commonly involves intra-articular processes. Most classically, this pain occurs deep in the groin and is demonstrated by the C sign: The patient cups a hand with its fingers pointing toward the anterior groin at the level of the greater trochanter (Figure 1).¹¹

A comprehensive hip evaluation can be performed with the patient in the standing, seated, supine, lateral, and prone positions, as previously described (Table 2).^6,12,13

Extra-Articular Hip Pathologies

Adductor Strains

The adductor muscle group includes the adductor magnus, adductor brevis, gracilis, obturator externus, pectineus, and adductor longus, which is the most commonly strained. Adductor strains are the most common cause of groin pain in athletes, and usually occur in sports that require forceful eccentric contraction of the adductors.¹⁴ Among professional soccer players, adductor strains represent almost one fourth of all muscle injuries and result in lost playing time averaging 2 weeks and an 18% reinjury rate.¹⁵ These injuries are particularly detrimental to performance because the adductor muscles help stabilize the pelvis during closed-chain activities.³ Diagnosis and adequate rehabilitation focused on correcting predisposing factors (eg, adductor weakness or tightness, loss of hip range of motion, core imbalance) are paramount in reinjury prevention.^16,17

On presentation, athletes complain of aching groin or medial thigh pain. The examiner should assess for swelling or ecchymosis. There typically is tenderness to palpation at or near the origin on the pubic bones, with pain exacerbated with resisted adduction and passive stretch into abduction during examination. Palpation of adductors requires proper exposure and is most easily performed with the patient supine and the lower extremity in a figure-of-4 position (Figure 2A).

Athletic Pubalgia

Athletic pubalgia, also known as sports hernia or core muscle injury, is an injury to the soft tissues of the lower abdominal or posterior inguinal wall. Although not fully understood, the condition is considered the result of repetitive trunk hyperextension and thigh hyperabduction resulting in shearing at the pubic symphysis where there is a muscle imbalance between the strong proximal thigh muscles and weaker abdominals. This condition is more common in men and typically is insidious in onset with a prolonged course recalcitrant to nonoperative treatment.¹⁸ In studies of chronic groin pain in athletes, the rate of athletic pubalgia as the primary etiology ranges from 39% to 85%.^9,19,20

Patients typically complain of increasing pain in the lower abdominal and proximal adductors during activity. Symptoms include unilateral or bilateral lower abdominal pain, which can radiate toward the perineum, rectus muscle, and proximal adductors during sport but usually abates with rest.¹⁸ Athletes endorse they are not capable of playing at their full athletic potential. Symptoms are initiated with sudden forceful movements, as in sit-ups, sprints, and valsalva maneuvers like coughs and sneezes. Valsalva maneuvers worsen pain in about 10% of patients.^21-23On physical examination with the patient supine, tenderness can be elicited over the pubic tubercle, abdominal obliques, and/or rectus abdominis insertion (Figure 3A). Athletes may also have tenderness at the adductor longus tendon origin at or near the pubic symphysis, which may make the diagnosis difficult to distinguish from an adductor strain.

Osteitis Pubis

Osteitis pubis is a painful overuse injury that results in noninfectious inflammation of the pubic symphysis from increased motion at this normally stable immobile joint.³ As with athletic pubalgia, the exact mechanism is unclear, but likely it is similar to the repetitive stress placed on the pubic symphysis by unequal forces of the abdominal and adductor muscles.²⁴ The disease can result in bony erosions and cartilage breakdown with irregularity of the pubic symphysis.

Athletes may complain of anterior and medial groin pain that can radiate to the lower abdominal muscles, perineum, inguinal region, and medial thigh. Walking, pelvic motion, adductor stretching, abdominal muscle exercises, and standing up can exacerbate pain.²⁴ Some cases involve impaired internal or external rotation of the hip, sacroiliac joint dysfunction, or adductor and abductor muscle weakness.²⁵The distinguishing feature of osteitis pubis is pain over the pubic symphysis with direct palpation (Figure 4A). Examination maneuvers that place stress on the pubic symphysis can aid in diagnosis.²⁶

Intra-Articular Hip Pathology: Femoroacetabular Impingement

In athletes, FAI is a leading cause of intra-articular pathology, which can lead to labral tears.^28,29 FAI lesions include cam-type impingement from an aspherical femoral head and pincer impingement from acetabular overcoverage, both of which limit internal rotation and cause acetabular rim abutment, which damages the labrum.

Athletes present with activity-related groin or hip pain that is exacerbated by hip flexion and internal rotation, with possible mechanical symptoms from labral tearing.³⁰ However, the pain distribution varies. In a study by Clohisy and colleagues,³¹ of patients with symptomatic FAI that required surgical intervention, 88% had groin pain, 67% had lateral hip pain, 35% had anterior thigh pain, 29% had buttock pain, 27% had knee pain, and 23% had low back pain.

Careful attention should be given to range of motion in FAI patients, as they can usually flex their hip to 90° to 110°, and in this position there is limited internal rotation and asymmetric external rotation relative to the contralateral leg.³² The anterior impingement test is one of the most reliable tests for FAI (Figure 5A).³² With the patient supine, the hip is dynamically flexed to 90°, adducted, and internally rotated. A positive test elicits deep anterior groin pain that generally replicates the patient’s symptoms.²⁹

Conclusion

Careful, directed history taking and physical examination are essential in narrowing the diagnostic possibilities before initiating a workup for the common intra-articular and extra-articular causes of hip and groin pain in athletes.

Take-Home Points

• Perform a comprehensive examination to determine intra-articular pathology as well as potential extra-articular sources of hip and pelvic pain.
• Adductor strains can be prevented with adequate rehabilitation focused on correcting predisposing factors (ie, adductor weakness or tightness, limited range of motion, and core imbalance).
• Athletic pubalgia is diagnosed when tenderness can be elicited over the pubic tubercle.
• Osteitis pubis is diagnosed with pain over the pubic symphysis.
• FAI and labral injury classically present with a C-sign but can also present with lateral hip pain, buttock pain, low back pain, anterior thigh pain, and knee pain.

Hip and groin pain is a common finding among athletes of all ages and activity levels. Such pain most often occurs among athletes in sports such as football, hockey, rugby, soccer, and ballet, which demand frequent cutting, pivoting, and acceleration.^1-4 Previously, pain about the hip and groin was attributed to muscular strains and soft-tissue contusions, but improvements in physical examination skills, imaging modalities, and disease-specific treatment options have led to increased recognition of hip injuries as a significant source of disability in the athletic population.^5,6 These injuries make up 6% or more of all sports injuries, and the rate is increasing.^7-9

In this review, we describe precise methods for evaluating the athlete’s hip or groin with an emphasis on recognizing the most common extra-articular and intra-articular pathologies, including adductor strains, athletic pubalgia, osteitis pubis, and femoroacetabular impingement (FAI) with labral tears.

Hip Pathoanatomy

The first step in determining the etiology of pain is to establish if there is true pathology of the hip joint and surrounding structures, or if the pain is referred from another source.

Patient History

The physical examination is guided by the patient’s history. Important patient-specific factors to be ascertained include age, sport(s) played, competition level, seasonal timing, and effect of the injury on performance. Regarding presenting symptoms, attention should be given to pain location, timing (acute vs chronic), onset, nature (clicking, catching, instability), and precipitating factors. Acute-onset pain with muscle contraction or stretching, possibly accompanied by an audible pop, is likely musculotendinous in origin. Insidious-onset dull aching pain that worsens with activity more commonly involves intra-articular processes. Most classically, this pain occurs deep in the groin and is demonstrated by the C sign: The patient cups a hand with its fingers pointing toward the anterior groin at the level of the greater trochanter (Figure 1).¹¹

A comprehensive hip evaluation can be performed with the patient in the standing, seated, supine, lateral, and prone positions, as previously described (Table 2).^6,12,13

Extra-Articular Hip Pathologies

Adductor Strains

The adductor muscle group includes the adductor magnus, adductor brevis, gracilis, obturator externus, pectineus, and adductor longus, which is the most commonly strained. Adductor strains are the most common cause of groin pain in athletes, and usually occur in sports that require forceful eccentric contraction of the adductors.¹⁴ Among professional soccer players, adductor strains represent almost one fourth of all muscle injuries and result in lost playing time averaging 2 weeks and an 18% reinjury rate.¹⁵ These injuries are particularly detrimental to performance because the adductor muscles help stabilize the pelvis during closed-chain activities.³ Diagnosis and adequate rehabilitation focused on correcting predisposing factors (eg, adductor weakness or tightness, loss of hip range of motion, core imbalance) are paramount in reinjury prevention.^16,17

On presentation, athletes complain of aching groin or medial thigh pain. The examiner should assess for swelling or ecchymosis. There typically is tenderness to palpation at or near the origin on the pubic bones, with pain exacerbated with resisted adduction and passive stretch into abduction during examination. Palpation of adductors requires proper exposure and is most easily performed with the patient supine and the lower extremity in a figure-of-4 position (Figure 2A).

Athletic Pubalgia

Athletic pubalgia, also known as sports hernia or core muscle injury, is an injury to the soft tissues of the lower abdominal or posterior inguinal wall. Although not fully understood, the condition is considered the result of repetitive trunk hyperextension and thigh hyperabduction resulting in shearing at the pubic symphysis where there is a muscle imbalance between the strong proximal thigh muscles and weaker abdominals. This condition is more common in men and typically is insidious in onset with a prolonged course recalcitrant to nonoperative treatment.¹⁸ In studies of chronic groin pain in athletes, the rate of athletic pubalgia as the primary etiology ranges from 39% to 85%.^9,19,20

Patients typically complain of increasing pain in the lower abdominal and proximal adductors during activity. Symptoms include unilateral or bilateral lower abdominal pain, which can radiate toward the perineum, rectus muscle, and proximal adductors during sport but usually abates with rest.¹⁸ Athletes endorse they are not capable of playing at their full athletic potential. Symptoms are initiated with sudden forceful movements, as in sit-ups, sprints, and valsalva maneuvers like coughs and sneezes. Valsalva maneuvers worsen pain in about 10% of patients.^21-23On physical examination with the patient supine, tenderness can be elicited over the pubic tubercle, abdominal obliques, and/or rectus abdominis insertion (Figure 3A). Athletes may also have tenderness at the adductor longus tendon origin at or near the pubic symphysis, which may make the diagnosis difficult to distinguish from an adductor strain.

Osteitis Pubis

Osteitis pubis is a painful overuse injury that results in noninfectious inflammation of the pubic symphysis from increased motion at this normally stable immobile joint.³ As with athletic pubalgia, the exact mechanism is unclear, but likely it is similar to the repetitive stress placed on the pubic symphysis by unequal forces of the abdominal and adductor muscles.²⁴ The disease can result in bony erosions and cartilage breakdown with irregularity of the pubic symphysis.

Athletes may complain of anterior and medial groin pain that can radiate to the lower abdominal muscles, perineum, inguinal region, and medial thigh. Walking, pelvic motion, adductor stretching, abdominal muscle exercises, and standing up can exacerbate pain.²⁴ Some cases involve impaired internal or external rotation of the hip, sacroiliac joint dysfunction, or adductor and abductor muscle weakness.²⁵The distinguishing feature of osteitis pubis is pain over the pubic symphysis with direct palpation (Figure 4A). Examination maneuvers that place stress on the pubic symphysis can aid in diagnosis.²⁶

Intra-Articular Hip Pathology: Femoroacetabular Impingement

In athletes, FAI is a leading cause of intra-articular pathology, which can lead to labral tears.^28,29 FAI lesions include cam-type impingement from an aspherical femoral head and pincer impingement from acetabular overcoverage, both of which limit internal rotation and cause acetabular rim abutment, which damages the labrum.

Athletes present with activity-related groin or hip pain that is exacerbated by hip flexion and internal rotation, with possible mechanical symptoms from labral tearing.³⁰ However, the pain distribution varies. In a study by Clohisy and colleagues,³¹ of patients with symptomatic FAI that required surgical intervention, 88% had groin pain, 67% had lateral hip pain, 35% had anterior thigh pain, 29% had buttock pain, 27% had knee pain, and 23% had low back pain.

Careful attention should be given to range of motion in FAI patients, as they can usually flex their hip to 90° to 110°, and in this position there is limited internal rotation and asymmetric external rotation relative to the contralateral leg.³² The anterior impingement test is one of the most reliable tests for FAI (Figure 5A).³² With the patient supine, the hip is dynamically flexed to 90°, adducted, and internally rotated. A positive test elicits deep anterior groin pain that generally replicates the patient’s symptoms.²⁹

Conclusion

Careful, directed history taking and physical examination are essential in narrowing the diagnostic possibilities before initiating a workup for the common intra-articular and extra-articular causes of hip and groin pain in athletes.

Take-Home Points

• Be sure to have a well centered AP pelvis without rotation.
• Get at least 3 plain radiographs—AP pelvis, false profile, and lateral hip view.
• Ensure that there is sufficient acetabular coverage, LCEA >20° on AP pelvis and ACEA >20° on false profile view.
• CT scans are helpful for precise hip pathomor­phology but must be weighed against risk of radiation exposure.
• MRI or MRA can be helpful to diagnose intra-articular as well as extra-articular hip and pelvis abnormalities.

In the work-up for nonarthritic hip pain, the value of diagnostic imaging is in objective findings, which can support or weaken the leading diagnoses based on subjective complaints, recalled history, and, in some cases, elusive physical examination findings. Morphologic changes alone, however, do not always indicate pathology.^1,2 At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Radiography

The first step in diagnostic imaging is radiography. Although use of plain radiographs is routine, their value cannot be understated. Standard hip radiographs—an anteroposterior (AP) radiograph of the pelvis and AP and frog-leg (cross-table lateral) radiographs of the hip—provide a wealth of information.^3-6

Evaluated first is the radiograph itself. For example, the ideal AP radiograph of the pelvis (Figure 1) is centered on the lower sacrum, and the patient is not rotated.

13

Computed Tomography

The benefits of computed tomography (CT) outweigh the risk of radiation exposure. CT is most useful in characterizing osseous morphology.²¹ In FAI cases, CT can distinguish acetabular version abnormalities from femoral torsion (Figures 7A-7C), entities with very different treatment approaches.²¹

Magnetic Resonance Imaging

MRI is becoming essential in the work-up for nonarthritic hip pain.^11,22 It is used for assessment of osseous, chondral, and musculotendinous soft tissues. Further, it affords appreciation of outside-the-hip-joint pathology that may mimic joint-centered pathology.

MRI techniques range from noncontrast to indirect and direct magnetic resonance arthrography (MRA).²² Indirect MRA is performed with contrast medium administered through an intravenous line. Direct MRA has contrast administered intra-articularly and is more sensitive and specific for labral tears and ligamentous injury.²³ Excellent detection of intra-articular pathology on noncontrast studies questions the need for MRA.²⁴ Nevertheless, direct MRA can also be used as a therapeutic procedure when lidocaine is included in the injected gadolinium.

Labral tears, focal chondral defects, and stress or insufficiency fractures are important differentials in the work-up for nonarthritic hip pain. Over the dysplasia-to-FAI spectrum, MRI distinguishes symptomatic pathoanatomy from asymptomatic anatomical variants by revealing underlying bone edema. Capsule findings should also be considered.²¹The most practical classification of labral tears, proposed by Blankenbaker and colleagues,²⁵ is based on tear type (frayed, unstable, flap), location, and extent. More than half of labral tears occur in the anterosuperior quadrant of the labrum.²⁵

26

MRI detects osseous pathology from surrounding soft-tissue edema and bone remodeling to stress and fragility fractures. In athletes, the most common fractures are pubic rami, sacral, and apophyseal avulsion fractures.²⁸ In all patients, attention should be given to the lower spine and the proximal femurs. Aside from MRI, nuclear medicine bone scan might also identify active osseous reaction representative of a fracture.

Conclusion

The work-up for nonarthritic hip pain substantiates differential diagnoses. A case’s complexity determines the course of diagnostic imaging. At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Am J Orthop . 2017;46(1):17-22. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Be sure to have a well centered AP pelvis without rotation.
• Get at least 3 plain radiographs—AP pelvis, false profile, and lateral hip view.
• Ensure that there is sufficient acetabular coverage, LCEA >20° on AP pelvis and ACEA >20° on false profile view.
• CT scans are helpful for precise hip pathomor­phology but must be weighed against risk of radiation exposure.
• MRI or MRA can be helpful to diagnose intra-articular as well as extra-articular hip and pelvis abnormalities.

In the work-up for nonarthritic hip pain, the value of diagnostic imaging is in objective findings, which can support or weaken the leading diagnoses based on subjective complaints, recalled history, and, in some cases, elusive physical examination findings. Morphologic changes alone, however, do not always indicate pathology.^1,2 At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Radiography

The first step in diagnostic imaging is radiography. Although use of plain radiographs is routine, their value cannot be understated. Standard hip radiographs—an anteroposterior (AP) radiograph of the pelvis and AP and frog-leg (cross-table lateral) radiographs of the hip—provide a wealth of information.^3-6

Evaluated first is the radiograph itself. For example, the ideal AP radiograph of the pelvis (Figure 1) is centered on the lower sacrum, and the patient is not rotated.

13

Computed Tomography

The benefits of computed tomography (CT) outweigh the risk of radiation exposure. CT is most useful in characterizing osseous morphology.²¹ In FAI cases, CT can distinguish acetabular version abnormalities from femoral torsion (Figures 7A-7C), entities with very different treatment approaches.²¹

Magnetic Resonance Imaging

MRI is becoming essential in the work-up for nonarthritic hip pain.^11,22 It is used for assessment of osseous, chondral, and musculotendinous soft tissues. Further, it affords appreciation of outside-the-hip-joint pathology that may mimic joint-centered pathology.

MRI techniques range from noncontrast to indirect and direct magnetic resonance arthrography (MRA).²² Indirect MRA is performed with contrast medium administered through an intravenous line. Direct MRA has contrast administered intra-articularly and is more sensitive and specific for labral tears and ligamentous injury.²³ Excellent detection of intra-articular pathology on noncontrast studies questions the need for MRA.²⁴ Nevertheless, direct MRA can also be used as a therapeutic procedure when lidocaine is included in the injected gadolinium.

Labral tears, focal chondral defects, and stress or insufficiency fractures are important differentials in the work-up for nonarthritic hip pain. Over the dysplasia-to-FAI spectrum, MRI distinguishes symptomatic pathoanatomy from asymptomatic anatomical variants by revealing underlying bone edema. Capsule findings should also be considered.²¹The most practical classification of labral tears, proposed by Blankenbaker and colleagues,²⁵ is based on tear type (frayed, unstable, flap), location, and extent. More than half of labral tears occur in the anterosuperior quadrant of the labrum.²⁵

26

MRI detects osseous pathology from surrounding soft-tissue edema and bone remodeling to stress and fragility fractures. In athletes, the most common fractures are pubic rami, sacral, and apophyseal avulsion fractures.²⁸ In all patients, attention should be given to the lower spine and the proximal femurs. Aside from MRI, nuclear medicine bone scan might also identify active osseous reaction representative of a fracture.

Conclusion

The work-up for nonarthritic hip pain substantiates differential diagnoses. A case’s complexity determines the course of diagnostic imaging. At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Am J Orthop . 2017;46(1):17-22. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Be sure to have a well centered AP pelvis without rotation.
• Get at least 3 plain radiographs—AP pelvis, false profile, and lateral hip view.
• Ensure that there is sufficient acetabular coverage, LCEA >20° on AP pelvis and ACEA >20° on false profile view.
• CT scans are helpful for precise hip pathomor­phology but must be weighed against risk of radiation exposure.
• MRI or MRA can be helpful to diagnose intra-articular as well as extra-articular hip and pelvis abnormalities.

In the work-up for nonarthritic hip pain, the value of diagnostic imaging is in objective findings, which can support or weaken the leading diagnoses based on subjective complaints, recalled history, and, in some cases, elusive physical examination findings. Morphologic changes alone, however, do not always indicate pathology.^1,2 At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Radiography

The first step in diagnostic imaging is radiography. Although use of plain radiographs is routine, their value cannot be understated. Standard hip radiographs—an anteroposterior (AP) radiograph of the pelvis and AP and frog-leg (cross-table lateral) radiographs of the hip—provide a wealth of information.^3-6

Evaluated first is the radiograph itself. For example, the ideal AP radiograph of the pelvis (Figure 1) is centered on the lower sacrum, and the patient is not rotated.

13

Computed Tomography

The benefits of computed tomography (CT) outweigh the risk of radiation exposure. CT is most useful in characterizing osseous morphology.²¹ In FAI cases, CT can distinguish acetabular version abnormalities from femoral torsion (Figures 7A-7C), entities with very different treatment approaches.²¹

Magnetic Resonance Imaging

MRI is becoming essential in the work-up for nonarthritic hip pain.^11,22 It is used for assessment of osseous, chondral, and musculotendinous soft tissues. Further, it affords appreciation of outside-the-hip-joint pathology that may mimic joint-centered pathology.

MRI techniques range from noncontrast to indirect and direct magnetic resonance arthrography (MRA).²² Indirect MRA is performed with contrast medium administered through an intravenous line. Direct MRA has contrast administered intra-articularly and is more sensitive and specific for labral tears and ligamentous injury.²³ Excellent detection of intra-articular pathology on noncontrast studies questions the need for MRA.²⁴ Nevertheless, direct MRA can also be used as a therapeutic procedure when lidocaine is included in the injected gadolinium.

Labral tears, focal chondral defects, and stress or insufficiency fractures are important differentials in the work-up for nonarthritic hip pain. Over the dysplasia-to-FAI spectrum, MRI distinguishes symptomatic pathoanatomy from asymptomatic anatomical variants by revealing underlying bone edema. Capsule findings should also be considered.²¹The most practical classification of labral tears, proposed by Blankenbaker and colleagues,²⁵ is based on tear type (frayed, unstable, flap), location, and extent. More than half of labral tears occur in the anterosuperior quadrant of the labrum.²⁵

26

MRI detects osseous pathology from surrounding soft-tissue edema and bone remodeling to stress and fragility fractures. In athletes, the most common fractures are pubic rami, sacral, and apophyseal avulsion fractures.²⁸ In all patients, attention should be given to the lower spine and the proximal femurs. Aside from MRI, nuclear medicine bone scan might also identify active osseous reaction representative of a fracture.

