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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. 
AP radiographs allow for evaluation of fractures, intraosseous sclerosis, acetabular depth, inclination and version, acetabular overcoverage, joint-space narrowing, femoroacetabular congruency, femoral head sphericity, and femoral head–neck offset.7,8,10 Inspection for labral calcification is important, as it can indicate repetitive damage at the extremes of range of motion.
On AP pelvis radiographs, it is important to distinguish coxa profunda from acetabular protrusion. These entities are on the same pathomorphologic spectrum and are similar but distinctively different. Coxa profunda refers to the depth of the acetabulum relative to the ilioischial line, and acetabular protrusion refers to the depth (or medial position) of the femoral head relative to the ilioischial line. Each condition suggests—but is not diagnostic for—pincer-type femoroacetabular impingement (FAI).11Acetabular rotation is another important entity that can be evaluated on well-centered, nontilted AP pelvic radiographs. Acetabular rotation refers to the opening direction of the acetabulum. It may be anterior (anteverted), neutral, or posterior (retroverted). Anteversion is present when the anterior acetabular rim does not traverse the posterior rim shadow4; in other words, the ring formed by the acetabulum is not twisted. When the walls overlap but do not intersect, the cup has neutral version. Retroversion is qualitatively determined by the crossover (figure-of-8) and posterior wall signs12 and is associated with pincer-type FAI and the development of hip osteoarthritis.12Dunn lateral radiographs (Figure 2A), taken with 90° hip flexion, were originally used to measure femoral neck anteversion.13 
False-profile radiographs (Figure 6), valuable in evaluating anterior acetabular coverage and femoral head–neck junction morphology,14,15 allow characterization of both cam-type and pincer-type FAI. 
Quantitative measures warrant specific consideration (Table). Femoroacetabular morphology is quantitatively measured by α angle, Tönnis angle (acetabular inclination angle), and lateral center-edge angle (LCEA).7,8,10 The α angle (Figure 4) detects the loss of normal anterosuperior femoral head–neck junction concavity caused by a convex osseous prominence. An α angle >50° represents a cam deformity.16 In a cohort study of 338 patients, Nepple and colleagues17 qualitatively associated increased α angle with severe intra-articular hip disease. Murphy and colleagues18 found a Tönnis angle >15° to be a poor prognostic factor in untreated hip dysplasia. LCEA quantifies superolateral femoral head coverage,19 and its normal range is 20° to 40°.20 LCEA <20° indicates dysplasia of the femoroacetabular joint, and LCEA >40° indicates overcoverage and pincer-type FAI. As with any quantitative radiographic measurement, results should be interpreted within the presenting clinical context.
Radiographic findings, even findings based on these special radiographs, may underestimate the pathologic process. 
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
Chondral damage is identified much as labral tears are. With chondral injury, the normal intermediate signal is interrupted by a fluid-intense signal extending to the subchondral bone. A fat-saturated T2or short-tau inversion recovery (STIR) sequence is useful in emphasizing this finding.27
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.
1. McCall DA, Safran MR. MRI and arthroscopy correlations of the hip: a case-based approach. Instr Course Lect . 2012;61:327-344.
2. Register B, Pennock AT, Ho CP, Strickland CD, Lawand A, Philippon MJ. Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Am J Sports Med . 2012;40(12):2720-2724.
3. Campbell SE. Radiography of the hip: lines, signs, and patterns of disease. Semin Roentgenol . 2005;40(3):290-319.
4. Clohisy JC, Carlisle JC, Beaulé PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am . 2008;90(suppl 4):47-66.
5. Malviya A, Raza A, Witt JD. Reliability in the diagnosis of femoroacetabular impingement and dysplasia among hip surgeons: role of surgeon volume and experience. Hip Int . 2016;26(3):284-289.
6. Nepple JJ, Martel JM, Kim YJ, Zaltz I, Clohisy JC, Group AS. Do plain radiographs correlate with CT for imaging of cam-type femoroacetabular impingement? Clin Orthop Relat Res . 2012;470(12):3313-3320.
7. Kosuge D, Cordier T, Solomon LB, Howie DW. Dilemmas in imaging for peri-acetabular osteotomy: the influence of patient position and imaging technique on the radiological features of hip dysplasia. Bone Joint J . 2014;96(9):1155-1160.