Conclusion

The work-up for nonarthritic hip pain substantiates differential diagnoses. A case’s complexity determines the course of diagnostic imaging. At presentation and at each step in the work-up, it is imperative to evaluate the entire clinical picture. The prudent clinician uses both clinical and radiographic findings to make the diagnosis and direct treatment.

Am J Orthop . 2017;46(1):17-22. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Repair the labrum when tissue quality is good.
• Avoid overcorrection of acetabulum by measuring center edge angle.
• Cam resection should be comprehensive and restore a smooth head-neck offset to restore the suction seal.
• Chondral débridement for Outerbridge grade 0-3 and microfracture for grade 4.
• Routine capsular closure to prevent postoperative instability.

The surgical approach of femoroacetabular impingement (FAI) pathology should cover the entire hip joint. Both bony and cartilaginous tissue pathology should be adequately addressed. However, treating soft-tissue abnormalities (acetabular labrum and joint capsule) is also crucial. Overall, any surgical intervention should focus on restoring the hip labrum seal mechanism to ensure successful clinical outcomes. This restoration, combined with the use of biological therapies and rehabilitation, will produce the maximum benefit for the patient.

Management of Acetabular Labrum

The final decision regarding how to surgically approach the acetabular labrum is made during the operation. We focus restoring the labrum seal mechanism, which is crucial for proper function and health of the hip joint.¹ The intra-articular hydrostatic pressure loss caused by labral deficiency results in abnormal load distribution and joint microinstability, which have detrimental effects on cartilage and periarticular tissues. A biomechanical study highlighted the role of the hip labrum in maintaining intra-articular fluid pressurization and showed that labral reconstruction restores intra-articular fluid pressure to levels similar to those of the intact state.¹

In cases in which the remaining labral tissue is adequate and of good quality (reparable), the labral repair technique is preferred.² After diagnostic arthroscopy, the labral tear is identified, and a 4.5-mm burr is used to correct (rim-trim) any osseous deformity of the acetabulum to create a “new rim” for labrum reattachment. Suture anchors are placed on the rim about 2 mm to 3 mm below the cartilage surface. Considering the rim angle³ is helpful in avoiding acetabular cartilage damage. Labral sutures can be looped around or pierced through the labrum to secure it to the acetabulum. No difference in clinical outcomes was found between the 2 suture types,⁴ though biomechanically piercing sutures help restore the labrum seal better.¹ When the labrum is deficient and longitudinal fibers remain but are insufficient for seal restoration, the repair can be augmented with adjacent iliotibial band (ITB) tissue. This technique is similar to labral reconstruction but involves placing a graft on top of the remaining labral tissue, and suture around both the native tissue and the graft. The additional tissue gives the labrum the volume it needs to recreate the seal.

The labral reconstruction technique is indicated when the remaining labrum is irreparable, absent, or severely hypotrophic or deficient, or when an irreparable complex tear or poor-quality tissue is present. Different types of grafts can be used to reconstruct the labrum. ITB, semitendinosus, gracilis, and anterior tibialis grafts and the human acetabular labrum exhibit similar cyclic elongation behavior in response to simulated physiologic forces, though there is variability in both elongation and geometry for all graft types.⁵ We prefer the ITB autograft technique.⁶ The graft should be about 30% to 40% longer than the labral defect as measured with arthroscopic probe. With the leg in traction, the graft is inserted through the mid-anterior portal, and a suture anchor is used to secure it against the acetabulum medially.

Osseous Deformity

On approaching the bony structures of the hip joint, the surgeon should examine the acetabular rim (pincer lesion), the femoral head and neck shape (cam lesion), and the anterior inferior iliac spine (AIIS). Preoperative imaging and physical examination are important for identifying severe bone deformities that can complicate the procedure.⁹

The acetabular rim can be directly viewed after labrum detachment, but usually complete detachment is not necessary. Pincer deformity causes focal or global overcoverage of the femoral head. Rim trimming is performed with a 4.5-mm round curved burr. Resection is usually performed to the end of rim chondrosis (about 3-5 mm). Using a simple formula, you can calculate how the lateral center edge will be reduced by the amount of rim resected, maintaining a safe margin.² A new acetabular “bed” is created where the to-be-attached labral tissue will contribute to the suction seal mechanism of the joint.²Cam lesion correction is challenging, and the amount of bone that should be resected is a matter of disagreement. We perform cam osteochondroplasty² with a 5.5-mm round burr inserted through the anterolateral portal while the hip is positioned in 45° of flexion, neutral rotation, and adduction/abduction. This position allows an osteoplasty from 6 to 10 o’clock on the head–neck junction. Osteoplasty performed between 10 and 12 o’clock requires hip extension and slight traction. The proximal limit of osteochondroplasty is about 15 mm from the labral edge, while distally the resection stops beneath the zona orbicularis. The lateral epiphyseal vessels and the Weitbrecht ligament constitute the lateral and medial borders, respectively.

The surgeon should create a smooth head–neck offset that prevents elevation of the labrum during flexion and achieves a nearly perfect anatomical relationship between the femoral head and the acetabular labrum, restoring the hip joint seal (Figure 2).

Treatment of Cartilage Lesions

The indications and contraindications for hip arthroscopy in patients with cartilage lesions are important. Our study’s 5-year outcomes of treating FAI with hip arthroscopy in patients with preserved joint space (>2 mm) were promising, though 86% of patients with limited joint space (≤2 mm) converted to total hip arthroplasty.⁸ We regard patients with severe osteoarthritis as not being candidates for hip arthroscopy.

As 3 Tesla magnetic resonance imaging has low positive predictive value in identifying severe cartilage damage,¹³ the cartilage should be examined during surgery to further define the diagnosis. Nearly half of the hip arthroscopy patients in our study had at least 1 Outerbridge grade 3 or 4 cartilage lesion.¹⁴ Compared with the femoral head, acetabular cartilage was damaged 3 times more often. More than 90% of acetabular cartilage lesions were in the anterosuperior region.

Grades 0 and 1 cartilage lesions are usually left untreated; no intervention is necessary. Grades 2 and 3 cartilage lesions are reduced by partial débridement and/or thermal shrinkage. With the improved joint microenvironment arising from simple correction of the underlying hip bony abnormalities, these lesions should not produce further symptoms.

Grade 4 hip cartilage defects are challenging. We prefer microfracture for grade 4 lesions (Figure 4).

Capsule Management

The increase in hip arthroscopies performed worldwide has generated interest in proper capsular management and development of iatrogenic microinstability.¹⁷ Hip capsulotomy is routinely performed for adequate visualization of the intra-articular compartment. Standard anterosuperior interportal capsulotomy for hip arthroscopic surgery (12 to 3 o’clock) sacrifices the integrity of the iliofemoral ligament (ligament of Bigelow),¹⁸ which provides rotational stability. Failure to restore the anatomical and biomechanical properties of the iliofemoral ligament after arthroscopic surgery increases the likelihood of postoperative microinstability or gross instability,¹⁹ which can lead to persistent pain and/or sense of an unstable joint, in addition to accelerated cartilage wear.

Capsulotomies are useful in obtaining adequate intraoperative exposure of the central and peripheral compartments. In the past, little attention was given to capsular closure on completion of the procedure. However, concern about postoperative instability from capsular laxity or deficiency made the introduction of capsular repair techniques necessary. Although deciding between capsular closure and plication remains debatable, we routinely perform capsular closure with a Quebec City slider knot.²⁰ Mindful management of the capsule throughout the procedure is important in avoiding irreversible capsular damage, which would complicate capsular closure. Mindful management involves leaving a proximal leaflet of at least 1 cm during the capsulotomy, avoiding capsular thinning during shaver use, and using a cannula to prevent soft-tissue bridging.

Recent evidence suggests that capsule repair restores near native hip joint stability.¹⁷ In addition to capsular shift or capsulorrhaphy, 2 to 6 sutures have been used for capsular closure or plication after an interportal or T capsulotomy. Chahla and colleagues²¹ reported that 2- and 3-suture constructs produced comparable biomechanical failure torques when external rotation forces were applied to conventional hip capsulotomy on cadavers. Three-suture constructs were significantly stronger than 1-suture constructs, but there was no significant difference between 2- and 3-suture constructs. All constructs failed at about 36° of external rotation. Therefore, restricted external rotation is recommended for 3 weeks after surgery.

In one study, 35% of revision hip arthroscopy patients had undiagnosed hip instability from iatrogenic injury,²² which can lead to labral and chondral injury.¹⁷ Capsular reconstruction is recommended in cases of symptomatic capsular deficiency; capsular deficiency caused by adhesion removal; and pain and range-of-motion limitation caused by capsular adhesions. However, indications need to be further established. We have performed capsular reconstruction with ITB allograft²³ (Figure 5).

Biologics

At the end of the procedure, we use platelet-rich plasma and/or bone marrow aspirate injections (individualized to the patient) to potentiate the biological healing of the tissues. Further research is planned to determine how to prepare these biological products to provide the best mix of biological factors for improved healing. Antifibrotic factors are useful in preventing adhesions, and angiotensin II receptor blockers are effective, but clinical studies are needed to establish their use.

Rehabilitation

Immediately after surgery, a postoperative hip brace and antirotational boots are applied to the patient to protect the operative site and reduce pain. The actual postoperative protocol is based on the procedure and individualized to the patient. During microfractures, the patient is kept 20 pounds touch-toe weight-bearing for 4 to 8 weeks. The capsular closure is brace-protected by limiting abduction to 0° to 45° and hip flexion to 0° to 90° while external rotation and extension are prohibited (first 3 weeks). Immediate mobilization with passive rotational movement is crucial in preventing adhesions. Stationary bike exercise and use of a continuous passive motion machine are helpful. Progressive functional and sport-specific rehabilitation help the patient return to full activity, though the decision to return to full activity is based on several factors, both objective (functional tests) and subjective (physician–patient co-decisions).

Conclusion

Although hip arthroscopic techniques have expanded significantly in recent years, our treatment approach is based on restoring the normal anatomy of the hip joint—combining the procedures with biological therapies and a postoperative rehabilitation program that is individualized to the patient’s special needs.

Am J Orthop. 2017;46(1):23-27. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Repair the labrum when tissue quality is good.
• Avoid overcorrection of acetabulum by measuring center edge angle.
• Cam resection should be comprehensive and restore a smooth head-neck offset to restore the suction seal.
• Chondral débridement for Outerbridge grade 0-3 and microfracture for grade 4.
• Routine capsular closure to prevent postoperative instability.

The surgical approach of femoroacetabular impingement (FAI) pathology should cover the entire hip joint. Both bony and cartilaginous tissue pathology should be adequately addressed. However, treating soft-tissue abnormalities (acetabular labrum and joint capsule) is also crucial. Overall, any surgical intervention should focus on restoring the hip labrum seal mechanism to ensure successful clinical outcomes. This restoration, combined with the use of biological therapies and rehabilitation, will produce the maximum benefit for the patient.

Management of Acetabular Labrum

The final decision regarding how to surgically approach the acetabular labrum is made during the operation. We focus restoring the labrum seal mechanism, which is crucial for proper function and health of the hip joint.¹ The intra-articular hydrostatic pressure loss caused by labral deficiency results in abnormal load distribution and joint microinstability, which have detrimental effects on cartilage and periarticular tissues. A biomechanical study highlighted the role of the hip labrum in maintaining intra-articular fluid pressurization and showed that labral reconstruction restores intra-articular fluid pressure to levels similar to those of the intact state.¹

In cases in which the remaining labral tissue is adequate and of good quality (reparable), the labral repair technique is preferred.² After diagnostic arthroscopy, the labral tear is identified, and a 4.5-mm burr is used to correct (rim-trim) any osseous deformity of the acetabulum to create a “new rim” for labrum reattachment. Suture anchors are placed on the rim about 2 mm to 3 mm below the cartilage surface. Considering the rim angle³ is helpful in avoiding acetabular cartilage damage. Labral sutures can be looped around or pierced through the labrum to secure it to the acetabulum. No difference in clinical outcomes was found between the 2 suture types,⁴ though biomechanically piercing sutures help restore the labrum seal better.¹ When the labrum is deficient and longitudinal fibers remain but are insufficient for seal restoration, the repair can be augmented with adjacent iliotibial band (ITB) tissue. This technique is similar to labral reconstruction but involves placing a graft on top of the remaining labral tissue, and suture around both the native tissue and the graft. The additional tissue gives the labrum the volume it needs to recreate the seal.

The labral reconstruction technique is indicated when the remaining labrum is irreparable, absent, or severely hypotrophic or deficient, or when an irreparable complex tear or poor-quality tissue is present. Different types of grafts can be used to reconstruct the labrum. ITB, semitendinosus, gracilis, and anterior tibialis grafts and the human acetabular labrum exhibit similar cyclic elongation behavior in response to simulated physiologic forces, though there is variability in both elongation and geometry for all graft types.⁵ We prefer the ITB autograft technique.⁶ The graft should be about 30% to 40% longer than the labral defect as measured with arthroscopic probe. With the leg in traction, the graft is inserted through the mid-anterior portal, and a suture anchor is used to secure it against the acetabulum medially.

Osseous Deformity

On approaching the bony structures of the hip joint, the surgeon should examine the acetabular rim (pincer lesion), the femoral head and neck shape (cam lesion), and the anterior inferior iliac spine (AIIS). Preoperative imaging and physical examination are important for identifying severe bone deformities that can complicate the procedure.⁹

The acetabular rim can be directly viewed after labrum detachment, but usually complete detachment is not necessary. Pincer deformity causes focal or global overcoverage of the femoral head. Rim trimming is performed with a 4.5-mm round curved burr. Resection is usually performed to the end of rim chondrosis (about 3-5 mm). Using a simple formula, you can calculate how the lateral center edge will be reduced by the amount of rim resected, maintaining a safe margin.² A new acetabular “bed” is created where the to-be-attached labral tissue will contribute to the suction seal mechanism of the joint.²Cam lesion correction is challenging, and the amount of bone that should be resected is a matter of disagreement. We perform cam osteochondroplasty² with a 5.5-mm round burr inserted through the anterolateral portal while the hip is positioned in 45° of flexion, neutral rotation, and adduction/abduction. This position allows an osteoplasty from 6 to 10 o’clock on the head–neck junction. Osteoplasty performed between 10 and 12 o’clock requires hip extension and slight traction. The proximal limit of osteochondroplasty is about 15 mm from the labral edge, while distally the resection stops beneath the zona orbicularis. The lateral epiphyseal vessels and the Weitbrecht ligament constitute the lateral and medial borders, respectively.

The surgeon should create a smooth head–neck offset that prevents elevation of the labrum during flexion and achieves a nearly perfect anatomical relationship between the femoral head and the acetabular labrum, restoring the hip joint seal (Figure 2).

Treatment of Cartilage Lesions

The indications and contraindications for hip arthroscopy in patients with cartilage lesions are important. Our study’s 5-year outcomes of treating FAI with hip arthroscopy in patients with preserved joint space (>2 mm) were promising, though 86% of patients with limited joint space (≤2 mm) converted to total hip arthroplasty.⁸ We regard patients with severe osteoarthritis as not being candidates for hip arthroscopy.

As 3 Tesla magnetic resonance imaging has low positive predictive value in identifying severe cartilage damage,¹³ the cartilage should be examined during surgery to further define the diagnosis. Nearly half of the hip arthroscopy patients in our study had at least 1 Outerbridge grade 3 or 4 cartilage lesion.¹⁴ Compared with the femoral head, acetabular cartilage was damaged 3 times more often. More than 90% of acetabular cartilage lesions were in the anterosuperior region.

Grades 0 and 1 cartilage lesions are usually left untreated; no intervention is necessary. Grades 2 and 3 cartilage lesions are reduced by partial débridement and/or thermal shrinkage. With the improved joint microenvironment arising from simple correction of the underlying hip bony abnormalities, these lesions should not produce further symptoms.

Grade 4 hip cartilage defects are challenging. We prefer microfracture for grade 4 lesions (Figure 4).

Capsule Management

The increase in hip arthroscopies performed worldwide has generated interest in proper capsular management and development of iatrogenic microinstability.¹⁷ Hip capsulotomy is routinely performed for adequate visualization of the intra-articular compartment. Standard anterosuperior interportal capsulotomy for hip arthroscopic surgery (12 to 3 o’clock) sacrifices the integrity of the iliofemoral ligament (ligament of Bigelow),¹⁸ which provides rotational stability. Failure to restore the anatomical and biomechanical properties of the iliofemoral ligament after arthroscopic surgery increases the likelihood of postoperative microinstability or gross instability,¹⁹ which can lead to persistent pain and/or sense of an unstable joint, in addition to accelerated cartilage wear.

Capsulotomies are useful in obtaining adequate intraoperative exposure of the central and peripheral compartments. In the past, little attention was given to capsular closure on completion of the procedure. However, concern about postoperative instability from capsular laxity or deficiency made the introduction of capsular repair techniques necessary. Although deciding between capsular closure and plication remains debatable, we routinely perform capsular closure with a Quebec City slider knot.²⁰ Mindful management of the capsule throughout the procedure is important in avoiding irreversible capsular damage, which would complicate capsular closure. Mindful management involves leaving a proximal leaflet of at least 1 cm during the capsulotomy, avoiding capsular thinning during shaver use, and using a cannula to prevent soft-tissue bridging.

Recent evidence suggests that capsule repair restores near native hip joint stability.¹⁷ In addition to capsular shift or capsulorrhaphy, 2 to 6 sutures have been used for capsular closure or plication after an interportal or T capsulotomy. Chahla and colleagues²¹ reported that 2- and 3-suture constructs produced comparable biomechanical failure torques when external rotation forces were applied to conventional hip capsulotomy on cadavers. Three-suture constructs were significantly stronger than 1-suture constructs, but there was no significant difference between 2- and 3-suture constructs. All constructs failed at about 36° of external rotation. Therefore, restricted external rotation is recommended for 3 weeks after surgery.

In one study, 35% of revision hip arthroscopy patients had undiagnosed hip instability from iatrogenic injury,²² which can lead to labral and chondral injury.¹⁷ Capsular reconstruction is recommended in cases of symptomatic capsular deficiency; capsular deficiency caused by adhesion removal; and pain and range-of-motion limitation caused by capsular adhesions. However, indications need to be further established. We have performed capsular reconstruction with ITB allograft²³ (Figure 5).

Biologics

At the end of the procedure, we use platelet-rich plasma and/or bone marrow aspirate injections (individualized to the patient) to potentiate the biological healing of the tissues. Further research is planned to determine how to prepare these biological products to provide the best mix of biological factors for improved healing. Antifibrotic factors are useful in preventing adhesions, and angiotensin II receptor blockers are effective, but clinical studies are needed to establish their use.

Rehabilitation

Immediately after surgery, a postoperative hip brace and antirotational boots are applied to the patient to protect the operative site and reduce pain. The actual postoperative protocol is based on the procedure and individualized to the patient. During microfractures, the patient is kept 20 pounds touch-toe weight-bearing for 4 to 8 weeks. The capsular closure is brace-protected by limiting abduction to 0° to 45° and hip flexion to 0° to 90° while external rotation and extension are prohibited (first 3 weeks). Immediate mobilization with passive rotational movement is crucial in preventing adhesions. Stationary bike exercise and use of a continuous passive motion machine are helpful. Progressive functional and sport-specific rehabilitation help the patient return to full activity, though the decision to return to full activity is based on several factors, both objective (functional tests) and subjective (physician–patient co-decisions).

Conclusion

Although hip arthroscopic techniques have expanded significantly in recent years, our treatment approach is based on restoring the normal anatomy of the hip joint—combining the procedures with biological therapies and a postoperative rehabilitation program that is individualized to the patient’s special needs.

Am J Orthop. 2017;46(1):23-27. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Repair the labrum when tissue quality is good.
• Avoid overcorrection of acetabulum by measuring center edge angle.
• Cam resection should be comprehensive and restore a smooth head-neck offset to restore the suction seal.
• Chondral débridement for Outerbridge grade 0-3 and microfracture for grade 4.
• Routine capsular closure to prevent postoperative instability.

The surgical approach of femoroacetabular impingement (FAI) pathology should cover the entire hip joint. Both bony and cartilaginous tissue pathology should be adequately addressed. However, treating soft-tissue abnormalities (acetabular labrum and joint capsule) is also crucial. Overall, any surgical intervention should focus on restoring the hip labrum seal mechanism to ensure successful clinical outcomes. This restoration, combined with the use of biological therapies and rehabilitation, will produce the maximum benefit for the patient.

Management of Acetabular Labrum

The final decision regarding how to surgically approach the acetabular labrum is made during the operation. We focus restoring the labrum seal mechanism, which is crucial for proper function and health of the hip joint.¹ The intra-articular hydrostatic pressure loss caused by labral deficiency results in abnormal load distribution and joint microinstability, which have detrimental effects on cartilage and periarticular tissues. A biomechanical study highlighted the role of the hip labrum in maintaining intra-articular fluid pressurization and showed that labral reconstruction restores intra-articular fluid pressure to levels similar to those of the intact state.¹

In cases in which the remaining labral tissue is adequate and of good quality (reparable), the labral repair technique is preferred.² After diagnostic arthroscopy, the labral tear is identified, and a 4.5-mm burr is used to correct (rim-trim) any osseous deformity of the acetabulum to create a “new rim” for labrum reattachment. Suture anchors are placed on the rim about 2 mm to 3 mm below the cartilage surface. Considering the rim angle³ is helpful in avoiding acetabular cartilage damage. Labral sutures can be looped around or pierced through the labrum to secure it to the acetabulum. No difference in clinical outcomes was found between the 2 suture types,⁴ though biomechanically piercing sutures help restore the labrum seal better.¹ When the labrum is deficient and longitudinal fibers remain but are insufficient for seal restoration, the repair can be augmented with adjacent iliotibial band (ITB) tissue. This technique is similar to labral reconstruction but involves placing a graft on top of the remaining labral tissue, and suture around both the native tissue and the graft. The additional tissue gives the labrum the volume it needs to recreate the seal.

The labral reconstruction technique is indicated when the remaining labrum is irreparable, absent, or severely hypotrophic or deficient, or when an irreparable complex tear or poor-quality tissue is present. Different types of grafts can be used to reconstruct the labrum. ITB, semitendinosus, gracilis, and anterior tibialis grafts and the human acetabular labrum exhibit similar cyclic elongation behavior in response to simulated physiologic forces, though there is variability in both elongation and geometry for all graft types.⁵ We prefer the ITB autograft technique.⁶ The graft should be about 30% to 40% longer than the labral defect as measured with arthroscopic probe. With the leg in traction, the graft is inserted through the mid-anterior portal, and a suture anchor is used to secure it against the acetabulum medially.

Osseous Deformity

On approaching the bony structures of the hip joint, the surgeon should examine the acetabular rim (pincer lesion), the femoral head and neck shape (cam lesion), and the anterior inferior iliac spine (AIIS). Preoperative imaging and physical examination are important for identifying severe bone deformities that can complicate the procedure.⁹

The acetabular rim can be directly viewed after labrum detachment, but usually complete detachment is not necessary. Pincer deformity causes focal or global overcoverage of the femoral head. Rim trimming is performed with a 4.5-mm round curved burr. Resection is usually performed to the end of rim chondrosis (about 3-5 mm). Using a simple formula, you can calculate how the lateral center edge will be reduced by the amount of rim resected, maintaining a safe margin.² A new acetabular “bed” is created where the to-be-attached labral tissue will contribute to the suction seal mechanism of the joint.²Cam lesion correction is challenging, and the amount of bone that should be resected is a matter of disagreement. We perform cam osteochondroplasty² with a 5.5-mm round burr inserted through the anterolateral portal while the hip is positioned in 45° of flexion, neutral rotation, and adduction/abduction. This position allows an osteoplasty from 6 to 10 o’clock on the head–neck junction. Osteoplasty performed between 10 and 12 o’clock requires hip extension and slight traction. The proximal limit of osteochondroplasty is about 15 mm from the labral edge, while distally the resection stops beneath the zona orbicularis. The lateral epiphyseal vessels and the Weitbrecht ligament constitute the lateral and medial borders, respectively.

The surgeon should create a smooth head–neck offset that prevents elevation of the labrum during flexion and achieves a nearly perfect anatomical relationship between the femoral head and the acetabular labrum, restoring the hip joint seal (Figure 2).

Treatment of Cartilage Lesions

The indications and contraindications for hip arthroscopy in patients with cartilage lesions are important. Our study’s 5-year outcomes of treating FAI with hip arthroscopy in patients with preserved joint space (>2 mm) were promising, though 86% of patients with limited joint space (≤2 mm) converted to total hip arthroplasty.⁸ We regard patients with severe osteoarthritis as not being candidates for hip arthroscopy.

As 3 Tesla magnetic resonance imaging has low positive predictive value in identifying severe cartilage damage,¹³ the cartilage should be examined during surgery to further define the diagnosis. Nearly half of the hip arthroscopy patients in our study had at least 1 Outerbridge grade 3 or 4 cartilage lesion.¹⁴ Compared with the femoral head, acetabular cartilage was damaged 3 times more often. More than 90% of acetabular cartilage lesions were in the anterosuperior region.

Grades 0 and 1 cartilage lesions are usually left untreated; no intervention is necessary. Grades 2 and 3 cartilage lesions are reduced by partial débridement and/or thermal shrinkage. With the improved joint microenvironment arising from simple correction of the underlying hip bony abnormalities, these lesions should not produce further symptoms.

Grade 4 hip cartilage defects are challenging. We prefer microfracture for grade 4 lesions (Figure 4).

Capsule Management

The increase in hip arthroscopies performed worldwide has generated interest in proper capsular management and development of iatrogenic microinstability.¹⁷ Hip capsulotomy is routinely performed for adequate visualization of the intra-articular compartment. Standard anterosuperior interportal capsulotomy for hip arthroscopic surgery (12 to 3 o’clock) sacrifices the integrity of the iliofemoral ligament (ligament of Bigelow),¹⁸ which provides rotational stability. Failure to restore the anatomical and biomechanical properties of the iliofemoral ligament after arthroscopic surgery increases the likelihood of postoperative microinstability or gross instability,¹⁹ which can lead to persistent pain and/or sense of an unstable joint, in addition to accelerated cartilage wear.

Capsulotomies are useful in obtaining adequate intraoperative exposure of the central and peripheral compartments. In the past, little attention was given to capsular closure on completion of the procedure. However, concern about postoperative instability from capsular laxity or deficiency made the introduction of capsular repair techniques necessary. Although deciding between capsular closure and plication remains debatable, we routinely perform capsular closure with a Quebec City slider knot.²⁰ Mindful management of the capsule throughout the procedure is important in avoiding irreversible capsular damage, which would complicate capsular closure. Mindful management involves leaving a proximal leaflet of at least 1 cm during the capsulotomy, avoiding capsular thinning during shaver use, and using a cannula to prevent soft-tissue bridging.

Recent evidence suggests that capsule repair restores near native hip joint stability.¹⁷ In addition to capsular shift or capsulorrhaphy, 2 to 6 sutures have been used for capsular closure or plication after an interportal or T capsulotomy. Chahla and colleagues²¹ reported that 2- and 3-suture constructs produced comparable biomechanical failure torques when external rotation forces were applied to conventional hip capsulotomy on cadavers. Three-suture constructs were significantly stronger than 1-suture constructs, but there was no significant difference between 2- and 3-suture constructs. All constructs failed at about 36° of external rotation. Therefore, restricted external rotation is recommended for 3 weeks after surgery.

In one study, 35% of revision hip arthroscopy patients had undiagnosed hip instability from iatrogenic injury,²² which can lead to labral and chondral injury.¹⁷ Capsular reconstruction is recommended in cases of symptomatic capsular deficiency; capsular deficiency caused by adhesion removal; and pain and range-of-motion limitation caused by capsular adhesions. However, indications need to be further established. We have performed capsular reconstruction with ITB allograft²³ (Figure 5).

Biologics

At the end of the procedure, we use platelet-rich plasma and/or bone marrow aspirate injections (individualized to the patient) to potentiate the biological healing of the tissues. Further research is planned to determine how to prepare these biological products to provide the best mix of biological factors for improved healing. Antifibrotic factors are useful in preventing adhesions, and angiotensin II receptor blockers are effective, but clinical studies are needed to establish their use.

Rehabilitation

Immediately after surgery, a postoperative hip brace and antirotational boots are applied to the patient to protect the operative site and reduce pain. The actual postoperative protocol is based on the procedure and individualized to the patient. During microfractures, the patient is kept 20 pounds touch-toe weight-bearing for 4 to 8 weeks. The capsular closure is brace-protected by limiting abduction to 0° to 45° and hip flexion to 0° to 90° while external rotation and extension are prohibited (first 3 weeks). Immediate mobilization with passive rotational movement is crucial in preventing adhesions. Stationary bike exercise and use of a continuous passive motion machine are helpful. Progressive functional and sport-specific rehabilitation help the patient return to full activity, though the decision to return to full activity is based on several factors, both objective (functional tests) and subjective (physician–patient co-decisions).

Conclusion

Although hip arthroscopic techniques have expanded significantly in recent years, our treatment approach is based on restoring the normal anatomy of the hip joint—combining the procedures with biological therapies and a postoperative rehabilitation program that is individualized to the patient’s special needs.

Am J Orthop. 2017;46(1):23-27. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Our understanding of FAI has evolved from cam-type and pincer-type impingement to much more complex disease patterns.
• Most surgeons are performing less aggressive acetabular rim trimming.
• Inadequate osseous correction is still the most common cause of the failed hip arthroscopy.
• Labral preservation is important to maintaining suction seal effect.
• Open surgical techniques have a role for more severe and complex FAI deformities.

Femoroacetabular impingement (FAI) was described by Ganz and colleagues¹ in 2003 as a refinement of concepts introduced decades earlier. This description advanced our understanding of FAI as a mechanism for prearthritic hip pain and secondary hip osteoarthritis¹ (OA) and allowed for treatment of FAI. The concept of proximal femoral and acetabular/pelvic deformity contributing to OA had been previously speculated by Smith-Petersen,² Murray,³ Solomon,⁴ and Stulberg.⁵ Early cases of overcorrection of dysplasia using the periacetabular osteotomy created iatrogenic FAI, which further stimulated early development of the FAI concept.⁶ Improved anatomical characterization of the proximal femoral blood supply (medial femoral circumflex artery) allowed for development of the open surgical hip dislocation.⁷ Through open surgical hip dislocation, an improved understanding of hip pathomechanics by direct visualization helped pave the way for a better understanding of FAI. Open surgical hip dislocation allows for global treatment of labrochondral pathology and deformity of the proximal femoral head–neck junction and/or acetabular rim in FAI.

Hip arthroscopy has further developed and improved our understanding of FAI. Early hip arthroscopy was generally limited to débridement of labral and chondral pathology, and management of the soft-tissue structures. Advances in the understanding of FAI through open techniques allowed for application of similar techniques to hip arthroscopy. Improvements in arthroscopic instrumentation and techniques have allowed for treatment of labrochondral and acetabular-sided rim deformity in the central compartment and cam morphologies in the peripheral compartment through arthroscopic surgery. Appropriate bony correction by arthroscopic techniques has always been a concern, but improved techniques, dynamic assessment, and accurate use of intraoperative imaging have made this feasible and more predictable. Treatment of cam deformities extending adjacent and proximal to the retinacular vessels is possible but more technically demanding. Inadequate bony correction of FAI by arthroscopic means remains one of the most common causes of failure.^8-10In 2013, the Academic Network of Conservational Hip Outcome Research (ANCHOR) Study Group reported the characteristics of a FAI cohort of 1130 hips (1076 patients) that underwent surgical treatment of FAI across 8 institutions and 12 surgeons.¹¹ At that time, most ANCHOR surgeons (or surgeon groups) performed both open and arthroscopic surgeries and had significant referral volumes of complex cases that may have overrepresented the proportion of complex FAI cases in the cohort. During the 2008 to 2011 study period, FAI was treated with arthroscopy in 56% of these cases, open surgical hip dislocation in 34%, and reverse periacetabular osteotomy in 9%. FAI was characterized as isolated cam-type in 48%, combined cam–pincer type in 45%, and isolated pincer-type in 8%. Fifty-five percent of the patients were female. Patient-reported outcome studies in this cohort of patients are ongoing.

The FAI Concept

In 2003, after treating more than 600 open surgical hip dislocations over the previous decade, Ganz and colleagues¹ coined the term femoroacetabular impingement to describe a “mechanism for the development of early osteoarthritis for most nondysplastic hips.” They reported surgical treatment focused on “improving the clearance for hip motion and alleviation of femoral abutment against the acetabular rim” with the goal of improving pain and possibly of halting progression of the degenerative process. FAI was defined as “abnormal contact between the proximal femur and acetabular rim that occurs during terminal motion of the hip” leading to “lesions of the acetabular labrum and/or the adjacent acetabular cartilage.” Subtle, previously overlooked deformities of the proximal femur and acetabulum were recognized as the cause of FAI, “including the presence of a bony prominence usually in the anterolateral head and neck junction that is seen best on the lateral radiographs, reduced offset of the femoral neck and head junction, and changes on the acetabular rim such as os acetabuli or a double line that is seen with rim ossification.” Ganz and colleagues¹ recognized that “normal or near normal” hips could also experience FAI in the setting of excessive or supraphysiologic range of motion. Cam-type and pincer-type FAI deformities were introduced as 2 distinct mechanisms of FAI. By 2003, arthroscopic hip surgery was increasingly being used as a treatment for labral tears but not bony abnormalities. These FAI concepts seemed to explain the prevalence of labral tears at the anterosuperior rim, which had been noted during hip arthroscopy, and paved the way for major changes in arthroscopic hip surgery during the next decade. The ANCHOR group reported the descriptive epidemiology of a cohort of more than 1000 patients with FAI.¹¹

Cam-Type FAI

Cam-type impingement results from femoral-sided deformities. The mechanism was described as inclusion-type impingement in which “jamming of an abnormal femoral head with increasing radius into the acetabulum during forceful motion, especially flexion.”¹ This results in outside-in abrasion of the acetabular cartilage of the anterosuperior rim with detachment of the “principally uninvolved labrum”¹ and potentially delamination of the adjacent cartilage from the subchondral bone. Ganz and colleagues¹ recognized in their initial descriptions of FAI that cam-type FAI could involve decreased femoral version, femoral head–neck junction asphericity, and decreased head–neck offset. The complexity and variability in the topography and geography of the cam morphology have been increasingly recognized. Accurate understanding and characterization of the proximal femoral deformity are important in guiding surgical correction of the cam deformity.

Advances in understanding the prevalence of the cam morphology and the association with OA have been important to our understanding of the pathophysiology of FAI. Several studies¹² have established that a cam morphology of the proximal femur (defined by a variety of different metrics) is common among asymptomatic individuals. In light of this fact, a description of the femoral anatomy as a “cam morphology” rather than a cam deformity is now favored. Similarly, FAI is better used to refer to symptomatic individuals and is not equivalent to a cam morphology. The cam morphology seems significantly more common among athletes. Siebenrock and colleagues¹³ demonstrated the correlation of high-level athletics during late stages of skeletal immaturity and development of a cam morphology. A recent systematic review of 9 studies found that elite male athletes in late skeletal immaturity were 2 to 8 times more likely to develop a cam morphology before skeletal maturity.¹⁴Several population-based studies^15,16 have quantified the apparent association of the cam morphology with hip OA. However, the studies were limited in their ability to adequately define the presence of cam morphology based on anteroposterior (AP) pelvis radiographs.

In a prospective study, Agricola and colleagues¹⁵ found the risk of OA was increased 2.4 times in the setting of moderate cam morphology (α angle, >60°) over a 5-year period. Thomas and colleagues¹⁶ found increased risk in a female cohort when the α angle was >65°.

Treatment of cam-type FAI is focused on adequate correction of the abnormal bone morphology. Inadequate or inappropriate bony correction of FAI is a common cause of treatment failure and is more common with arthroscopic techniques.^9,10,17 Inadequate bony resection may be the result of surgical inexperience, poor visualization, or lack of understanding of the underlying bony deformity. Modern osteoplasty techniques also focus on gradual bony contour correction that restores the normal concavity–convexity transition of the head–neck junction. Overresection of the cam deformity not only may increase the risk of femoral neck fracture but may result in early disruption of the hip fluid seal from loss of contact between the femoral head and the acetabular labrum earlier in the arc of motion. In addition, high range-of-motion impingement can be seen in various athletic populations (dance, gymnastics, martial arts, hockey goalies), and the regions of impingement tend to be farther away from classically described impingement. Impingement in these situations occurs at the distal femoral neck and subspine regions, adding a level of complexity and unpredictability from a surgical standpoint.

FAI can also occur in the setting of more complex deformities than the typical cam morphology. Complex cases of FAI caused by slipped capital femoral epiphysis (SCFE) and residual Legg-Calvé-Perthes disease are relatively common. Complex deformities may also result in extra-articular impingement of the proximal femur (greater/lesser trochanter, distal femoral neck) on the pelvis (ilium, ischium) in addition to typical FAI. Mild to moderate cases of residual SCFE may be adequately treated with osteoplasty by arthroscopic techniques. In the setting of more severe residual SCFE, presence of underlying femoral retroversion and retrotilt of the femoral epiphysis may prevent adequate deformity correction and motion improvement by arthroscopy. Surgical hip dislocation (with or without relative femoral neck lengthening) and/or proximal femoral flexion derotational osteotomy may be the best means of treatment in these more severe deformities but may be dependent on the chronicity of the deformity and associated compensatory changes occurring on the acetabular side. Similarly, in moderate to severe residual Legg-Calvé-Perthes disease, presence of coxa vara, high greater trochanter, short femoral neck, and ovoid femoral head may be better treated in open techniques to allow comprehensive deformity correction, including correction of acetabular dysplasia in some cases.

Pincer-Type FAI

Pincer-type FAI results from acetabular-sided deformities in which acetabular deformity leads to impaction-type impingement with “linear contact between the acetabular rim and the femoral head–neck junction.”¹ Pincer FAI causes primarily labral damage with progressive degeneration and, in some cases, ossification of the acetabular labrum that further worsens the acetabular overcoverage and premature rim impaction. Chondral damage in pincer-type FAI is generally less significant and limited to the peripheral acetabular rim.

Pincer-type FAI may be caused by acetabular retroversion, coxa profunda, or protrusio acetabuli. Our understanding of what defines a pincer morphology has evolved significantly. Through efforts to better define structural features of the acetabular rim that represent abnormalities, we have improved our understanding of how these features may influence OA development. One example of improved understanding involves coxa profunda, classically defined as the medial acetabular fossa touching or projecting medial to the ilioischial line on an AP pelvis radiograph. Several studies have found that this classic definition poorly describes the “overcovered” hip, as it is present in 70% of females and commonly present (41%) in the setting of acetabular dysplasia.^18,19 Acetabular retroversion was previously associated with hip OA. Although central acetabular retroversion is relatively uncommon, cranial acetabular retroversion is more common. Presence of a crossover sign on AP pelvis radiographs generally has been viewed as indicative of acetabular retroversion. However, alterations in pelvic tilt on supine or standing AP pelvis radiographs can result in apparent retroversion in the setting of normal acetabular anatomy²⁰ and potentially influence the development of impingement.²¹ Zaltz and colleagues²² found that abnormal morphology of the anterior inferior iliac spine can also lead to the presence of a crossover sign in an otherwise anteverted acetabulum. Larson and colleagues²³ recently found that a crossover sign is present in 11% of asymptomatic hips (19% of males) and may be considered a normal variant. A crossover sign can also be present in the setting of posterior acetabular deficiency with normal anterior acetabular coverage. Ultimately, acetabular retroversion might indicate pincer-type FAI or dysplasia or be a normal variant that does not require treatment. Global acetabular overcoverage, including coxa protrusio, may be associated with OA in population-based studies but is not uniformly demonstrated in all studies.^16,24,25 A lateral center edge angle of >40° and a Tönnis angle (acetabular inclination) of <0° are commonly viewed as markers of global overcoverage.

FAI Treatment

Improvements in hip arthroscopy techniques and instrumentation have led to hip arthroscopy becoming the primary surgical technique for the treatment of most cases of FAI. Hip arthroscopy allows for precise visualization and treatment of labral and chondral disease in the central compartment by traction. Larson and colleagues²⁶ reported complication rates for hip arthroscopy in a prospective series of >1600 cases. The overall complication rate was 8.3%, with higher rates noted in female patients and in the setting of traction time longer than 60 minutes. Nonetheless, major complications occurred in 1.1%, with only 0.1% having persistent disability. The most common complications were lateral femoral cutaneous nerve dysesthesias (1.6%), pudendal nerve neuropraxia (1.4%), and iatrogenic labral/chondral damage (2.1%).

The importance of preserving the acetabular labrum is now well accepted from clinical and biomechanical evidence.^27-29 As in previous studies in surgical hip dislocation,³⁰ arthroscopic labral repair (vs débridement) results in improved clinical outcomes.^31,32 Labral repair techniques currently focus on stable fixation of the labrum while maintaining the normal position of the labrum relative to the femoral head and avoiding labral eversion, which may compromise the hip suction seal. With continued technical advancements and biomechanical support, arthroscopic labral reconstruction is possible in the setting of labral deficiency, often resulting from prior resection. However, the optimal indications, surgical techniques, and long-term outcomes continue to be better defined. Open and arthroscopic techniques have shown similar ability to correct the typical mild to moderate cam morphology in FAI.³³ Yet, inadequate femoral bony correction of FAI seems to be the most common cause for revision hip preservation surgery.^9,10,17Mild to moderate acetabular rim deformities are commonly treated with hip arthroscopy. As our understanding of pincer-type FAI continues to improve, many surgeons are performing less- aggressive bone resection along the anterior rim. On the other hand, subspinous impingement was recently recognized as a form of extra-articular pincer FAI variant.³⁴ Subspine decompression without true acetabular rim resection has become a more common treatment for pincer lesions and may be a consideration even with restricted range of motion after periacetabular osteotomy. Severe acetabular deformities with global overcoverage or acetabular protrusion are particularly challenging by arthroscopy, even for the most experienced surgeons. Although some improvement in deformity is feasible with arthroscopy, even cases reported in the literature have demonstrated incomplete deformity correction. Open surgical hip dislocation may continue to be the ideal treatment technique for severe pincer impingement.

Cam-type FAI is commonly treated with hip arthroscopy (Figures A-F).

Conclusion

Our understanding and treatment of FAI continue to evolve. Both open and arthroscopic techniques have demonstrated excellent outcomes in the treatment of FAI. Most cases of FAI are now amenable to arthroscopic treatment. Inadequate resection and underlying acetabular dysplasia remain common causes of treatment failure. Open surgical hip dislocation continues to play a role in the treatment of severe deformities that are poorly accessible by arthroscopy—including cam lesions with posterior extension, severe global acetabular overcoverage, or extra-articular impingement. The association of FAI with OA is most apparent for cam-type FAI. Future research will define the optimal treatment strategies and determine if they modify disease progression.

Am J Orthop. 2017;46(1):28-34. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Our understanding of FAI has evolved from cam-type and pincer-type impingement to much more complex disease patterns.
• Most surgeons are performing less aggressive acetabular rim trimming.
• Inadequate osseous correction is still the most common cause of the failed hip arthroscopy.
• Labral preservation is important to maintaining suction seal effect.
• Open surgical techniques have a role for more severe and complex FAI deformities.

Femoroacetabular impingement (FAI) was described by Ganz and colleagues¹ in 2003 as a refinement of concepts introduced decades earlier. This description advanced our understanding of FAI as a mechanism for prearthritic hip pain and secondary hip osteoarthritis¹ (OA) and allowed for treatment of FAI. The concept of proximal femoral and acetabular/pelvic deformity contributing to OA had been previously speculated by Smith-Petersen,² Murray,³ Solomon,⁴ and Stulberg.⁵ Early cases of overcorrection of dysplasia using the periacetabular osteotomy created iatrogenic FAI, which further stimulated early development of the FAI concept.⁶ Improved anatomical characterization of the proximal femoral blood supply (medial femoral circumflex artery) allowed for development of the open surgical hip dislocation.⁷ Through open surgical hip dislocation, an improved understanding of hip pathomechanics by direct visualization helped pave the way for a better understanding of FAI. Open surgical hip dislocation allows for global treatment of labrochondral pathology and deformity of the proximal femoral head–neck junction and/or acetabular rim in FAI.