8. Tannast M, Fritsch S, Zheng G, Siebenrock KA, Steppacher SD. Which radiographic hip parameters do not have to be corrected for pelvic rotation and tilt? Clin Orthop Relat Res . 2015;473(4):1255-1266.
9. Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study of pelves from cadavers. Clin Orthop Relat Res . 2003;(407):241-248.
10. Griffin JW, Weber AE, Kuhns B, Lewis P, Nho SJ. Imaging in hip arthroscopy for femoroacetabular impingement: a comprehensive approach. Clin Sports Med . 2016;35(3):331-344.
11. Nepple JJ, Lehmann CL, Ross JR, Schoenecker PL, Clohisy JC. Coxa profunda is not a useful radiographic parameter for diagnosing pincer-type femoroacetabular impingement. J Bone Joint Surg Am . 2013;95(5):417-423.
12. Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum. A cause of hip pain. J Bone Joint Surg Br . 1999;81(2):281-288.
13. Dunn DM. Anteversion of the neck of the femur; a method of measurement. J Bone Joint Surg Br . 1952;34(2):181-186.
14. Meyer DC, Beck M, Ellis T, Ganz R, Leunig M. Comparison of six radiographic projections to assess femoral head/neck asphericity. Clin Orthop Relat Res . 2006;(445):181-185.
15. Hellman MD, Mascarenhas R, Gupta A, et al. The false-profile view may be used to identify cam morphology. Arthroscopy . 2015;31(9):1728-1732.
16. Barton C, Salineros MJ, Rakhra KS, Beaulé PE. Validity of the alpha angle measurement on plain radiographs in the evaluation of cam-type femoroacetabular impingement. Clin Orthop Relat Res . 2011;469(2):464-469.
17. Nepple JJ, Carlisle JC, Nunley RM, Clohisy JC. Clinical and radiographic predictors of intra-articular hip disease in arthroscopy. Am J Sports Med . 2011;39(2):296-303.
18. Murphy SB, Ganz R, Muller ME. The prognosis in untreated dysplasia of the hip. A study of radiographic factors that predict the outcome. J Bone Joint Surg Am . 1995;77(7):985-989.
19. Mast NH, Impellizzeri F, Keller S, Leunig M. Reliability and agreement of measures used in radiographic evaluation of the adult hip. Clin Orthop Relat Res . 2011;469(1):188-199.
20. Monazzam S, Bomar JD, Cidambi K, Kruk P, Hosalkar H. Lateral center-edge angle on conventional radiography and computed tomography. Clin Orthop Relat Res . 2013;471(7):2233-2237.
21. Weber AE, Jacobson JA, Bedi A. A review of imaging modalities for the hip. Curr Rev Musculoskelet Med . 2013;6(3):226-234.
22. Bencardino JT, Palmer WE. Imaging of hip disorders in athletes. Radiol Clin North Am . 2002;40(2):267-287, vi-vii.
23. Byrd JW, Jones KS. Diagnostic accuracy of clinical assessment, magnetic resonance imaging, magnetic resonance arthrography, and intra-articular injection in hip arthroscopy patients. Am J Sports Med . 2004;32(7):1668-1674.
24. Mintz DN, Hooper T, Connell D, Buly R, Padgett DE, Potter HG. Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging. Arthroscopy . 2005;21(4):385-393.
25. Blankenbaker DG, De Smet AA, Keene JS, Fine JP. Classification and localization of acetabular labral tears. Skeletal Radiol . 2007;36(5):391-397.
26. Aydingöz U, Oztürk MH. MR imaging of the acetabular labrum: a comparative study of both hips in 180 asymptomatic volunteers. Eur Radiol . 2001;11(4):567-574.
27. Gold GE, Chen CA, Koo S, Hargreaves BA, Bangerter NK. Recent advances in MRI of articular cartilage. AJR Am J Roentgenol . 2009;193(3):628-638.
28. Liong SY, Whitehouse RW. Lower extremity and pelvic stress fractures in athletes. Br J Radiol . 2012;85(1016):1148-1156.
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.
AP radiographs allow for evaluation of fractures, intraosseous sclerosis, acetabular depth, inclination and version, acetabular overcoverage, joint-space narrowing, femoroacetabular congruency, femoral head sphericity, and femoral head–neck offset.7,8,10 Inspection for labral calcification is important, as it can indicate repetitive damage at the extremes of range of motion.