Hip arthroscopy has further developed and improved our understanding of FAI. Early hip arthroscopy was generally limited to débridement of labral and chondral pathology, and management of the soft-tissue structures. Advances in the understanding of FAI through open techniques allowed for application of similar techniques to hip arthroscopy. Improvements in arthroscopic instrumentation and techniques have allowed for treatment of labrochondral and acetabular-sided rim deformity in the central compartment and cam morphologies in the peripheral compartment through arthroscopic surgery. Appropriate bony correction by arthroscopic techniques has always been a concern, but improved techniques, dynamic assessment, and accurate use of intraoperative imaging have made this feasible and more predictable. Treatment of cam deformities extending adjacent and proximal to the retinacular vessels is possible but more technically demanding. Inadequate bony correction of FAI by arthroscopic means remains one of the most common causes of failure.^8-10In 2013, the Academic Network of Conservational Hip Outcome Research (ANCHOR) Study Group reported the characteristics of a FAI cohort of 1130 hips (1076 patients) that underwent surgical treatment of FAI across 8 institutions and 12 surgeons.¹¹ At that time, most ANCHOR surgeons (or surgeon groups) performed both open and arthroscopic surgeries and had significant referral volumes of complex cases that may have overrepresented the proportion of complex FAI cases in the cohort. During the 2008 to 2011 study period, FAI was treated with arthroscopy in 56% of these cases, open surgical hip dislocation in 34%, and reverse periacetabular osteotomy in 9%. FAI was characterized as isolated cam-type in 48%, combined cam–pincer type in 45%, and isolated pincer-type in 8%. Fifty-five percent of the patients were female. Patient-reported outcome studies in this cohort of patients are ongoing.

The FAI Concept

In 2003, after treating more than 600 open surgical hip dislocations over the previous decade, Ganz and colleagues¹ coined the term femoroacetabular impingement to describe a “mechanism for the development of early osteoarthritis for most nondysplastic hips.” They reported surgical treatment focused on “improving the clearance for hip motion and alleviation of femoral abutment against the acetabular rim” with the goal of improving pain and possibly of halting progression of the degenerative process. FAI was defined as “abnormal contact between the proximal femur and acetabular rim that occurs during terminal motion of the hip” leading to “lesions of the acetabular labrum and/or the adjacent acetabular cartilage.” Subtle, previously overlooked deformities of the proximal femur and acetabulum were recognized as the cause of FAI, “including the presence of a bony prominence usually in the anterolateral head and neck junction that is seen best on the lateral radiographs, reduced offset of the femoral neck and head junction, and changes on the acetabular rim such as os acetabuli or a double line that is seen with rim ossification.” Ganz and colleagues¹ recognized that “normal or near normal” hips could also experience FAI in the setting of excessive or supraphysiologic range of motion. Cam-type and pincer-type FAI deformities were introduced as 2 distinct mechanisms of FAI. By 2003, arthroscopic hip surgery was increasingly being used as a treatment for labral tears but not bony abnormalities. These FAI concepts seemed to explain the prevalence of labral tears at the anterosuperior rim, which had been noted during hip arthroscopy, and paved the way for major changes in arthroscopic hip surgery during the next decade. The ANCHOR group reported the descriptive epidemiology of a cohort of more than 1000 patients with FAI.¹¹

Cam-Type FAI

Cam-type impingement results from femoral-sided deformities. The mechanism was described as inclusion-type impingement in which “jamming of an abnormal femoral head with increasing radius into the acetabulum during forceful motion, especially flexion.”¹ This results in outside-in abrasion of the acetabular cartilage of the anterosuperior rim with detachment of the “principally uninvolved labrum”¹ and potentially delamination of the adjacent cartilage from the subchondral bone. Ganz and colleagues¹ recognized in their initial descriptions of FAI that cam-type FAI could involve decreased femoral version, femoral head–neck junction asphericity, and decreased head–neck offset. The complexity and variability in the topography and geography of the cam morphology have been increasingly recognized. Accurate understanding and characterization of the proximal femoral deformity are important in guiding surgical correction of the cam deformity.

Advances in understanding the prevalence of the cam morphology and the association with OA have been important to our understanding of the pathophysiology of FAI. Several studies¹² have established that a cam morphology of the proximal femur (defined by a variety of different metrics) is common among asymptomatic individuals. In light of this fact, a description of the femoral anatomy as a “cam morphology” rather than a cam deformity is now favored. Similarly, FAI is better used to refer to symptomatic individuals and is not equivalent to a cam morphology. The cam morphology seems significantly more common among athletes. Siebenrock and colleagues¹³ demonstrated the correlation of high-level athletics during late stages of skeletal immaturity and development of a cam morphology. A recent systematic review of 9 studies found that elite male athletes in late skeletal immaturity were 2 to 8 times more likely to develop a cam morphology before skeletal maturity.¹⁴Several population-based studies^15,16 have quantified the apparent association of the cam morphology with hip OA. However, the studies were limited in their ability to adequately define the presence of cam morphology based on anteroposterior (AP) pelvis radiographs.

In a prospective study, Agricola and colleagues¹⁵ found the risk of OA was increased 2.4 times in the setting of moderate cam morphology (α angle, >60°) over a 5-year period. Thomas and colleagues¹⁶ found increased risk in a female cohort when the α angle was >65°.

Treatment of cam-type FAI is focused on adequate correction of the abnormal bone morphology. Inadequate or inappropriate bony correction of FAI is a common cause of treatment failure and is more common with arthroscopic techniques.^9,10,17 Inadequate bony resection may be the result of surgical inexperience, poor visualization, or lack of understanding of the underlying bony deformity. Modern osteoplasty techniques also focus on gradual bony contour correction that restores the normal concavity–convexity transition of the head–neck junction. Overresection of the cam deformity not only may increase the risk of femoral neck fracture but may result in early disruption of the hip fluid seal from loss of contact between the femoral head and the acetabular labrum earlier in the arc of motion. In addition, high range-of-motion impingement can be seen in various athletic populations (dance, gymnastics, martial arts, hockey goalies), and the regions of impingement tend to be farther away from classically described impingement. Impingement in these situations occurs at the distal femoral neck and subspine regions, adding a level of complexity and unpredictability from a surgical standpoint.

FAI can also occur in the setting of more complex deformities than the typical cam morphology. Complex cases of FAI caused by slipped capital femoral epiphysis (SCFE) and residual Legg-Calvé-Perthes disease are relatively common. Complex deformities may also result in extra-articular impingement of the proximal femur (greater/lesser trochanter, distal femoral neck) on the pelvis (ilium, ischium) in addition to typical FAI. Mild to moderate cases of residual SCFE may be adequately treated with osteoplasty by arthroscopic techniques. In the setting of more severe residual SCFE, presence of underlying femoral retroversion and retrotilt of the femoral epiphysis may prevent adequate deformity correction and motion improvement by arthroscopy. Surgical hip dislocation (with or without relative femoral neck lengthening) and/or proximal femoral flexion derotational osteotomy may be the best means of treatment in these more severe deformities but may be dependent on the chronicity of the deformity and associated compensatory changes occurring on the acetabular side. Similarly, in moderate to severe residual Legg-Calvé-Perthes disease, presence of coxa vara, high greater trochanter, short femoral neck, and ovoid femoral head may be better treated in open techniques to allow comprehensive deformity correction, including correction of acetabular dysplasia in some cases.

Pincer-Type FAI

Pincer-type FAI results from acetabular-sided deformities in which acetabular deformity leads to impaction-type impingement with “linear contact between the acetabular rim and the femoral head–neck junction.”¹ Pincer FAI causes primarily labral damage with progressive degeneration and, in some cases, ossification of the acetabular labrum that further worsens the acetabular overcoverage and premature rim impaction. Chondral damage in pincer-type FAI is generally less significant and limited to the peripheral acetabular rim.

Pincer-type FAI may be caused by acetabular retroversion, coxa profunda, or protrusio acetabuli. Our understanding of what defines a pincer morphology has evolved significantly. Through efforts to better define structural features of the acetabular rim that represent abnormalities, we have improved our understanding of how these features may influence OA development. One example of improved understanding involves coxa profunda, classically defined as the medial acetabular fossa touching or projecting medial to the ilioischial line on an AP pelvis radiograph. Several studies have found that this classic definition poorly describes the “overcovered” hip, as it is present in 70% of females and commonly present (41%) in the setting of acetabular dysplasia.^18,19 Acetabular retroversion was previously associated with hip OA. Although central acetabular retroversion is relatively uncommon, cranial acetabular retroversion is more common. Presence of a crossover sign on AP pelvis radiographs generally has been viewed as indicative of acetabular retroversion. However, alterations in pelvic tilt on supine or standing AP pelvis radiographs can result in apparent retroversion in the setting of normal acetabular anatomy²⁰ and potentially influence the development of impingement.²¹ Zaltz and colleagues²² found that abnormal morphology of the anterior inferior iliac spine can also lead to the presence of a crossover sign in an otherwise anteverted acetabulum. Larson and colleagues²³ recently found that a crossover sign is present in 11% of asymptomatic hips (19% of males) and may be considered a normal variant. A crossover sign can also be present in the setting of posterior acetabular deficiency with normal anterior acetabular coverage. Ultimately, acetabular retroversion might indicate pincer-type FAI or dysplasia or be a normal variant that does not require treatment. Global acetabular overcoverage, including coxa protrusio, may be associated with OA in population-based studies but is not uniformly demonstrated in all studies.^16,24,25 A lateral center edge angle of >40° and a Tönnis angle (acetabular inclination) of <0° are commonly viewed as markers of global overcoverage.

FAI Treatment

Improvements in hip arthroscopy techniques and instrumentation have led to hip arthroscopy becoming the primary surgical technique for the treatment of most cases of FAI. Hip arthroscopy allows for precise visualization and treatment of labral and chondral disease in the central compartment by traction. Larson and colleagues²⁶ reported complication rates for hip arthroscopy in a prospective series of >1600 cases. The overall complication rate was 8.3%, with higher rates noted in female patients and in the setting of traction time longer than 60 minutes. Nonetheless, major complications occurred in 1.1%, with only 0.1% having persistent disability. The most common complications were lateral femoral cutaneous nerve dysesthesias (1.6%), pudendal nerve neuropraxia (1.4%), and iatrogenic labral/chondral damage (2.1%).

The importance of preserving the acetabular labrum is now well accepted from clinical and biomechanical evidence.^27-29 As in previous studies in surgical hip dislocation,³⁰ arthroscopic labral repair (vs débridement) results in improved clinical outcomes.^31,32 Labral repair techniques currently focus on stable fixation of the labrum while maintaining the normal position of the labrum relative to the femoral head and avoiding labral eversion, which may compromise the hip suction seal. With continued technical advancements and biomechanical support, arthroscopic labral reconstruction is possible in the setting of labral deficiency, often resulting from prior resection. However, the optimal indications, surgical techniques, and long-term outcomes continue to be better defined. Open and arthroscopic techniques have shown similar ability to correct the typical mild to moderate cam morphology in FAI.³³ Yet, inadequate femoral bony correction of FAI seems to be the most common cause for revision hip preservation surgery.^9,10,17Mild to moderate acetabular rim deformities are commonly treated with hip arthroscopy. As our understanding of pincer-type FAI continues to improve, many surgeons are performing less- aggressive bone resection along the anterior rim. On the other hand, subspinous impingement was recently recognized as a form of extra-articular pincer FAI variant.³⁴ Subspine decompression without true acetabular rim resection has become a more common treatment for pincer lesions and may be a consideration even with restricted range of motion after periacetabular osteotomy. Severe acetabular deformities with global overcoverage or acetabular protrusion are particularly challenging by arthroscopy, even for the most experienced surgeons. Although some improvement in deformity is feasible with arthroscopy, even cases reported in the literature have demonstrated incomplete deformity correction. Open surgical hip dislocation may continue to be the ideal treatment technique for severe pincer impingement.

Cam-type FAI is commonly treated with hip arthroscopy (Figures A-F).

Conclusion

Our understanding and treatment of FAI continue to evolve. Both open and arthroscopic techniques have demonstrated excellent outcomes in the treatment of FAI. Most cases of FAI are now amenable to arthroscopic treatment. Inadequate resection and underlying acetabular dysplasia remain common causes of treatment failure. Open surgical hip dislocation continues to play a role in the treatment of severe deformities that are poorly accessible by arthroscopy—including cam lesions with posterior extension, severe global acetabular overcoverage, or extra-articular impingement. The association of FAI with OA is most apparent for cam-type FAI. Future research will define the optimal treatment strategies and determine if they modify disease progression.

Am J Orthop. 2017;46(1):28-34. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Our understanding of FAI has evolved from cam-type and pincer-type impingement to much more complex disease patterns.
• Most surgeons are performing less aggressive acetabular rim trimming.
• Inadequate osseous correction is still the most common cause of the failed hip arthroscopy.
• Labral preservation is important to maintaining suction seal effect.
• Open surgical techniques have a role for more severe and complex FAI deformities.

Femoroacetabular impingement (FAI) was described by Ganz and colleagues¹ in 2003 as a refinement of concepts introduced decades earlier. This description advanced our understanding of FAI as a mechanism for prearthritic hip pain and secondary hip osteoarthritis¹ (OA) and allowed for treatment of FAI. The concept of proximal femoral and acetabular/pelvic deformity contributing to OA had been previously speculated by Smith-Petersen,² Murray,³ Solomon,⁴ and Stulberg.⁵ Early cases of overcorrection of dysplasia using the periacetabular osteotomy created iatrogenic FAI, which further stimulated early development of the FAI concept.⁶ Improved anatomical characterization of the proximal femoral blood supply (medial femoral circumflex artery) allowed for development of the open surgical hip dislocation.⁷ Through open surgical hip dislocation, an improved understanding of hip pathomechanics by direct visualization helped pave the way for a better understanding of FAI. Open surgical hip dislocation allows for global treatment of labrochondral pathology and deformity of the proximal femoral head–neck junction and/or acetabular rim in FAI.

Hip arthroscopy has further developed and improved our understanding of FAI. Early hip arthroscopy was generally limited to débridement of labral and chondral pathology, and management of the soft-tissue structures. Advances in the understanding of FAI through open techniques allowed for application of similar techniques to hip arthroscopy. Improvements in arthroscopic instrumentation and techniques have allowed for treatment of labrochondral and acetabular-sided rim deformity in the central compartment and cam morphologies in the peripheral compartment through arthroscopic surgery. Appropriate bony correction by arthroscopic techniques has always been a concern, but improved techniques, dynamic assessment, and accurate use of intraoperative imaging have made this feasible and more predictable. Treatment of cam deformities extending adjacent and proximal to the retinacular vessels is possible but more technically demanding. Inadequate bony correction of FAI by arthroscopic means remains one of the most common causes of failure.^8-10In 2013, the Academic Network of Conservational Hip Outcome Research (ANCHOR) Study Group reported the characteristics of a FAI cohort of 1130 hips (1076 patients) that underwent surgical treatment of FAI across 8 institutions and 12 surgeons.¹¹ At that time, most ANCHOR surgeons (or surgeon groups) performed both open and arthroscopic surgeries and had significant referral volumes of complex cases that may have overrepresented the proportion of complex FAI cases in the cohort. During the 2008 to 2011 study period, FAI was treated with arthroscopy in 56% of these cases, open surgical hip dislocation in 34%, and reverse periacetabular osteotomy in 9%. FAI was characterized as isolated cam-type in 48%, combined cam–pincer type in 45%, and isolated pincer-type in 8%. Fifty-five percent of the patients were female. Patient-reported outcome studies in this cohort of patients are ongoing.

The FAI Concept

In 2003, after treating more than 600 open surgical hip dislocations over the previous decade, Ganz and colleagues¹ coined the term femoroacetabular impingement to describe a “mechanism for the development of early osteoarthritis for most nondysplastic hips.” They reported surgical treatment focused on “improving the clearance for hip motion and alleviation of femoral abutment against the acetabular rim” with the goal of improving pain and possibly of halting progression of the degenerative process. FAI was defined as “abnormal contact between the proximal femur and acetabular rim that occurs during terminal motion of the hip” leading to “lesions of the acetabular labrum and/or the adjacent acetabular cartilage.” Subtle, previously overlooked deformities of the proximal femur and acetabulum were recognized as the cause of FAI, “including the presence of a bony prominence usually in the anterolateral head and neck junction that is seen best on the lateral radiographs, reduced offset of the femoral neck and head junction, and changes on the acetabular rim such as os acetabuli or a double line that is seen with rim ossification.” Ganz and colleagues¹ recognized that “normal or near normal” hips could also experience FAI in the setting of excessive or supraphysiologic range of motion. Cam-type and pincer-type FAI deformities were introduced as 2 distinct mechanisms of FAI. By 2003, arthroscopic hip surgery was increasingly being used as a treatment for labral tears but not bony abnormalities. These FAI concepts seemed to explain the prevalence of labral tears at the anterosuperior rim, which had been noted during hip arthroscopy, and paved the way for major changes in arthroscopic hip surgery during the next decade. The ANCHOR group reported the descriptive epidemiology of a cohort of more than 1000 patients with FAI.¹¹

Cam-Type FAI

Cam-type impingement results from femoral-sided deformities. The mechanism was described as inclusion-type impingement in which “jamming of an abnormal femoral head with increasing radius into the acetabulum during forceful motion, especially flexion.”¹ This results in outside-in abrasion of the acetabular cartilage of the anterosuperior rim with detachment of the “principally uninvolved labrum”¹ and potentially delamination of the adjacent cartilage from the subchondral bone. Ganz and colleagues¹ recognized in their initial descriptions of FAI that cam-type FAI could involve decreased femoral version, femoral head–neck junction asphericity, and decreased head–neck offset. The complexity and variability in the topography and geography of the cam morphology have been increasingly recognized. Accurate understanding and characterization of the proximal femoral deformity are important in guiding surgical correction of the cam deformity.

Advances in understanding the prevalence of the cam morphology and the association with OA have been important to our understanding of the pathophysiology of FAI. Several studies¹² have established that a cam morphology of the proximal femur (defined by a variety of different metrics) is common among asymptomatic individuals. In light of this fact, a description of the femoral anatomy as a “cam morphology” rather than a cam deformity is now favored. Similarly, FAI is better used to refer to symptomatic individuals and is not equivalent to a cam morphology. The cam morphology seems significantly more common among athletes. Siebenrock and colleagues¹³ demonstrated the correlation of high-level athletics during late stages of skeletal immaturity and development of a cam morphology. A recent systematic review of 9 studies found that elite male athletes in late skeletal immaturity were 2 to 8 times more likely to develop a cam morphology before skeletal maturity.¹⁴Several population-based studies^15,16 have quantified the apparent association of the cam morphology with hip OA. However, the studies were limited in their ability to adequately define the presence of cam morphology based on anteroposterior (AP) pelvis radiographs.

In a prospective study, Agricola and colleagues¹⁵ found the risk of OA was increased 2.4 times in the setting of moderate cam morphology (α angle, >60°) over a 5-year period. Thomas and colleagues¹⁶ found increased risk in a female cohort when the α angle was >65°.

Treatment of cam-type FAI is focused on adequate correction of the abnormal bone morphology. Inadequate or inappropriate bony correction of FAI is a common cause of treatment failure and is more common with arthroscopic techniques.^9,10,17 Inadequate bony resection may be the result of surgical inexperience, poor visualization, or lack of understanding of the underlying bony deformity. Modern osteoplasty techniques also focus on gradual bony contour correction that restores the normal concavity–convexity transition of the head–neck junction. Overresection of the cam deformity not only may increase the risk of femoral neck fracture but may result in early disruption of the hip fluid seal from loss of contact between the femoral head and the acetabular labrum earlier in the arc of motion. In addition, high range-of-motion impingement can be seen in various athletic populations (dance, gymnastics, martial arts, hockey goalies), and the regions of impingement tend to be farther away from classically described impingement. Impingement in these situations occurs at the distal femoral neck and subspine regions, adding a level of complexity and unpredictability from a surgical standpoint.

FAI can also occur in the setting of more complex deformities than the typical cam morphology. Complex cases of FAI caused by slipped capital femoral epiphysis (SCFE) and residual Legg-Calvé-Perthes disease are relatively common. Complex deformities may also result in extra-articular impingement of the proximal femur (greater/lesser trochanter, distal femoral neck) on the pelvis (ilium, ischium) in addition to typical FAI. Mild to moderate cases of residual SCFE may be adequately treated with osteoplasty by arthroscopic techniques. In the setting of more severe residual SCFE, presence of underlying femoral retroversion and retrotilt of the femoral epiphysis may prevent adequate deformity correction and motion improvement by arthroscopy. Surgical hip dislocation (with or without relative femoral neck lengthening) and/or proximal femoral flexion derotational osteotomy may be the best means of treatment in these more severe deformities but may be dependent on the chronicity of the deformity and associated compensatory changes occurring on the acetabular side. Similarly, in moderate to severe residual Legg-Calvé-Perthes disease, presence of coxa vara, high greater trochanter, short femoral neck, and ovoid femoral head may be better treated in open techniques to allow comprehensive deformity correction, including correction of acetabular dysplasia in some cases.

Pincer-Type FAI

Pincer-type FAI results from acetabular-sided deformities in which acetabular deformity leads to impaction-type impingement with “linear contact between the acetabular rim and the femoral head–neck junction.”¹ Pincer FAI causes primarily labral damage with progressive degeneration and, in some cases, ossification of the acetabular labrum that further worsens the acetabular overcoverage and premature rim impaction. Chondral damage in pincer-type FAI is generally less significant and limited to the peripheral acetabular rim.

Pincer-type FAI may be caused by acetabular retroversion, coxa profunda, or protrusio acetabuli. Our understanding of what defines a pincer morphology has evolved significantly. Through efforts to better define structural features of the acetabular rim that represent abnormalities, we have improved our understanding of how these features may influence OA development. One example of improved understanding involves coxa profunda, classically defined as the medial acetabular fossa touching or projecting medial to the ilioischial line on an AP pelvis radiograph. Several studies have found that this classic definition poorly describes the “overcovered” hip, as it is present in 70% of females and commonly present (41%) in the setting of acetabular dysplasia.^18,19 Acetabular retroversion was previously associated with hip OA. Although central acetabular retroversion is relatively uncommon, cranial acetabular retroversion is more common. Presence of a crossover sign on AP pelvis radiographs generally has been viewed as indicative of acetabular retroversion. However, alterations in pelvic tilt on supine or standing AP pelvis radiographs can result in apparent retroversion in the setting of normal acetabular anatomy²⁰ and potentially influence the development of impingement.²¹ Zaltz and colleagues²² found that abnormal morphology of the anterior inferior iliac spine can also lead to the presence of a crossover sign in an otherwise anteverted acetabulum. Larson and colleagues²³ recently found that a crossover sign is present in 11% of asymptomatic hips (19% of males) and may be considered a normal variant. A crossover sign can also be present in the setting of posterior acetabular deficiency with normal anterior acetabular coverage. Ultimately, acetabular retroversion might indicate pincer-type FAI or dysplasia or be a normal variant that does not require treatment. Global acetabular overcoverage, including coxa protrusio, may be associated with OA in population-based studies but is not uniformly demonstrated in all studies.^16,24,25 A lateral center edge angle of >40° and a Tönnis angle (acetabular inclination) of <0° are commonly viewed as markers of global overcoverage.

FAI Treatment

Improvements in hip arthroscopy techniques and instrumentation have led to hip arthroscopy becoming the primary surgical technique for the treatment of most cases of FAI. Hip arthroscopy allows for precise visualization and treatment of labral and chondral disease in the central compartment by traction. Larson and colleagues²⁶ reported complication rates for hip arthroscopy in a prospective series of >1600 cases. The overall complication rate was 8.3%, with higher rates noted in female patients and in the setting of traction time longer than 60 minutes. Nonetheless, major complications occurred in 1.1%, with only 0.1% having persistent disability. The most common complications were lateral femoral cutaneous nerve dysesthesias (1.6%), pudendal nerve neuropraxia (1.4%), and iatrogenic labral/chondral damage (2.1%).

The importance of preserving the acetabular labrum is now well accepted from clinical and biomechanical evidence.^27-29 As in previous studies in surgical hip dislocation,³⁰ arthroscopic labral repair (vs débridement) results in improved clinical outcomes.^31,32 Labral repair techniques currently focus on stable fixation of the labrum while maintaining the normal position of the labrum relative to the femoral head and avoiding labral eversion, which may compromise the hip suction seal. With continued technical advancements and biomechanical support, arthroscopic labral reconstruction is possible in the setting of labral deficiency, often resulting from prior resection. However, the optimal indications, surgical techniques, and long-term outcomes continue to be better defined. Open and arthroscopic techniques have shown similar ability to correct the typical mild to moderate cam morphology in FAI.³³ Yet, inadequate femoral bony correction of FAI seems to be the most common cause for revision hip preservation surgery.^9,10,17Mild to moderate acetabular rim deformities are commonly treated with hip arthroscopy. As our understanding of pincer-type FAI continues to improve, many surgeons are performing less- aggressive bone resection along the anterior rim. On the other hand, subspinous impingement was recently recognized as a form of extra-articular pincer FAI variant.³⁴ Subspine decompression without true acetabular rim resection has become a more common treatment for pincer lesions and may be a consideration even with restricted range of motion after periacetabular osteotomy. Severe acetabular deformities with global overcoverage or acetabular protrusion are particularly challenging by arthroscopy, even for the most experienced surgeons. Although some improvement in deformity is feasible with arthroscopy, even cases reported in the literature have demonstrated incomplete deformity correction. Open surgical hip dislocation may continue to be the ideal treatment technique for severe pincer impingement.

Cam-type FAI is commonly treated with hip arthroscopy (Figures A-F).

Conclusion

Our understanding and treatment of FAI continue to evolve. Both open and arthroscopic techniques have demonstrated excellent outcomes in the treatment of FAI. Most cases of FAI are now amenable to arthroscopic treatment. Inadequate resection and underlying acetabular dysplasia remain common causes of treatment failure. Open surgical hip dislocation continues to play a role in the treatment of severe deformities that are poorly accessible by arthroscopy—including cam lesions with posterior extension, severe global acetabular overcoverage, or extra-articular impingement. The association of FAI with OA is most apparent for cam-type FAI. Future research will define the optimal treatment strategies and determine if they modify disease progression.

Am J Orthop. 2017;46(1):28-34. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• MASH is a multicenter arthroscopic study of the hip that features a large prospective database of 10 separate institutions in the United States.
• The mean patient demographic was age 34.6 years, BMI 25.9 kg/m², 62.8% females, and 97% white.
• Most patients had anterior or groin pain, but 17.6% had lateral hip pain, 13.8% had posterior hip pain, and 2.9% had low back or sacral pain.
• Patients typically had pain for about 1 year that was worsened with athletic activity as well as sitting.
• The most common surgical procedures that were performed included labral surgery in 64.7%, femoroplasty in 49.9%, acetabuloplasty in 33.3%, and chondroplasty in 31.1%

Arthroscopic surgery of the hip has been growing over the past decade, with drastically increasing rates of arthroscopic hip procedures and increased education and interest in orthopedic trainees.^1-3 The rise of this minimally invasive surgical technique may be attributed to expanding knowledge of surgical management of morphologic hip disorders as a means of hip preservation. Many arthroscopic techniques have been developed to treat intra-articular hip joint pathologies, including femoroacetabular impingement (FAI), labral tears, and cartilage damage.^4-11 These hip pathologies are widely recognized as painful limitations to activities of daily living and sports as well as early indicators of hip osteoarthritis.^12,13 Limited evidence suggests that arthroscopic treatment of these intra-articular hip joint pathologies preserves the hip from osteoarthritis and progression to total hip arthroplasty.^13-15

FAI is the most common etiology of pathologies related to arthroscopic surgery of the hip, including both labral tears and cartilage damage.^4,7,14 FAI is a morphologic bone disorder characterized by impingement of the femur and the acetabulum on flexion or rotation. The etiology of FAI is not completely understood, but evidence suggests that stress to the proximal femoral physis during skeletal growth increases the risk of developing femoral head and neck deformations leading to cam-type FAI.^15-17 Understanding the characteristics of the patient population in which FAI occurs may shed light on the processes of intra-articular damage, such as labral tears and cartilage damage.

In the present study, we collected epidemiologic data, including demographics, pathologic entities treated, patient-reported measures of disease, and surgical treatment preferences, on a hip pathology population that elected to undergo arthroscopic surgery. These data are important in gaining a better understanding of the population and environment in which hip arthroscopy is performed across multiple centers throughout the United States and may help guide clinical practice and research to advance hip arthroscopy.

Methods

The Multicenter Arthroscopic Study of the Hip (MASH) Study Group conducts multicenter clinical studies in arthroscopic hip preservation surgery. Patients are enrolled in this large prospective longitudinal study at 10 sites nationwide by 10 fellowship-trained hip arthroscopists. Institutional Review Board approval was obtained from all institutions before patient enrollment. After enrollment, we collected comprehensive patient data, including demographics, common symptoms and their duration, provocative activities, patient-reported outcome measures (modified Harris Hip Score, International Hip Outcome Tool, 12-item Short Form Health Survey, visual analog scale pain rating, Hip Outcome Score), physical examination findings, imaging findings, diagnoses, surgical findings, and surgical procedures.

All study participants were patients undergoing arthroscopic hip surgery by one of the members of the MASH Study Group. Patients with incomplete preoperative information (needed for data analysis) were excluded. Data analysis was performed with SPSS Statistics Version 21.0 (SPSS Inc.) to obtain descriptive statistics of the quantitative data and frequencies of the nominal data.

Results

Between January 2014 and November 2016, we enrolled 1738 patients (647 male, 1091 female) in the study. Table 1 lists the demographics of the population.

Regarding symptom location, 40.9% of patients described pain in the groin region, 24.2% in the anterior hip region, and 11.3% in a C-sign distribution (Table 2).

Discussion

In this study, we collected epidemiologic data (demographics, pathologic entities treated, patient-reported measures of disease, surgical treatment preferences) from a large multicenter population of hip pathology patients who elected to undergo arthroscopic surgery. Our results showed these patients were most commonly younger to middle-aged white females with pain primarily in the groin region. Most had pain for at least 1 year, and it was commonly exacerbated by sitting and athletics. Patients reported clinically significant pain and functional limitation, which showed evidence of affecting general physical and mental health. It was not uncommon for patients to have undergone another, related surgery and nonoperative treatments, including intra-articular injection and/or physical therapy, before surgery. There was a high incidence of abnormal hip morphology suggestive of a cam lesion, but the incidence of arthritic changes on radiographs was relatively low. Labral tear was the most common diagnosis, and most often it was addressed with repair. Many patients underwent femoroplasty, acetabuloplasty, and chondroplasty in addition to labral repair.

According to patient-reported outcome measures administered before surgery, 40% to 65% of patients seeking hip preservation surgery reported functional deficits and pain—which falls within the range of results from other multicenter studies on the epidemiology of FAI.^18,19 There was, however, a high amount of variability in individual scores on the functional and pain measures; some patients rated their functional ability very high. These findings were supported by the general health forms measuring global physical and mental health. Mean Physical Health and Mental Health scores on the 12-item Short Form Health Survey indicated that patients seeking hip preservation surgery thought their hip condition affected their general well-being. This finding is consistent with research on FAI,¹⁸ hip arthritis,²⁰ and total hip arthroplasty.¹⁹Our results further showed that hip arthroscopists commonly prescribed alternative treatment measures ahead of surgery. Before elective surgery, 80% of patients received an intra-articular injection, underwent physical therapy, or both. This could suggest a high failure rate for patients who chose conservative treatment approaches for hip-related pathology. However, our study was limited in that it may have included patients who had improved significantly with conservative measures and decided to forgo arthroscopic hip surgery. Although conservative treatment often is recommended in an effort to potentially avoid surgery, there is a lack of research evaluating the efficacy of nonoperative care.^21,22Analysis of diagnostic imaging and clinical examination findings revealed some unique characteristics of patients undergoing elective hip preservation surgery. MRI showed labral pathology in an overwhelming majority of these patients, but few had evidence of articular damage. Previous research has found a 67% rate of arthritic changes on diagnostic imaging, but our rate was much lower (17%).²³ Radiograph evaluation confirmed the pattern: More than 90% of our patients had Tönnis grade 0 osteoarthritis. Tönnis grade 1 or 2 osteoarthritis is a predictor of acetabular cartilage degeneration,²³ and long-term studies have related these osteoarthritic changes to poorer hip arthroscopy outcomes.²⁴ Thus, the lower incidence of osteoarthritis in our study population may reflect current evidence-based practice and a contemporary approach to patient selection.

Most of our patients had isolated cam-type FAI as opposed to pincer-type FAI or a combination of cam and pincer—contrary to research findings that combination cam–pincer FAI is most prevalent.^25,26 Our results are more consistent with more recent research findings of a higher incidence of isolated cam lesion, particularly in female patients, and combination cam–pincer in male patients.^18,27,28 Similar distributions of surgical procedures and diagnoses exist between the present study and other multicenter evaluations of the epidemiologic characteristics of patients with hip pathology.¹⁸Our study had several limitations. First, the population consisted entirely of patients who sought evaluation by a hip arthroscopy specialist and underwent elective surgery. Therefore, the data cannot be applied to a more general orthopedic population or to patients who consult other medical specialists. Second, the population, which was 97% white and had small percentages of African-American, Latino, and Asian patients, lacked ethnic diversity. This finding is consistent with recent epidemiologic research in which ethnicity was identified as a factor in patterns of hip disease.^13,29,30 Access to specialists, however, was likely affected by multiple other factors. Fourth, the validity and the reliability of the imaging modalities used have been questioned.^31-33 There is controversy regarding ideal imaging modalities for assessment of articular cartilage damage^31,32 and FAI. However, the modalities that we used to determine diagnoses in this study are well supported²⁶ and represent common practice patterns.

Am J Orthop. 2017;46(1):35-41. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• MASH is a multicenter arthroscopic study of the hip that features a large prospective database of 10 separate institutions in the United States.
• The mean patient demographic was age 34.6 years, BMI 25.9 kg/m², 62.8% females, and 97% white.
• Most patients had anterior or groin pain, but 17.6% had lateral hip pain, 13.8% had posterior hip pain, and 2.9% had low back or sacral pain.
• Patients typically had pain for about 1 year that was worsened with athletic activity as well as sitting.
• The most common surgical procedures that were performed included labral surgery in 64.7%, femoroplasty in 49.9%, acetabuloplasty in 33.3%, and chondroplasty in 31.1%

Arthroscopic surgery of the hip has been growing over the past decade, with drastically increasing rates of arthroscopic hip procedures and increased education and interest in orthopedic trainees.^1-3 The rise of this minimally invasive surgical technique may be attributed to expanding knowledge of surgical management of morphologic hip disorders as a means of hip preservation. Many arthroscopic techniques have been developed to treat intra-articular hip joint pathologies, including femoroacetabular impingement (FAI), labral tears, and cartilage damage.^4-11 These hip pathologies are widely recognized as painful limitations to activities of daily living and sports as well as early indicators of hip osteoarthritis.^12,13 Limited evidence suggests that arthroscopic treatment of these intra-articular hip joint pathologies preserves the hip from osteoarthritis and progression to total hip arthroplasty.^13-15

FAI is the most common etiology of pathologies related to arthroscopic surgery of the hip, including both labral tears and cartilage damage.^4,7,14 FAI is a morphologic bone disorder characterized by impingement of the femur and the acetabulum on flexion or rotation. The etiology of FAI is not completely understood, but evidence suggests that stress to the proximal femoral physis during skeletal growth increases the risk of developing femoral head and neck deformations leading to cam-type FAI.^15-17 Understanding the characteristics of the patient population in which FAI occurs may shed light on the processes of intra-articular damage, such as labral tears and cartilage damage.

In the present study, we collected epidemiologic data, including demographics, pathologic entities treated, patient-reported measures of disease, and surgical treatment preferences, on a hip pathology population that elected to undergo arthroscopic surgery. These data are important in gaining a better understanding of the population and environment in which hip arthroscopy is performed across multiple centers throughout the United States and may help guide clinical practice and research to advance hip arthroscopy.

Methods

The Multicenter Arthroscopic Study of the Hip (MASH) Study Group conducts multicenter clinical studies in arthroscopic hip preservation surgery. Patients are enrolled in this large prospective longitudinal study at 10 sites nationwide by 10 fellowship-trained hip arthroscopists. Institutional Review Board approval was obtained from all institutions before patient enrollment. After enrollment, we collected comprehensive patient data, including demographics, common symptoms and their duration, provocative activities, patient-reported outcome measures (modified Harris Hip Score, International Hip Outcome Tool, 12-item Short Form Health Survey, visual analog scale pain rating, Hip Outcome Score), physical examination findings, imaging findings, diagnoses, surgical findings, and surgical procedures.

All study participants were patients undergoing arthroscopic hip surgery by one of the members of the MASH Study Group. Patients with incomplete preoperative information (needed for data analysis) were excluded. Data analysis was performed with SPSS Statistics Version 21.0 (SPSS Inc.) to obtain descriptive statistics of the quantitative data and frequencies of the nominal data.

Results

Between January 2014 and November 2016, we enrolled 1738 patients (647 male, 1091 female) in the study. Table 1 lists the demographics of the population.

Regarding symptom location, 40.9% of patients described pain in the groin region, 24.2% in the anterior hip region, and 11.3% in a C-sign distribution (Table 2).

Discussion

In this study, we collected epidemiologic data (demographics, pathologic entities treated, patient-reported measures of disease, surgical treatment preferences) from a large multicenter population of hip pathology patients who elected to undergo arthroscopic surgery. Our results showed these patients were most commonly younger to middle-aged white females with pain primarily in the groin region. Most had pain for at least 1 year, and it was commonly exacerbated by sitting and athletics. Patients reported clinically significant pain and functional limitation, which showed evidence of affecting general physical and mental health. It was not uncommon for patients to have undergone another, related surgery and nonoperative treatments, including intra-articular injection and/or physical therapy, before surgery. There was a high incidence of abnormal hip morphology suggestive of a cam lesion, but the incidence of arthritic changes on radiographs was relatively low. Labral tear was the most common diagnosis, and most often it was addressed with repair. Many patients underwent femoroplasty, acetabuloplasty, and chondroplasty in addition to labral repair.

According to patient-reported outcome measures administered before surgery, 40% to 65% of patients seeking hip preservation surgery reported functional deficits and pain—which falls within the range of results from other multicenter studies on the epidemiology of FAI.^18,19 There was, however, a high amount of variability in individual scores on the functional and pain measures; some patients rated their functional ability very high. These findings were supported by the general health forms measuring global physical and mental health. Mean Physical Health and Mental Health scores on the 12-item Short Form Health Survey indicated that patients seeking hip preservation surgery thought their hip condition affected their general well-being. This finding is consistent with research on FAI,¹⁸ hip arthritis,²⁰ and total hip arthroplasty.¹⁹Our results further showed that hip arthroscopists commonly prescribed alternative treatment measures ahead of surgery. Before elective surgery, 80% of patients received an intra-articular injection, underwent physical therapy, or both. This could suggest a high failure rate for patients who chose conservative treatment approaches for hip-related pathology. However, our study was limited in that it may have included patients who had improved significantly with conservative measures and decided to forgo arthroscopic hip surgery. Although conservative treatment often is recommended in an effort to potentially avoid surgery, there is a lack of research evaluating the efficacy of nonoperative care.^21,22Analysis of diagnostic imaging and clinical examination findings revealed some unique characteristics of patients undergoing elective hip preservation surgery. MRI showed labral pathology in an overwhelming majority of these patients, but few had evidence of articular damage. Previous research has found a 67% rate of arthritic changes on diagnostic imaging, but our rate was much lower (17%).²³ Radiograph evaluation confirmed the pattern: More than 90% of our patients had Tönnis grade 0 osteoarthritis. Tönnis grade 1 or 2 osteoarthritis is a predictor of acetabular cartilage degeneration,²³ and long-term studies have related these osteoarthritic changes to poorer hip arthroscopy outcomes.²⁴ Thus, the lower incidence of osteoarthritis in our study population may reflect current evidence-based practice and a contemporary approach to patient selection.

Most of our patients had isolated cam-type FAI as opposed to pincer-type FAI or a combination of cam and pincer—contrary to research findings that combination cam–pincer FAI is most prevalent.^25,26 Our results are more consistent with more recent research findings of a higher incidence of isolated cam lesion, particularly in female patients, and combination cam–pincer in male patients.^18,27,28 Similar distributions of surgical procedures and diagnoses exist between the present study and other multicenter evaluations of the epidemiologic characteristics of patients with hip pathology.¹⁸Our study had several limitations. First, the population consisted entirely of patients who sought evaluation by a hip arthroscopy specialist and underwent elective surgery. Therefore, the data cannot be applied to a more general orthopedic population or to patients who consult other medical specialists. Second, the population, which was 97% white and had small percentages of African-American, Latino, and Asian patients, lacked ethnic diversity. This finding is consistent with recent epidemiologic research in which ethnicity was identified as a factor in patterns of hip disease.^13,29,30 Access to specialists, however, was likely affected by multiple other factors. Fourth, the validity and the reliability of the imaging modalities used have been questioned.^31-33 There is controversy regarding ideal imaging modalities for assessment of articular cartilage damage^31,32 and FAI. However, the modalities that we used to determine diagnoses in this study are well supported²⁶ and represent common practice patterns.

Am J Orthop. 2017;46(1):35-41. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• MASH is a multicenter arthroscopic study of the hip that features a large prospective database of 10 separate institutions in the United States.
• The mean patient demographic was age 34.6 years, BMI 25.9 kg/m², 62.8% females, and 97% white.
• Most patients had anterior or groin pain, but 17.6% had lateral hip pain, 13.8% had posterior hip pain, and 2.9% had low back or sacral pain.
• Patients typically had pain for about 1 year that was worsened with athletic activity as well as sitting.
• The most common surgical procedures that were performed included labral surgery in 64.7%, femoroplasty in 49.9%, acetabuloplasty in 33.3%, and chondroplasty in 31.1%

Arthroscopic surgery of the hip has been growing over the past decade, with drastically increasing rates of arthroscopic hip procedures and increased education and interest in orthopedic trainees.^1-3 The rise of this minimally invasive surgical technique may be attributed to expanding knowledge of surgical management of morphologic hip disorders as a means of hip preservation. Many arthroscopic techniques have been developed to treat intra-articular hip joint pathologies, including femoroacetabular impingement (FAI), labral tears, and cartilage damage.^4-11 These hip pathologies are widely recognized as painful limitations to activities of daily living and sports as well as early indicators of hip osteoarthritis.^12,13 Limited evidence suggests that arthroscopic treatment of these intra-articular hip joint pathologies preserves the hip from osteoarthritis and progression to total hip arthroplasty.^13-15

FAI is the most common etiology of pathologies related to arthroscopic surgery of the hip, including both labral tears and cartilage damage.^4,7,14 FAI is a morphologic bone disorder characterized by impingement of the femur and the acetabulum on flexion or rotation. The etiology of FAI is not completely understood, but evidence suggests that stress to the proximal femoral physis during skeletal growth increases the risk of developing femoral head and neck deformations leading to cam-type FAI.^15-17 Understanding the characteristics of the patient population in which FAI occurs may shed light on the processes of intra-articular damage, such as labral tears and cartilage damage.

In the present study, we collected epidemiologic data, including demographics, pathologic entities treated, patient-reported measures of disease, and surgical treatment preferences, on a hip pathology population that elected to undergo arthroscopic surgery. These data are important in gaining a better understanding of the population and environment in which hip arthroscopy is performed across multiple centers throughout the United States and may help guide clinical practice and research to advance hip arthroscopy.

Methods

The Multicenter Arthroscopic Study of the Hip (MASH) Study Group conducts multicenter clinical studies in arthroscopic hip preservation surgery. Patients are enrolled in this large prospective longitudinal study at 10 sites nationwide by 10 fellowship-trained hip arthroscopists. Institutional Review Board approval was obtained from all institutions before patient enrollment. After enrollment, we collected comprehensive patient data, including demographics, common symptoms and their duration, provocative activities, patient-reported outcome measures (modified Harris Hip Score, International Hip Outcome Tool, 12-item Short Form Health Survey, visual analog scale pain rating, Hip Outcome Score), physical examination findings, imaging findings, diagnoses, surgical findings, and surgical procedures.

All study participants were patients undergoing arthroscopic hip surgery by one of the members of the MASH Study Group. Patients with incomplete preoperative information (needed for data analysis) were excluded. Data analysis was performed with SPSS Statistics Version 21.0 (SPSS Inc.) to obtain descriptive statistics of the quantitative data and frequencies of the nominal data.

Results

Between January 2014 and November 2016, we enrolled 1738 patients (647 male, 1091 female) in the study. Table 1 lists the demographics of the population.

Regarding symptom location, 40.9% of patients described pain in the groin region, 24.2% in the anterior hip region, and 11.3% in a C-sign distribution (Table 2).

Discussion

In this study, we collected epidemiologic data (demographics, pathologic entities treated, patient-reported measures of disease, surgical treatment preferences) from a large multicenter population of hip pathology patients who elected to undergo arthroscopic surgery. Our results showed these patients were most commonly younger to middle-aged white females with pain primarily in the groin region. Most had pain for at least 1 year, and it was commonly exacerbated by sitting and athletics. Patients reported clinically significant pain and functional limitation, which showed evidence of affecting general physical and mental health. It was not uncommon for patients to have undergone another, related surgery and nonoperative treatments, including intra-articular injection and/or physical therapy, before surgery. There was a high incidence of abnormal hip morphology suggestive of a cam lesion, but the incidence of arthritic changes on radiographs was relatively low. Labral tear was the most common diagnosis, and most often it was addressed with repair. Many patients underwent femoroplasty, acetabuloplasty, and chondroplasty in addition to labral repair.

According to patient-reported outcome measures administered before surgery, 40% to 65% of patients seeking hip preservation surgery reported functional deficits and pain—which falls within the range of results from other multicenter studies on the epidemiology of FAI.^18,19 There was, however, a high amount of variability in individual scores on the functional and pain measures; some patients rated their functional ability very high. These findings were supported by the general health forms measuring global physical and mental health. Mean Physical Health and Mental Health scores on the 12-item Short Form Health Survey indicated that patients seeking hip preservation surgery thought their hip condition affected their general well-being. This finding is consistent with research on FAI,¹⁸ hip arthritis,²⁰ and total hip arthroplasty.¹⁹Our results further showed that hip arthroscopists commonly prescribed alternative treatment measures ahead of surgery. Before elective surgery, 80% of patients received an intra-articular injection, underwent physical therapy, or both. This could suggest a high failure rate for patients who chose conservative treatment approaches for hip-related pathology. However, our study was limited in that it may have included patients who had improved significantly with conservative measures and decided to forgo arthroscopic hip surgery. Although conservative treatment often is recommended in an effort to potentially avoid surgery, there is a lack of research evaluating the efficacy of nonoperative care.^21,22Analysis of diagnostic imaging and clinical examination findings revealed some unique characteristics of patients undergoing elective hip preservation surgery. MRI showed labral pathology in an overwhelming majority of these patients, but few had evidence of articular damage. Previous research has found a 67% rate of arthritic changes on diagnostic imaging, but our rate was much lower (17%).²³ Radiograph evaluation confirmed the pattern: More than 90% of our patients had Tönnis grade 0 osteoarthritis. Tönnis grade 1 or 2 osteoarthritis is a predictor of acetabular cartilage degeneration,²³ and long-term studies have related these osteoarthritic changes to poorer hip arthroscopy outcomes.²⁴ Thus, the lower incidence of osteoarthritis in our study population may reflect current evidence-based practice and a contemporary approach to patient selection.

Most of our patients had isolated cam-type FAI as opposed to pincer-type FAI or a combination of cam and pincer—contrary to research findings that combination cam–pincer FAI is most prevalent.^25,26 Our results are more consistent with more recent research findings of a higher incidence of isolated cam lesion, particularly in female patients, and combination cam–pincer in male patients.^18,27,28 Similar distributions of surgical procedures and diagnoses exist between the present study and other multicenter evaluations of the epidemiologic characteristics of patients with hip pathology.¹⁸Our study had several limitations. First, the population consisted entirely of patients who sought evaluation by a hip arthroscopy specialist and underwent elective surgery. Therefore, the data cannot be applied to a more general orthopedic population or to patients who consult other medical specialists. Second, the population, which was 97% white and had small percentages of African-American, Latino, and Asian patients, lacked ethnic diversity. This finding is consistent with recent epidemiologic research in which ethnicity was identified as a factor in patterns of hip disease.^13,29,30 Access to specialists, however, was likely affected by multiple other factors. Fourth, the validity and the reliability of the imaging modalities used have been questioned.^31-33 There is controversy regarding ideal imaging modalities for assessment of articular cartilage damage^31,32 and FAI. However, the modalities that we used to determine diagnoses in this study are well supported²⁶ and represent common practice patterns.

Am J Orthop. 2017;46(1):35-41. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Labral preservation is recommended when possible to ensure restoration of suction seal, stability, and contact pressure of the hip joint.
• Over 95% of labral tears can be addressed with primary repair.
• Consider using an accessory portal (ie, DALA) to allow for more anatomic placement of suture anchor.
• Mattress stitch when labrum >3 mm and looped stitch when labrum <3 mm.

• 10Control labral repair to avoid excessive inversion or eversion.

Arthroscopic labral repair and refixation have garnered much attention over the past several years. Restoration of suction seal and native labral function has been an evolving focus for achieving excellent results in hip preservation surgery.^1-6 Given the superior results of labral repair, including level I evidence, repair or refixation should be pursued whenever possible.⁷ Authors have reported using several labral management techniques: débridement, labralization, looped suture fixation, base stitch fixation, inversion-eversion, and reconstruction.^7-13 The optimal technique is yet to be determined. When possible, steps should be taken to repair the labrum to an anatomical position. Absolute indications for labral repair are a confirmed intra-articular diagnosis with symptomatic pain, joint space >2 mm with or without femoroacetabular impingement (FAI), labral tear or instability, and failed conservative management.^{9,11,12,14,15} More important, the surgeon must have a clear etiology of the pathologic cause of the tear and be aware of the limitations of the procedure. Labral repair is relatively contraindicated in end-stage arthritis and has failed when used alone in undiagnosed dysplasia or hip instability.¹⁶ In this article, we discuss indications for labral repair; describe Dr. Mather’s preoperative planning, labral repair technique, and postoperative care; and review published outcomes and future trends in labral repair.

Indications

At our institution, anatomical labral repair is the preferred procedure for most primary and revision hip arthroscopy procedures. We aim to restore the suction seal, re-create the contact of the labrum and the femoral head to facilitate proprioception, and restore normal stability of the labrum. Indications for primary repair are labrum width >3 mm, no more than 2 repairs, and ability to hold a suture. Our indications for reconstruction or débridement are stage 3 irreparable labral tear, calcified/cystic labrum, and multiple failed labral repairs or reconstructions. The decision to perform labral débridement or reconstruction is made on a case-by-case basis but is primarily influenced by the stability of the hip joint and the activity goals of the patient. If preoperative presentation and intraoperative examination suggest labral instability as a major component of the pathology, or if the patient wants to return to high-demand activity, we more strongly favor reconstruction over débridement. In our experience, with the technique described in this article, more than 95% of all primary labral tears can be addressed with repair.

Preoperative Planning

The goals in hip preservation surgery are to identify and address the underlying cause of the labral tear, whether it be FAI syndrome, trauma, labral instability, or all 3, and to re-create the anatomy and biomechanics of the acetabular labrum. For repair, we prefer an inversion-eversion technique with independent control of the labrum. Our initial work-up includes a thorough history and physical examination with baseline patient-reported outcome scores. Standard erect anteroposterior pelvis, Dunn lateral, and false-profile radiographs are obtained. Standard measurements of lateral center edge angle, anterior center edge angle, Tönnis angle, Tönnis grade, lateral joint space, and head extrusion indices are evaluated. Selective in-office ultrasound-guided injections are used to confirm an intra-articular source of pain. At our institution, noncontrast 3.0 Tesla magnetic resonance imaging (MRI) with volumetric interpolated breath-hold examination (VIBE) sequencing and 3-dimensional rendering is obtained for evaluation of labral and FAI morphology.¹⁷ All advanced imaging is performed without arthrogram or radiation exposure (Figures 1A-1C).

With use of the radiographs and the MRI scans, we engage the patient in an informed discussion about the labral tear, FAI, and concomitant pathology. We discuss expected outcomes of conservative or operative management given the patient’s expected functional activities, and inform the patient that primary repair is indicated for many others in similar situations. The potential for possible labral reconstruction is discussed if the patient had prior intra-articular hip surgery, has a large calcified labrum or a cystic labrum, is an athlete with failed prior surgery, or is younger than 40 years.

Labral Repair Technique

The patient is taken to the surgical suite, and a general anesthetic is administered. A peripheral nerve block is not routinely used. The patient’s feet are padded, and boots for the traction table are applied. The patient is carefully placed on a Hana table in modified supine position. Balanced traction is used to achieve proper joint distraction. The C-arm is used to verify proper distraction, assess hip stability, and achieve standard anterolateral (AL) portal placement. A midanterior portal (MAP) is created and an interportal capsulotomy is performed. Capsular suspension is performed with the InJector II Capsule Restoration System (Stryker Sports Medicine) and typically 4 or 5 high-strength No. 2 sutures (Zipline; Stryker Sports Medicine).¹⁹ Diagnostic arthroscopy is performed to identify the tear type, measure the labral width, determine the impingement area, and identify the intra-articular pathology. After the intra-articular pathology is addressed, a radiofrequency Ambient HIPVAC 50 Coblation Wand (Smith & Nephew) is used to expose the acetabular rim and subspine as indicated. Acetabuloplasty or subspine decompression is performed, and then a primary repair or refixation of the labrum is performed. We do not routinely detach the labrum for acetabular rim trimming. A crucial step here is to expose a bleeding surface to which the labrum can be repaired. If the rim is sclerotic, or the rim cannot be removed because of underlying low acetabular coverage, we prefer to obtain the bleeding surface with a microdrilling device (Stryker) that is routinely used for acetabular microfracture.

Labrum quality is used to determine which repair method to use. A hypertrophic labrum is debulked. The acetabular rim is seldom resected >3 mm, but, when it is, the newly exposed cartilage is removed. We have found that >3 mm of residual cartilage prevents refixation of the labrum directly to the bone and may interfere with anatomical positioning. When a labrum is <3 mm in width or will not hold a base technique, repair stability is the priority, and a looped method is used. A knotless anchor with No. 1 permanent suture designed for hip labral repair (CinchLock; Stryker) is our first-line anchor choice. A distal anterolateral accessory (DALA) portal is created with an outside-in technique, and anchors are drilled through this portal into zones 2 to 4 (Figures 2A-2E).

Postoperative Care

Patients are placed in a postoperative hip brace and use a continuous passive motion machine 6 hours a day for 2 weeks, and an ice machine. They maintain 30 lb of foot-flat weight-bearing for 3 weeks, and begin a standard labral repair protocol on postoperative days 3 to 7.

Discussion

Hip labral preservation has evolved over the past 10 years, and current options for labral management include excision, débridement, labralization, repair, and reconstruction.^1-13 Labral excision was studied by Miozzari and colleagues,⁸ who postulated on the basis of animal models that the labrum may regenerate. In their series of 9 patients treated with surgical hip dislocation and labral excision at average 4-year follow-up, repeat magnetic resonance angiography revealed no regeneration of tissue—modified Harris Hip Score was 83. The hip scores were less than those of patients treated with the same procedure with repair, and the authors concluded that defining labral débridement versus excision in the literature, and treating patients with primary repair or reconstruction techniques, may lead to better results. Their study used a small sample and was limited to an open procedure. Arthroscopic labral débridement in isolation was also a poor option for treatment of a labral tear. In a 2-year follow-up of 59 isolated labral débridement procedures, Krych and colleagues⁹ found 47% combined poor results.

There is level I evidence of the importance of labral repair. In 2013, Krych and colleagues⁷ conducted a randomized control trial of 38 female patients who underwent hip arthroscopy for FAI. At time of surgery, patients were randomly assigned to either débridement or repair. At 1-year follow-up, activities of daily living and Sports specific Hip Outcome Scores were statistically significantly superior in the repair group. On a subjective scale, 94% vs 78% of patients reported normal or near normal hips in the repair versus débridement groups respectively. Ayeni and colleagues²⁰ performed a systematic review of 6 studies in an attempt to develop labral management recommendations. Five of the studies (N = 490 patients total) had improved results with labral repair over reconstruction. Although the studies had a low level of evidence, they found a trend toward improved results with labral repair. These studies highlight the importance of labral preservation and proper FAI management.

Techniques for labrum repair have advanced as well—from a looped suture technique to a base stitch and knotless independent tensioning.^11-13 Restoration of the hip labrum function as a suction seal, fluid circulator and anatomic capsular repair is paramount to excellent results and stresses the importance of performing an anatomic labral repair.^1-6 Knotless anchor repair is not novel and has been previously described. Fry and Domb¹² reported on a knotless labral repair technique that uses push-lock devices (Arthrex) that do not allow for independent tensioning. Inversion-eversion was introduced to the literature by Moreira and colleagues,¹³ who described an independent tensioning technique that uses speed-lock anchors (Smith & Nephew). Our technique differs in that it involves a DALA portal; labral reduction and tensioning with a probe assist to ensure the second pass of the base stitch is at the apex of the labrum; and use of No. 1 instead of No. 2 suture. Although seemingly subtle, these differences allow for proper anchor placement nearer the rim, additional support in achieving precise suture placement, and less disruption of small labra. These differences are particularly relevant for smaller labra.

Evaluating repair techniques on the basis of high-evidence literature is challenging. In a matched-cohort study of 220 patients, Jackson and colleagues²¹ compared 2 techniques: looped and base stitch. At 2-year follow-up, patients in both groups showed improvement, and there was no statistically significant difference in patient-reported outcome measures between the groups. Sawyer and colleagues²² studied the outcomes of 326 consecutive patients who underwent looped, pierced, or combined labral repair at an average 32-month follow-up. The groups’ revision rates were comparable, each group improved in postoperative patient-reported outcomes, and the pierced group had significantly higher preoperative scores on the Western Ontario and McMaster Universities Osteoarthritis Index. These studies described a base or pierce repair that did not differ from a looped repair, though the techniques did not allow for independent tensioning to re-create an anatomical inversion-eversion repair and may have altered the reported outcomes.

Our current technique uses independent tensioning of the repair to allow control of labrum inversion-eversion to give an anatomical repair with restoration of the suction seal. Preoperative planning, addressing the FAI appropriately, proper suture-passing technique, controlling the labrum in inversion-eversion fashion, and anatomical labral repair are the elements of Dr. Mather’s preferred method for preserving the native labrum and allowing it to assume its native function.

Future Directions

As our understanding of FAI and labral function evolves, labral preservation surgery continues to advance. With surgeons continually developing new techniques and following up on previous techniques, the ability to preserve the native hip with lasting procedures evolves as well. Proper identification of the underlying cause of the labral tear and proper anatomical repair are paramount to the success of FAI surgery.

Am J Orthop. 2017;46(1):42-48. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Labral preservation is recommended when possible to ensure restoration of suction seal, stability, and contact pressure of the hip joint.
• Over 95% of labral tears can be addressed with primary repair.
• Consider using an accessory portal (ie, DALA) to allow for more anatomic placement of suture anchor.
• Mattress stitch when labrum >3 mm and looped stitch when labrum <3 mm.

• 10Control labral repair to avoid excessive inversion or eversion.

Arthroscopic labral repair and refixation have garnered much attention over the past several years. Restoration of suction seal and native labral function has been an evolving focus for achieving excellent results in hip preservation surgery.^1-6 Given the superior results of labral repair, including level I evidence, repair or refixation should be pursued whenever possible.⁷ Authors have reported using several labral management techniques: débridement, labralization, looped suture fixation, base stitch fixation, inversion-eversion, and reconstruction.^7-13 The optimal technique is yet to be determined. When possible, steps should be taken to repair the labrum to an anatomical position. Absolute indications for labral repair are a confirmed intra-articular diagnosis with symptomatic pain, joint space >2 mm with or without femoroacetabular impingement (FAI), labral tear or instability, and failed conservative management.^{9,11,12,14,15} More important, the surgeon must have a clear etiology of the pathologic cause of the tear and be aware of the limitations of the procedure. Labral repair is relatively contraindicated in end-stage arthritis and has failed when used alone in undiagnosed dysplasia or hip instability.¹⁶ In this article, we discuss indications for labral repair; describe Dr. Mather’s preoperative planning, labral repair technique, and postoperative care; and review published outcomes and future trends in labral repair.

Indications

At our institution, anatomical labral repair is the preferred procedure for most primary and revision hip arthroscopy procedures. We aim to restore the suction seal, re-create the contact of the labrum and the femoral head to facilitate proprioception, and restore normal stability of the labrum. Indications for primary repair are labrum width >3 mm, no more than 2 repairs, and ability to hold a suture. Our indications for reconstruction or débridement are stage 3 irreparable labral tear, calcified/cystic labrum, and multiple failed labral repairs or reconstructions. The decision to perform labral débridement or reconstruction is made on a case-by-case basis but is primarily influenced by the stability of the hip joint and the activity goals of the patient. If preoperative presentation and intraoperative examination suggest labral instability as a major component of the pathology, or if the patient wants to return to high-demand activity, we more strongly favor reconstruction over débridement. In our experience, with the technique described in this article, more than 95% of all primary labral tears can be addressed with repair.

Preoperative Planning

The goals in hip preservation surgery are to identify and address the underlying cause of the labral tear, whether it be FAI syndrome, trauma, labral instability, or all 3, and to re-create the anatomy and biomechanics of the acetabular labrum. For repair, we prefer an inversion-eversion technique with independent control of the labrum. Our initial work-up includes a thorough history and physical examination with baseline patient-reported outcome scores. Standard erect anteroposterior pelvis, Dunn lateral, and false-profile radiographs are obtained. Standard measurements of lateral center edge angle, anterior center edge angle, Tönnis angle, Tönnis grade, lateral joint space, and head extrusion indices are evaluated. Selective in-office ultrasound-guided injections are used to confirm an intra-articular source of pain. At our institution, noncontrast 3.0 Tesla magnetic resonance imaging (MRI) with volumetric interpolated breath-hold examination (VIBE) sequencing and 3-dimensional rendering is obtained for evaluation of labral and FAI morphology.¹⁷ All advanced imaging is performed without arthrogram or radiation exposure (Figures 1A-1C).

With use of the radiographs and the MRI scans, we engage the patient in an informed discussion about the labral tear, FAI, and concomitant pathology. We discuss expected outcomes of conservative or operative management given the patient’s expected functional activities, and inform the patient that primary repair is indicated for many others in similar situations. The potential for possible labral reconstruction is discussed if the patient had prior intra-articular hip surgery, has a large calcified labrum or a cystic labrum, is an athlete with failed prior surgery, or is younger than 40 years.

Labral Repair Technique

The patient is taken to the surgical suite, and a general anesthetic is administered. A peripheral nerve block is not routinely used. The patient’s feet are padded, and boots for the traction table are applied. The patient is carefully placed on a Hana table in modified supine position. Balanced traction is used to achieve proper joint distraction. The C-arm is used to verify proper distraction, assess hip stability, and achieve standard anterolateral (AL) portal placement. A midanterior portal (MAP) is created and an interportal capsulotomy is performed. Capsular suspension is performed with the InJector II Capsule Restoration System (Stryker Sports Medicine) and typically 4 or 5 high-strength No. 2 sutures (Zipline; Stryker Sports Medicine).¹⁹ Diagnostic arthroscopy is performed to identify the tear type, measure the labral width, determine the impingement area, and identify the intra-articular pathology. After the intra-articular pathology is addressed, a radiofrequency Ambient HIPVAC 50 Coblation Wand (Smith & Nephew) is used to expose the acetabular rim and subspine as indicated. Acetabuloplasty or subspine decompression is performed, and then a primary repair or refixation of the labrum is performed. We do not routinely detach the labrum for acetabular rim trimming. A crucial step here is to expose a bleeding surface to which the labrum can be repaired. If the rim is sclerotic, or the rim cannot be removed because of underlying low acetabular coverage, we prefer to obtain the bleeding surface with a microdrilling device (Stryker) that is routinely used for acetabular microfracture.

Labrum quality is used to determine which repair method to use. A hypertrophic labrum is debulked. The acetabular rim is seldom resected >3 mm, but, when it is, the newly exposed cartilage is removed. We have found that >3 mm of residual cartilage prevents refixation of the labrum directly to the bone and may interfere with anatomical positioning. When a labrum is <3 mm in width or will not hold a base technique, repair stability is the priority, and a looped method is used. A knotless anchor with No. 1 permanent suture designed for hip labral repair (CinchLock; Stryker) is our first-line anchor choice. A distal anterolateral accessory (DALA) portal is created with an outside-in technique, and anchors are drilled through this portal into zones 2 to 4 (Figures 2A-2E).

Postoperative Care

Patients are placed in a postoperative hip brace and use a continuous passive motion machine 6 hours a day for 2 weeks, and an ice machine. They maintain 30 lb of foot-flat weight-bearing for 3 weeks, and begin a standard labral repair protocol on postoperative days 3 to 7.

Discussion

Hip labral preservation has evolved over the past 10 years, and current options for labral management include excision, débridement, labralization, repair, and reconstruction.^1-13 Labral excision was studied by Miozzari and colleagues,⁸ who postulated on the basis of animal models that the labrum may regenerate. In their series of 9 patients treated with surgical hip dislocation and labral excision at average 4-year follow-up, repeat magnetic resonance angiography revealed no regeneration of tissue—modified Harris Hip Score was 83. The hip scores were less than those of patients treated with the same procedure with repair, and the authors concluded that defining labral débridement versus excision in the literature, and treating patients with primary repair or reconstruction techniques, may lead to better results. Their study used a small sample and was limited to an open procedure. Arthroscopic labral débridement in isolation was also a poor option for treatment of a labral tear. In a 2-year follow-up of 59 isolated labral débridement procedures, Krych and colleagues⁹ found 47% combined poor results.

There is level I evidence of the importance of labral repair. In 2013, Krych and colleagues⁷ conducted a randomized control trial of 38 female patients who underwent hip arthroscopy for FAI. At time of surgery, patients were randomly assigned to either débridement or repair. At 1-year follow-up, activities of daily living and Sports specific Hip Outcome Scores were statistically significantly superior in the repair group. On a subjective scale, 94% vs 78% of patients reported normal or near normal hips in the repair versus débridement groups respectively. Ayeni and colleagues²⁰ performed a systematic review of 6 studies in an attempt to develop labral management recommendations. Five of the studies (N = 490 patients total) had improved results with labral repair over reconstruction. Although the studies had a low level of evidence, they found a trend toward improved results with labral repair. These studies highlight the importance of labral preservation and proper FAI management.

Techniques for labrum repair have advanced as well—from a looped suture technique to a base stitch and knotless independent tensioning.^11-13 Restoration of the hip labrum function as a suction seal, fluid circulator and anatomic capsular repair is paramount to excellent results and stresses the importance of performing an anatomic labral repair.^1-6 Knotless anchor repair is not novel and has been previously described. Fry and Domb¹² reported on a knotless labral repair technique that uses push-lock devices (Arthrex) that do not allow for independent tensioning. Inversion-eversion was introduced to the literature by Moreira and colleagues,¹³ who described an independent tensioning technique that uses speed-lock anchors (Smith & Nephew). Our technique differs in that it involves a DALA portal; labral reduction and tensioning with a probe assist to ensure the second pass of the base stitch is at the apex of the labrum; and use of No. 1 instead of No. 2 suture. Although seemingly subtle, these differences allow for proper anchor placement nearer the rim, additional support in achieving precise suture placement, and less disruption of small labra. These differences are particularly relevant for smaller labra.

Evaluating repair techniques on the basis of high-evidence literature is challenging. In a matched-cohort study of 220 patients, Jackson and colleagues²¹ compared 2 techniques: looped and base stitch. At 2-year follow-up, patients in both groups showed improvement, and there was no statistically significant difference in patient-reported outcome measures between the groups. Sawyer and colleagues²² studied the outcomes of 326 consecutive patients who underwent looped, pierced, or combined labral repair at an average 32-month follow-up. The groups’ revision rates were comparable, each group improved in postoperative patient-reported outcomes, and the pierced group had significantly higher preoperative scores on the Western Ontario and McMaster Universities Osteoarthritis Index. These studies described a base or pierce repair that did not differ from a looped repair, though the techniques did not allow for independent tensioning to re-create an anatomical inversion-eversion repair and may have altered the reported outcomes.

Our current technique uses independent tensioning of the repair to allow control of labrum inversion-eversion to give an anatomical repair with restoration of the suction seal. Preoperative planning, addressing the FAI appropriately, proper suture-passing technique, controlling the labrum in inversion-eversion fashion, and anatomical labral repair are the elements of Dr. Mather’s preferred method for preserving the native labrum and allowing it to assume its native function.

Future Directions

As our understanding of FAI and labral function evolves, labral preservation surgery continues to advance. With surgeons continually developing new techniques and following up on previous techniques, the ability to preserve the native hip with lasting procedures evolves as well. Proper identification of the underlying cause of the labral tear and proper anatomical repair are paramount to the success of FAI surgery.

Am J Orthop. 2017;46(1):42-48. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Labral preservation is recommended when possible to ensure restoration of suction seal, stability, and contact pressure of the hip joint.
• Over 95% of labral tears can be addressed with primary repair.
• Consider using an accessory portal (ie, DALA) to allow for more anatomic placement of suture anchor.
• Mattress stitch when labrum >3 mm and looped stitch when labrum <3 mm.

• 10Control labral repair to avoid excessive inversion or eversion.

Arthroscopic labral repair and refixation have garnered much attention over the past several years. Restoration of suction seal and native labral function has been an evolving focus for achieving excellent results in hip preservation surgery.^1-6 Given the superior results of labral repair, including level I evidence, repair or refixation should be pursued whenever possible.⁷ Authors have reported using several labral management techniques: débridement, labralization, looped suture fixation, base stitch fixation, inversion-eversion, and reconstruction.^7-13 The optimal technique is yet to be determined. When possible, steps should be taken to repair the labrum to an anatomical position. Absolute indications for labral repair are a confirmed intra-articular diagnosis with symptomatic pain, joint space >2 mm with or without femoroacetabular impingement (FAI), labral tear or instability, and failed conservative management.^{9,11,12,14,15} More important, the surgeon must have a clear etiology of the pathologic cause of the tear and be aware of the limitations of the procedure. Labral repair is relatively contraindicated in end-stage arthritis and has failed when used alone in undiagnosed dysplasia or hip instability.¹⁶ In this article, we discuss indications for labral repair; describe Dr. Mather’s preoperative planning, labral repair technique, and postoperative care; and review published outcomes and future trends in labral repair.

Indications

At our institution, anatomical labral repair is the preferred procedure for most primary and revision hip arthroscopy procedures. We aim to restore the suction seal, re-create the contact of the labrum and the femoral head to facilitate proprioception, and restore normal stability of the labrum. Indications for primary repair are labrum width >3 mm, no more than 2 repairs, and ability to hold a suture. Our indications for reconstruction or débridement are stage 3 irreparable labral tear, calcified/cystic labrum, and multiple failed labral repairs or reconstructions. The decision to perform labral débridement or reconstruction is made on a case-by-case basis but is primarily influenced by the stability of the hip joint and the activity goals of the patient. If preoperative presentation and intraoperative examination suggest labral instability as a major component of the pathology, or if the patient wants to return to high-demand activity, we more strongly favor reconstruction over débridement. In our experience, with the technique described in this article, more than 95% of all primary labral tears can be addressed with repair.

Preoperative Planning

The goals in hip preservation surgery are to identify and address the underlying cause of the labral tear, whether it be FAI syndrome, trauma, labral instability, or all 3, and to re-create the anatomy and biomechanics of the acetabular labrum. For repair, we prefer an inversion-eversion technique with independent control of the labrum. Our initial work-up includes a thorough history and physical examination with baseline patient-reported outcome scores. Standard erect anteroposterior pelvis, Dunn lateral, and false-profile radiographs are obtained. Standard measurements of lateral center edge angle, anterior center edge angle, Tönnis angle, Tönnis grade, lateral joint space, and head extrusion indices are evaluated. Selective in-office ultrasound-guided injections are used to confirm an intra-articular source of pain. At our institution, noncontrast 3.0 Tesla magnetic resonance imaging (MRI) with volumetric interpolated breath-hold examination (VIBE) sequencing and 3-dimensional rendering is obtained for evaluation of labral and FAI morphology.¹⁷ All advanced imaging is performed without arthrogram or radiation exposure (Figures 1A-1C).

With use of the radiographs and the MRI scans, we engage the patient in an informed discussion about the labral tear, FAI, and concomitant pathology. We discuss expected outcomes of conservative or operative management given the patient’s expected functional activities, and inform the patient that primary repair is indicated for many others in similar situations. The potential for possible labral reconstruction is discussed if the patient had prior intra-articular hip surgery, has a large calcified labrum or a cystic labrum, is an athlete with failed prior surgery, or is younger than 40 years.

Labral Repair Technique

The patient is taken to the surgical suite, and a general anesthetic is administered. A peripheral nerve block is not routinely used. The patient’s feet are padded, and boots for the traction table are applied. The patient is carefully placed on a Hana table in modified supine position. Balanced traction is used to achieve proper joint distraction. The C-arm is used to verify proper distraction, assess hip stability, and achieve standard anterolateral (AL) portal placement. A midanterior portal (MAP) is created and an interportal capsulotomy is performed. Capsular suspension is performed with the InJector II Capsule Restoration System (Stryker Sports Medicine) and typically 4 or 5 high-strength No. 2 sutures (Zipline; Stryker Sports Medicine).¹⁹ Diagnostic arthroscopy is performed to identify the tear type, measure the labral width, determine the impingement area, and identify the intra-articular pathology. After the intra-articular pathology is addressed, a radiofrequency Ambient HIPVAC 50 Coblation Wand (Smith & Nephew) is used to expose the acetabular rim and subspine as indicated. Acetabuloplasty or subspine decompression is performed, and then a primary repair or refixation of the labrum is performed. We do not routinely detach the labrum for acetabular rim trimming. A crucial step here is to expose a bleeding surface to which the labrum can be repaired. If the rim is sclerotic, or the rim cannot be removed because of underlying low acetabular coverage, we prefer to obtain the bleeding surface with a microdrilling device (Stryker) that is routinely used for acetabular microfracture.

Labrum quality is used to determine which repair method to use. A hypertrophic labrum is debulked. The acetabular rim is seldom resected >3 mm, but, when it is, the newly exposed cartilage is removed. We have found that >3 mm of residual cartilage prevents refixation of the labrum directly to the bone and may interfere with anatomical positioning. When a labrum is <3 mm in width or will not hold a base technique, repair stability is the priority, and a looped method is used. A knotless anchor with No. 1 permanent suture designed for hip labral repair (CinchLock; Stryker) is our first-line anchor choice. A distal anterolateral accessory (DALA) portal is created with an outside-in technique, and anchors are drilled through this portal into zones 2 to 4 (Figures 2A-2E).

Postoperative Care

Patients are placed in a postoperative hip brace and use a continuous passive motion machine 6 hours a day for 2 weeks, and an ice machine. They maintain 30 lb of foot-flat weight-bearing for 3 weeks, and begin a standard labral repair protocol on postoperative days 3 to 7.

Discussion

Hip labral preservation has evolved over the past 10 years, and current options for labral management include excision, débridement, labralization, repair, and reconstruction.^1-13 Labral excision was studied by Miozzari and colleagues,⁸ who postulated on the basis of animal models that the labrum may regenerate. In their series of 9 patients treated with surgical hip dislocation and labral excision at average 4-year follow-up, repeat magnetic resonance angiography revealed no regeneration of tissue—modified Harris Hip Score was 83. The hip scores were less than those of patients treated with the same procedure with repair, and the authors concluded that defining labral débridement versus excision in the literature, and treating patients with primary repair or reconstruction techniques, may lead to better results. Their study used a small sample and was limited to an open procedure. Arthroscopic labral débridement in isolation was also a poor option for treatment of a labral tear. In a 2-year follow-up of 59 isolated labral débridement procedures, Krych and colleagues⁹ found 47% combined poor results.

There is level I evidence of the importance of labral repair. In 2013, Krych and colleagues⁷ conducted a randomized control trial of 38 female patients who underwent hip arthroscopy for FAI. At time of surgery, patients were randomly assigned to either débridement or repair. At 1-year follow-up, activities of daily living and Sports specific Hip Outcome Scores were statistically significantly superior in the repair group. On a subjective scale, 94% vs 78% of patients reported normal or near normal hips in the repair versus débridement groups respectively. Ayeni and colleagues²⁰ performed a systematic review of 6 studies in an attempt to develop labral management recommendations. Five of the studies (N = 490 patients total) had improved results with labral repair over reconstruction. Although the studies had a low level of evidence, they found a trend toward improved results with labral repair. These studies highlight the importance of labral preservation and proper FAI management.

Techniques for labrum repair have advanced as well—from a looped suture technique to a base stitch and knotless independent tensioning.^11-13 Restoration of the hip labrum function as a suction seal, fluid circulator and anatomic capsular repair is paramount to excellent results and stresses the importance of performing an anatomic labral repair.^1-6 Knotless anchor repair is not novel and has been previously described. Fry and Domb¹² reported on a knotless labral repair technique that uses push-lock devices (Arthrex) that do not allow for independent tensioning. Inversion-eversion was introduced to the literature by Moreira and colleagues,¹³ who described an independent tensioning technique that uses speed-lock anchors (Smith & Nephew). Our technique differs in that it involves a DALA portal; labral reduction and tensioning with a probe assist to ensure the second pass of the base stitch is at the apex of the labrum; and use of No. 1 instead of No. 2 suture. Although seemingly subtle, these differences allow for proper anchor placement nearer the rim, additional support in achieving precise suture placement, and less disruption of small labra. These differences are particularly relevant for smaller labra.

Evaluating repair techniques on the basis of high-evidence literature is challenging. In a matched-cohort study of 220 patients, Jackson and colleagues²¹ compared 2 techniques: looped and base stitch. At 2-year follow-up, patients in both groups showed improvement, and there was no statistically significant difference in patient-reported outcome measures between the groups. Sawyer and colleagues²² studied the outcomes of 326 consecutive patients who underwent looped, pierced, or combined labral repair at an average 32-month follow-up. The groups’ revision rates were comparable, each group improved in postoperative patient-reported outcomes, and the pierced group had significantly higher preoperative scores on the Western Ontario and McMaster Universities Osteoarthritis Index. These studies described a base or pierce repair that did not differ from a looped repair, though the techniques did not allow for independent tensioning to re-create an anatomical inversion-eversion repair and may have altered the reported outcomes.

Our current technique uses independent tensioning of the repair to allow control of labrum inversion-eversion to give an anatomical repair with restoration of the suction seal. Preoperative planning, addressing the FAI appropriately, proper suture-passing technique, controlling the labrum in inversion-eversion fashion, and anatomical labral repair are the elements of Dr. Mather’s preferred method for preserving the native labrum and allowing it to assume its native function.

Future Directions

As our understanding of FAI and labral function evolves, labral preservation surgery continues to advance. With surgeons continually developing new techniques and following up on previous techniques, the ability to preserve the native hip with lasting procedures evolves as well. Proper identification of the underlying cause of the labral tear and proper anatomical repair are paramount to the success of FAI surgery.

Am J Orthop. 2017;46(1):42-48. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Hip capsule provides static stabilization for the hip joint.
• Capsular management must weigh visualization to address underlying osseous deformity but also repair/plication of the capsule to maintain biomechanical characteristics.
• T-capsulotomy provides optimal visualization with a small interportal incision with a vertical incision along the femoral neck.
• Extensile interportal capsulotomy is the most widely used capsulotomy and size may vary depending on capsular and patient characteristics.
• Orthopedic surgeons should be equipped to employ either technique depending on the patients individual hip pathomorphology.

Hip arthroscopy has emerged as a common surgical treatment for a number of hip pathologies. Surgical treatment strategies, including management of the hip capsule, have evolved. Whereas earlier hip arthroscopies often involved capsulectomy or capsulotomy without repair, more recently capsular closure has been considered an important step in restoring the anatomy of the hip joint and preventing microinstability or gross macroinstability.

The anatomy of the hip joint includes both static and dynamic stabilizers designed to maintain a functioning articulation. The osseous articulation of the femoral head and acetabulum is the first static stabilizer, with variations in offset, version, and inclination of the acetabulum and the proximal femur. The joint capsule consists of 3 ligaments—iliofemoral, pubofemoral, and ischiofemoral—that converge to form the zona orbicularis. Other soft-tissue structures, such as the articular cartilage, the labrum, the transverse acetabular ligament, the pulvinar, and the ligamentum teres, also provide static constraint.¹ The surrounding musculature provides the hip joint with dynamic stability, which contributes to overall maintenance of proper joint kinematics.

Management of the hip capsule has evolved as our understanding of hip pathology and biomechanics has matured. Initial articles on using hip arthroscopy to treat labral tears described improvement in clinical outcomes,² but the cases involved limited focal capsulotomy. Not until the idea of femoroacetabular impingement (FAI) was introduced were extensive capsulotomies and capsulectomies performed to address the underlying osseous deformities and emulate open techniques. Soon after our ability to access osseous pathomorphology improved with enhanced visualization and comprehensive resection, cases of hip instability after hip arthroscopy surfaced.^3-5 Although frank dislocation after hip arthroscopy is rare and largely underreported, it is a catastrophic complication. In addition, focal capsular defects were also described in cases of failed hip arthroscopy and thought to lead to microinstability of the hip.⁶ Iatrogenic microinstability is thought to be more common, but it is also underrecognized as a cause of failure of hip arthroscopy.⁷Microinstability is a pathologic condition that can affect hip function. In cases of recurrent pain and unimproved functional status after surgery, microinstability should be considered. In an imaging study of capsule integrity, McCormick and colleagues⁶ found that 78% of patients who underwent revision arthroscopic surgery after hip arthroscopic surgery for FAI showed evidence of capsular and iliofemoral defects on magnetic resonance angiography. Frank and colleagues⁸ reported that, though all patients showed preoperative-to-postoperative improvement on outcome measures, those who underwent complete repair of their T-capsulotomy (vs repair of only its longitudinal portion) had superior outcomes, particularly increased sport-specific activity.

For patients undergoing hip arthroscopy, several predisposing factors can increase the risk of postoperative instability. Patient-related hip instability factors include generalized ligamentous laxity, supraphysiologic athletics (eg, dance), and borderline or true hip dysplasia. Surgeon-related factors include overaggressive acetabular rim resection, excessive labral débridement, and lack of capsular repair.^5,9 Although there are multiple techniques for accessing the hip joint and addressing capsular closure at the end of surgery,^9-14 we think capsular closure is an important aspect of the case.

Surgical Technique

For a demonstration of this technique, click here to see the video that accompanies this article. The patient is moved to a traction table and placed in the supine position. Induction of general anesthesia with muscle relaxation allows for atraumatic axial traction. The anesthetized patient is assessed for passive motion and ligamentous laxity. Well-padded boots are applied, and a well-padded perineal post is used for positioning. Gentle traction is applied to the contralateral limb, and axial traction is applied through the surgical limb with the hip abducted and minimally flexed. The leg is then adducted and neutrally extended, inducing a transverse vector cantilever moment to the proximal femur. The foot is internally rotated to optimize femoral neck length on an anteroposterior radiograph. The circulating nursing staff notes the onset of hip distraction in order to ensure safe traction duration.

Bony landmarks are marked with a sterile marking pen. Under fluoroscopic guidance, an anterolateral (AL) portal is established 1 cm proximal and 1 cm anterior to the AL tip of the greater trochanter. Standard cannulation allows for intra-articular visualization with a 70° arthroscope. A needle is used to localize placement of a modified anterior portal. After cannulation, the arthroscope is placed in the modified anterior portal to confirm safe entry of the portal without labral violation. An arthroscopic scalpel (Samurai Blade; Stryker Sports Medicine) is used to make a transverse interportal capsulotomy 8 mm to 10 mm from the labrum and extending from 12 to 2 o’clock; length is 2 cm to 4 cm, depending on the extent of the intra-articular injury (Figure 1A).

T-Capsulotomy

Pericapsular fatty tissue is débrided with an arthroscopic shaver to visualize the interval between the iliocapsularis and gluteus minimus muscles. An arthroscopic scalpel is used, through a 5.0-mm cannula in the DALA portal, to extend the capsulotomy longitudinally and perpendicular to the interportal capsulotomy (Figure 1C). The T-capsulotomy is performed along the length of the femoral neck distally to the capsular reflection at the intertrochanteric line. The arthroscopic burr is used to perform a femoral osteochondroplasty between the lateral synovial folds (12 o’clock) and the medial synovial folds (6 o’clock). Dynamic examination and fluoroscopic imaging confirm that the entire cam deformity has been excised and that there is no evidence of impingement.

Although various suture-shuttling or tissue-penetrating/retrieving devices may be used, we recommend whichever device is appropriate for closing the capsule in its entirety. With the arthroscope in the modified anterior portal, an 8.25-mm × 90-mm cannula is placed in the AL portal, and an 8.25-mm × 110-mm cannula in the DALA portal. These portals will facilitate suture passage.

The vertical limb of the T-capsulotomy is closed with 2 to 4 side-to-side sutures, and the interportal capsulotomy limb with 2 or 3 sutures. Capsular closure begins with the distal portion of the longitudinal limb at the base of the iliofemoral ligament (IFL). A crescent tissue penetrating device (Slingshot; Stryker Sports Medicine) is loaded with high-strength No. 2 suture (Zipline; Stryker Sports Medicine) and placed through the AL portal to sharply pierce the lateral leaflet of the IFL (Figure 1D). The No. 2 suture is shuttled into the intra-articular side of the capsule (Figure 1E). Through the DALA portal, the penetrating device is used to pierce the medial leaflet to retrieve the free suture (Figure 1F). Next, the looped suture retriever is used to pull the suture from the AL portal to the DALA portal so the suture can be tied. We prefer to tie each suture individually after it is passed, but all of the sutures can be passed first, and then tied. As successive suture placement and knot tying inherently tighten the capsule, successive visualization requires more precision. Each subsequent suture is similarly passed, about 1 cm proximal to the previous stitch.

After closure of the vertical limb of the T-capsulotomy, we prefer to close the interportal capsulotomy with the InJector II Capsule Restoration System (Stryker Sports Medicine), a device that allows for closure through a single cannula lateral to medial. This device is passed through the AL cannula in order to bring the suture end through the proximal IFL attached to the acetabulum (Figure 1G). The device is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL (Figure 1H). The stitch is then tensioned and tied. Likewise, closure of the medial IFL involves passing the InJector through the DALA cannula and bringing the first suture end through the proximal IFL attached to the acetabulum. The Injector is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL. The stitch is then tensioned and tied with the hip in neutral extension. Generally, 2 or 3 stitches are used to close the interportal capsulotomy. Complete capsular closure is confirmed by the inability to visualize the underlying femoral head/neck and by probing the anterior capsule to ensure proper tension (Figure 1I).

Extensile Interportal Capsulotomy

An alternative to T-capsulotomy is interportal capsulotomy. Just as with T-capsulotomy closure, multiple different suture passing devices can be used. Good visualization for accessing the peripheral compartment generally is achieved by making the interportal capsulotomy 4 cm to 6 cm longer than the horizontal limb of the T-capsulotomy (Figures 2A, 2B). Capsular closure usually begins with the medial portion of the interportal capsulotomy. With the arthroscope in the AL portal, the 8.25-mm × 90-mm cannula is placed in the midanterior portal (MAP), and an 8.25-mm × 110-mm cannula is placed in the DALA portal.

Ligamentous laxity determines degree of capsular closure. The capsular leaflets can be closed end to end if there is little concern for laxity and instability. If there is more concern for capsular laxity, a larger bite of the capsular tissue can be taken to allow for a greater degree of plication. Further, the interportal capsule can be tightened by alternately advancing the location where sutures are passed through the capsule. Specifically, the sutures are passed such that larger bites of the distal capsule are taken, increasing the tightness of the capsule in external rotation.⁹

Rehabilitation

After surgery, hip extension and external rotation are limited to decrease stress on the capsular closure. The patient is placed into a hip orthosis with 0° to 90° of flexion and a night abduction pillow to limit hip external rotation. Crutch-assisted gait with 20 lb of foot-flat weight-bearing is maintained the first 3 weeks. Continuous passive motion and use of a stationary bicycle are recommended for the first 3 weeks, and then the patient slowly progresses to muscle strengthening, including core and proximal motor control. Closed-chain exercises are begun 6 weeks after surgery. Treadmill running may start at 12 weeks, with the goal of returning to sport at 4 to 6 months.

Discussion

Capsular closure during hip arthroscopy restores the normal anatomy of the IFL and therefore restores the biomechanical characteristics of the hip joint. Scientific studies have found that capsular repair or plication after hip arthroscopy restores normal hip translation, rotation, and strain. Clinical studies have also demonstrated a lower revision rate and more rapid return to athletic activity. Capsular closure, however, is technically challenging and increases operative time, but gross instability and microinstability can be avoided with meticulous closure/plication.

Am J Orthop. 2017;46(1):49-54. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Hip capsule provides static stabilization for the hip joint.
• Capsular management must weigh visualization to address underlying osseous deformity but also repair/plication of the capsule to maintain biomechanical characteristics.
• T-capsulotomy provides optimal visualization with a small interportal incision with a vertical incision along the femoral neck.
• Extensile interportal capsulotomy is the most widely used capsulotomy and size may vary depending on capsular and patient characteristics.
• Orthopedic surgeons should be equipped to employ either technique depending on the patients individual hip pathomorphology.

Hip arthroscopy has emerged as a common surgical treatment for a number of hip pathologies. Surgical treatment strategies, including management of the hip capsule, have evolved. Whereas earlier hip arthroscopies often involved capsulectomy or capsulotomy without repair, more recently capsular closure has been considered an important step in restoring the anatomy of the hip joint and preventing microinstability or gross macroinstability.

The anatomy of the hip joint includes both static and dynamic stabilizers designed to maintain a functioning articulation. The osseous articulation of the femoral head and acetabulum is the first static stabilizer, with variations in offset, version, and inclination of the acetabulum and the proximal femur. The joint capsule consists of 3 ligaments—iliofemoral, pubofemoral, and ischiofemoral—that converge to form the zona orbicularis. Other soft-tissue structures, such as the articular cartilage, the labrum, the transverse acetabular ligament, the pulvinar, and the ligamentum teres, also provide static constraint.¹ The surrounding musculature provides the hip joint with dynamic stability, which contributes to overall maintenance of proper joint kinematics.

Management of the hip capsule has evolved as our understanding of hip pathology and biomechanics has matured. Initial articles on using hip arthroscopy to treat labral tears described improvement in clinical outcomes,² but the cases involved limited focal capsulotomy. Not until the idea of femoroacetabular impingement (FAI) was introduced were extensive capsulotomies and capsulectomies performed to address the underlying osseous deformities and emulate open techniques. Soon after our ability to access osseous pathomorphology improved with enhanced visualization and comprehensive resection, cases of hip instability after hip arthroscopy surfaced.^3-5 Although frank dislocation after hip arthroscopy is rare and largely underreported, it is a catastrophic complication. In addition, focal capsular defects were also described in cases of failed hip arthroscopy and thought to lead to microinstability of the hip.⁶ Iatrogenic microinstability is thought to be more common, but it is also underrecognized as a cause of failure of hip arthroscopy.⁷Microinstability is a pathologic condition that can affect hip function. In cases of recurrent pain and unimproved functional status after surgery, microinstability should be considered. In an imaging study of capsule integrity, McCormick and colleagues⁶ found that 78% of patients who underwent revision arthroscopic surgery after hip arthroscopic surgery for FAI showed evidence of capsular and iliofemoral defects on magnetic resonance angiography. Frank and colleagues⁸ reported that, though all patients showed preoperative-to-postoperative improvement on outcome measures, those who underwent complete repair of their T-capsulotomy (vs repair of only its longitudinal portion) had superior outcomes, particularly increased sport-specific activity.

For patients undergoing hip arthroscopy, several predisposing factors can increase the risk of postoperative instability. Patient-related hip instability factors include generalized ligamentous laxity, supraphysiologic athletics (eg, dance), and borderline or true hip dysplasia. Surgeon-related factors include overaggressive acetabular rim resection, excessive labral débridement, and lack of capsular repair.^5,9 Although there are multiple techniques for accessing the hip joint and addressing capsular closure at the end of surgery,^9-14 we think capsular closure is an important aspect of the case.

Surgical Technique

For a demonstration of this technique, click here to see the video that accompanies this article. The patient is moved to a traction table and placed in the supine position. Induction of general anesthesia with muscle relaxation allows for atraumatic axial traction. The anesthetized patient is assessed for passive motion and ligamentous laxity. Well-padded boots are applied, and a well-padded perineal post is used for positioning. Gentle traction is applied to the contralateral limb, and axial traction is applied through the surgical limb with the hip abducted and minimally flexed. The leg is then adducted and neutrally extended, inducing a transverse vector cantilever moment to the proximal femur. The foot is internally rotated to optimize femoral neck length on an anteroposterior radiograph. The circulating nursing staff notes the onset of hip distraction in order to ensure safe traction duration.

Bony landmarks are marked with a sterile marking pen. Under fluoroscopic guidance, an anterolateral (AL) portal is established 1 cm proximal and 1 cm anterior to the AL tip of the greater trochanter. Standard cannulation allows for intra-articular visualization with a 70° arthroscope. A needle is used to localize placement of a modified anterior portal. After cannulation, the arthroscope is placed in the modified anterior portal to confirm safe entry of the portal without labral violation. An arthroscopic scalpel (Samurai Blade; Stryker Sports Medicine) is used to make a transverse interportal capsulotomy 8 mm to 10 mm from the labrum and extending from 12 to 2 o’clock; length is 2 cm to 4 cm, depending on the extent of the intra-articular injury (Figure 1A).

T-Capsulotomy

Pericapsular fatty tissue is débrided with an arthroscopic shaver to visualize the interval between the iliocapsularis and gluteus minimus muscles. An arthroscopic scalpel is used, through a 5.0-mm cannula in the DALA portal, to extend the capsulotomy longitudinally and perpendicular to the interportal capsulotomy (Figure 1C). The T-capsulotomy is performed along the length of the femoral neck distally to the capsular reflection at the intertrochanteric line. The arthroscopic burr is used to perform a femoral osteochondroplasty between the lateral synovial folds (12 o’clock) and the medial synovial folds (6 o’clock). Dynamic examination and fluoroscopic imaging confirm that the entire cam deformity has been excised and that there is no evidence of impingement.

Although various suture-shuttling or tissue-penetrating/retrieving devices may be used, we recommend whichever device is appropriate for closing the capsule in its entirety. With the arthroscope in the modified anterior portal, an 8.25-mm × 90-mm cannula is placed in the AL portal, and an 8.25-mm × 110-mm cannula in the DALA portal. These portals will facilitate suture passage.

The vertical limb of the T-capsulotomy is closed with 2 to 4 side-to-side sutures, and the interportal capsulotomy limb with 2 or 3 sutures. Capsular closure begins with the distal portion of the longitudinal limb at the base of the iliofemoral ligament (IFL). A crescent tissue penetrating device (Slingshot; Stryker Sports Medicine) is loaded with high-strength No. 2 suture (Zipline; Stryker Sports Medicine) and placed through the AL portal to sharply pierce the lateral leaflet of the IFL (Figure 1D). The No. 2 suture is shuttled into the intra-articular side of the capsule (Figure 1E). Through the DALA portal, the penetrating device is used to pierce the medial leaflet to retrieve the free suture (Figure 1F). Next, the looped suture retriever is used to pull the suture from the AL portal to the DALA portal so the suture can be tied. We prefer to tie each suture individually after it is passed, but all of the sutures can be passed first, and then tied. As successive suture placement and knot tying inherently tighten the capsule, successive visualization requires more precision. Each subsequent suture is similarly passed, about 1 cm proximal to the previous stitch.

After closure of the vertical limb of the T-capsulotomy, we prefer to close the interportal capsulotomy with the InJector II Capsule Restoration System (Stryker Sports Medicine), a device that allows for closure through a single cannula lateral to medial. This device is passed through the AL cannula in order to bring the suture end through the proximal IFL attached to the acetabulum (Figure 1G). The device is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL (Figure 1H). The stitch is then tensioned and tied. Likewise, closure of the medial IFL involves passing the InJector through the DALA cannula and bringing the first suture end through the proximal IFL attached to the acetabulum. The Injector is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL. The stitch is then tensioned and tied with the hip in neutral extension. Generally, 2 or 3 stitches are used to close the interportal capsulotomy. Complete capsular closure is confirmed by the inability to visualize the underlying femoral head/neck and by probing the anterior capsule to ensure proper tension (Figure 1I).

Extensile Interportal Capsulotomy

An alternative to T-capsulotomy is interportal capsulotomy. Just as with T-capsulotomy closure, multiple different suture passing devices can be used. Good visualization for accessing the peripheral compartment generally is achieved by making the interportal capsulotomy 4 cm to 6 cm longer than the horizontal limb of the T-capsulotomy (Figures 2A, 2B). Capsular closure usually begins with the medial portion of the interportal capsulotomy. With the arthroscope in the AL portal, the 8.25-mm × 90-mm cannula is placed in the midanterior portal (MAP), and an 8.25-mm × 110-mm cannula is placed in the DALA portal.

Ligamentous laxity determines degree of capsular closure. The capsular leaflets can be closed end to end if there is little concern for laxity and instability. If there is more concern for capsular laxity, a larger bite of the capsular tissue can be taken to allow for a greater degree of plication. Further, the interportal capsule can be tightened by alternately advancing the location where sutures are passed through the capsule. Specifically, the sutures are passed such that larger bites of the distal capsule are taken, increasing the tightness of the capsule in external rotation.⁹

Rehabilitation

After surgery, hip extension and external rotation are limited to decrease stress on the capsular closure. The patient is placed into a hip orthosis with 0° to 90° of flexion and a night abduction pillow to limit hip external rotation. Crutch-assisted gait with 20 lb of foot-flat weight-bearing is maintained the first 3 weeks. Continuous passive motion and use of a stationary bicycle are recommended for the first 3 weeks, and then the patient slowly progresses to muscle strengthening, including core and proximal motor control. Closed-chain exercises are begun 6 weeks after surgery. Treadmill running may start at 12 weeks, with the goal of returning to sport at 4 to 6 months.

Discussion

Capsular closure during hip arthroscopy restores the normal anatomy of the IFL and therefore restores the biomechanical characteristics of the hip joint. Scientific studies have found that capsular repair or plication after hip arthroscopy restores normal hip translation, rotation, and strain. Clinical studies have also demonstrated a lower revision rate and more rapid return to athletic activity. Capsular closure, however, is technically challenging and increases operative time, but gross instability and microinstability can be avoided with meticulous closure/plication.

Am J Orthop. 2017;46(1):49-54. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Take-Home Points

• Hip capsule provides static stabilization for the hip joint.
• Capsular management must weigh visualization to address underlying osseous deformity but also repair/plication of the capsule to maintain biomechanical characteristics.
• T-capsulotomy provides optimal visualization with a small interportal incision with a vertical incision along the femoral neck.
• Extensile interportal capsulotomy is the most widely used capsulotomy and size may vary depending on capsular and patient characteristics.
• Orthopedic surgeons should be equipped to employ either technique depending on the patients individual hip pathomorphology.

Hip arthroscopy has emerged as a common surgical treatment for a number of hip pathologies. Surgical treatment strategies, including management of the hip capsule, have evolved. Whereas earlier hip arthroscopies often involved capsulectomy or capsulotomy without repair, more recently capsular closure has been considered an important step in restoring the anatomy of the hip joint and preventing microinstability or gross macroinstability.

The anatomy of the hip joint includes both static and dynamic stabilizers designed to maintain a functioning articulation. The osseous articulation of the femoral head and acetabulum is the first static stabilizer, with variations in offset, version, and inclination of the acetabulum and the proximal femur. The joint capsule consists of 3 ligaments—iliofemoral, pubofemoral, and ischiofemoral—that converge to form the zona orbicularis. Other soft-tissue structures, such as the articular cartilage, the labrum, the transverse acetabular ligament, the pulvinar, and the ligamentum teres, also provide static constraint.¹ The surrounding musculature provides the hip joint with dynamic stability, which contributes to overall maintenance of proper joint kinematics.

Management of the hip capsule has evolved as our understanding of hip pathology and biomechanics has matured. Initial articles on using hip arthroscopy to treat labral tears described improvement in clinical outcomes,² but the cases involved limited focal capsulotomy. Not until the idea of femoroacetabular impingement (FAI) was introduced were extensive capsulotomies and capsulectomies performed to address the underlying osseous deformities and emulate open techniques. Soon after our ability to access osseous pathomorphology improved with enhanced visualization and comprehensive resection, cases of hip instability after hip arthroscopy surfaced.^3-5 Although frank dislocation after hip arthroscopy is rare and largely underreported, it is a catastrophic complication. In addition, focal capsular defects were also described in cases of failed hip arthroscopy and thought to lead to microinstability of the hip.⁶ Iatrogenic microinstability is thought to be more common, but it is also underrecognized as a cause of failure of hip arthroscopy.⁷Microinstability is a pathologic condition that can affect hip function. In cases of recurrent pain and unimproved functional status after surgery, microinstability should be considered. In an imaging study of capsule integrity, McCormick and colleagues⁶ found that 78% of patients who underwent revision arthroscopic surgery after hip arthroscopic surgery for FAI showed evidence of capsular and iliofemoral defects on magnetic resonance angiography. Frank and colleagues⁸ reported that, though all patients showed preoperative-to-postoperative improvement on outcome measures, those who underwent complete repair of their T-capsulotomy (vs repair of only its longitudinal portion) had superior outcomes, particularly increased sport-specific activity.

For patients undergoing hip arthroscopy, several predisposing factors can increase the risk of postoperative instability. Patient-related hip instability factors include generalized ligamentous laxity, supraphysiologic athletics (eg, dance), and borderline or true hip dysplasia. Surgeon-related factors include overaggressive acetabular rim resection, excessive labral débridement, and lack of capsular repair.^5,9 Although there are multiple techniques for accessing the hip joint and addressing capsular closure at the end of surgery,^9-14 we think capsular closure is an important aspect of the case.

Surgical Technique

For a demonstration of this technique, click here to see the video that accompanies this article. The patient is moved to a traction table and placed in the supine position. Induction of general anesthesia with muscle relaxation allows for atraumatic axial traction. The anesthetized patient is assessed for passive motion and ligamentous laxity. Well-padded boots are applied, and a well-padded perineal post is used for positioning. Gentle traction is applied to the contralateral limb, and axial traction is applied through the surgical limb with the hip abducted and minimally flexed. The leg is then adducted and neutrally extended, inducing a transverse vector cantilever moment to the proximal femur. The foot is internally rotated to optimize femoral neck length on an anteroposterior radiograph. The circulating nursing staff notes the onset of hip distraction in order to ensure safe traction duration.

Bony landmarks are marked with a sterile marking pen. Under fluoroscopic guidance, an anterolateral (AL) portal is established 1 cm proximal and 1 cm anterior to the AL tip of the greater trochanter. Standard cannulation allows for intra-articular visualization with a 70° arthroscope. A needle is used to localize placement of a modified anterior portal. After cannulation, the arthroscope is placed in the modified anterior portal to confirm safe entry of the portal without labral violation. An arthroscopic scalpel (Samurai Blade; Stryker Sports Medicine) is used to make a transverse interportal capsulotomy 8 mm to 10 mm from the labrum and extending from 12 to 2 o’clock; length is 2 cm to 4 cm, depending on the extent of the intra-articular injury (Figure 1A).

T-Capsulotomy

Pericapsular fatty tissue is débrided with an arthroscopic shaver to visualize the interval between the iliocapsularis and gluteus minimus muscles. An arthroscopic scalpel is used, through a 5.0-mm cannula in the DALA portal, to extend the capsulotomy longitudinally and perpendicular to the interportal capsulotomy (Figure 1C). The T-capsulotomy is performed along the length of the femoral neck distally to the capsular reflection at the intertrochanteric line. The arthroscopic burr is used to perform a femoral osteochondroplasty between the lateral synovial folds (12 o’clock) and the medial synovial folds (6 o’clock). Dynamic examination and fluoroscopic imaging confirm that the entire cam deformity has been excised and that there is no evidence of impingement.

Although various suture-shuttling or tissue-penetrating/retrieving devices may be used, we recommend whichever device is appropriate for closing the capsule in its entirety. With the arthroscope in the modified anterior portal, an 8.25-mm × 90-mm cannula is placed in the AL portal, and an 8.25-mm × 110-mm cannula in the DALA portal. These portals will facilitate suture passage.

The vertical limb of the T-capsulotomy is closed with 2 to 4 side-to-side sutures, and the interportal capsulotomy limb with 2 or 3 sutures. Capsular closure begins with the distal portion of the longitudinal limb at the base of the iliofemoral ligament (IFL). A crescent tissue penetrating device (Slingshot; Stryker Sports Medicine) is loaded with high-strength No. 2 suture (Zipline; Stryker Sports Medicine) and placed through the AL portal to sharply pierce the lateral leaflet of the IFL (Figure 1D). The No. 2 suture is shuttled into the intra-articular side of the capsule (Figure 1E). Through the DALA portal, the penetrating device is used to pierce the medial leaflet to retrieve the free suture (Figure 1F). Next, the looped suture retriever is used to pull the suture from the AL portal to the DALA portal so the suture can be tied. We prefer to tie each suture individually after it is passed, but all of the sutures can be passed first, and then tied. As successive suture placement and knot tying inherently tighten the capsule, successive visualization requires more precision. Each subsequent suture is similarly passed, about 1 cm proximal to the previous stitch.

After closure of the vertical limb of the T-capsulotomy, we prefer to close the interportal capsulotomy with the InJector II Capsule Restoration System (Stryker Sports Medicine), a device that allows for closure through a single cannula lateral to medial. This device is passed through the AL cannula in order to bring the suture end through the proximal IFL attached to the acetabulum (Figure 1G). The device is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL (Figure 1H). The stitch is then tensioned and tied. Likewise, closure of the medial IFL involves passing the InJector through the DALA cannula and bringing the first suture end through the proximal IFL attached to the acetabulum. The Injector is removed from the cannula, and the other suture end is placed in the device and passed through the distal IFL. The stitch is then tensioned and tied with the hip in neutral extension. Generally, 2 or 3 stitches are used to close the interportal capsulotomy. Complete capsular closure is confirmed by the inability to visualize the underlying femoral head/neck and by probing the anterior capsule to ensure proper tension (Figure 1I).

Extensile Interportal Capsulotomy

An alternative to T-capsulotomy is interportal capsulotomy. Just as with T-capsulotomy closure, multiple different suture passing devices can be used. Good visualization for accessing the peripheral compartment generally is achieved by making the interportal capsulotomy 4 cm to 6 cm longer than the horizontal limb of the T-capsulotomy (Figures 2A, 2B). Capsular closure usually begins with the medial portion of the interportal capsulotomy. With the arthroscope in the AL portal, the 8.25-mm × 90-mm cannula is placed in the midanterior portal (MAP), and an 8.25-mm × 110-mm cannula is placed in the DALA portal.

Ligamentous laxity determines degree of capsular closure. The capsular leaflets can be closed end to end if there is little concern for laxity and instability. If there is more concern for capsular laxity, a larger bite of the capsular tissue can be taken to allow for a greater degree of plication. Further, the interportal capsule can be tightened by alternately advancing the location where sutures are passed through the capsule. Specifically, the sutures are passed such that larger bites of the distal capsule are taken, increasing the tightness of the capsule in external rotation.⁹

Rehabilitation

After surgery, hip extension and external rotation are limited to decrease stress on the capsular closure. The patient is placed into a hip orthosis with 0° to 90° of flexion and a night abduction pillow to limit hip external rotation. Crutch-assisted gait with 20 lb of foot-flat weight-bearing is maintained the first 3 weeks. Continuous passive motion and use of a stationary bicycle are recommended for the first 3 weeks, and then the patient slowly progresses to muscle strengthening, including core and proximal motor control. Closed-chain exercises are begun 6 weeks after surgery. Treadmill running may start at 12 weeks, with the goal of returning to sport at 4 to 6 months.

Discussion

Capsular closure during hip arthroscopy restores the normal anatomy of the IFL and therefore restores the biomechanical characteristics of the hip joint. Scientific studies have found that capsular repair or plication after hip arthroscopy restores normal hip translation, rotation, and strain. Clinical studies have also demonstrated a lower revision rate and more rapid return to athletic activity. Capsular closure, however, is technically challenging and increases operative time, but gross instability and microinstability can be avoided with meticulous closure/plication.

Am J Orthop. 2017;46(1):49-54. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.

Contents

Opioid-Sparing Pain Control in Outpatient Total Joint Arthroplasty

John W. Barrington, MD

Addressing the Opioid Epidemic With Multimodal Pain Management

Michael A. Kelly, MD

Comprehensive Care for Joint Replacement (CJR) Bundle Expense in Perioperative Pain Management

Susan D. Bear, PharmD, BCPS

The Role of Liposomal Bupivacaine in Value-Based Care

Richard Iorio, MD

Click here to read the supplement

Contents

Opioid-Sparing Pain Control in Outpatient Total Joint Arthroplasty

John W. Barrington, MD

Addressing the Opioid Epidemic With Multimodal Pain Management

Michael A. Kelly, MD

Comprehensive Care for Joint Replacement (CJR) Bundle Expense in Perioperative Pain Management

Susan D. Bear, PharmD, BCPS

The Role of Liposomal Bupivacaine in Value-Based Care

Richard Iorio, MD

Click here to read the supplement

Contents

Opioid-Sparing Pain Control in Outpatient Total Joint Arthroplasty

John W. Barrington, MD

Addressing the Opioid Epidemic With Multimodal Pain Management

Michael A. Kelly, MD

Comprehensive Care for Joint Replacement (CJR) Bundle Expense in Perioperative Pain Management

Susan D. Bear, PharmD, BCPS

The Role of Liposomal Bupivacaine in Value-Based Care

Richard Iorio, MD

Click here to read the supplement