On AP pelvis radiographs, it is important to distinguish coxa profunda from acetabular protrusion. These entities are on the same pathomorphologic spectrum and are similar but distinctively different. Coxa profunda refers to the depth of the acetabulum relative to the ilioischial line, and acetabular protrusion refers to the depth (or medial position) of the femoral head relative to the ilioischial line. Each condition suggests—but is not diagnostic for—pincer-type femoroacetabular impingement (FAI).11Acetabular rotation is another important entity that can be evaluated on well-centered, nontilted AP pelvic radiographs. Acetabular rotation refers to the opening direction of the acetabulum. It may be anterior (anteverted), neutral, or posterior (retroverted). Anteversion is present when the anterior acetabular rim does not traverse the posterior rim shadow4; in other words, the ring formed by the acetabulum is not twisted. When the walls overlap but do not intersect, the cup has neutral version. Retroversion is qualitatively determined by the crossover (figure-of-8) and posterior wall signs12 and is associated with pincer-type FAI and the development of hip osteoarthritis.12Dunn lateral radiographs (Figure 2A), taken with 90° hip flexion, were originally used to measure femoral neck anteversion.13
False-profile radiographs (Figure 6), valuable in evaluating anterior acetabular coverage and femoral head–neck junction morphology,14,15 allow characterization of both cam-type and pincer-type FAI.
Quantitative measures warrant specific consideration (Table). Femoroacetabular morphology is quantitatively measured by α angle, Tönnis angle (acetabular inclination angle), and lateral center-edge angle (LCEA).7,8,10 The α angle (Figure 4) detects the loss of normal anterosuperior femoral head–neck junction concavity caused by a convex osseous prominence. An α angle >50° represents a cam deformity.16 In a cohort study of 338 patients, Nepple and colleagues17 qualitatively associated increased α angle with severe intra-articular hip disease. Murphy and colleagues18 found a Tönnis angle >15° to be a poor prognostic factor in untreated hip dysplasia. LCEA quantifies superolateral femoral head coverage,19 and its normal range is 20° to 40°.20 LCEA <20° indicates dysplasia of the femoroacetabular joint, and LCEA >40° indicates overcoverage and pincer-type FAI. As with any quantitative radiographic measurement, results should be interpreted within the presenting clinical context.
Radiographic findings, even findings based on these special radiographs, may underestimate the pathologic process.
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
Chondral damage is identified much as labral tears are. With chondral injury, the normal intermediate signal is interrupted by a fluid-intense signal extending to the subchondral bone. A fat-saturated T2or short-tau inversion recovery (STIR) sequence is useful in emphasizing this finding.27
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.
AP radiographs allow for evaluation of fractures, intraosseous sclerosis, acetabular depth, inclination and version, acetabular overcoverage, joint-space narrowing, femoroacetabular congruency, femoral head sphericity, and femoral head–neck offset.7,8,10 Inspection for labral calcification is important, as it can indicate repetitive damage at the extremes of range of motion.
On AP pelvis radiographs, it is important to distinguish coxa profunda from acetabular protrusion. These entities are on the same pathomorphologic spectrum and are similar but distinctively different. Coxa profunda refers to the depth of the acetabulum relative to the ilioischial line, and acetabular protrusion refers to the depth (or medial position) of the femoral head relative to the ilioischial line. Each condition suggests—but is not diagnostic for—pincer-type femoroacetabular impingement (FAI).11Acetabular rotation is another important entity that can be evaluated on well-centered, nontilted AP pelvic radiographs. Acetabular rotation refers to the opening direction of the acetabulum. It may be anterior (anteverted), neutral, or posterior (retroverted). Anteversion is present when the anterior acetabular rim does not traverse the posterior rim shadow4; in other words, the ring formed by the acetabulum is not twisted. When the walls overlap but do not intersect, the cup has neutral version. Retroversion is qualitatively determined by the crossover (figure-of-8) and posterior wall signs12 and is associated with pincer-type FAI and the development of hip osteoarthritis.12Dunn lateral radiographs (Figure 2A), taken with 90° hip flexion, were originally used to measure femoral neck anteversion.13
False-profile radiographs (Figure 6), valuable in evaluating anterior acetabular coverage and femoral head–neck junction morphology,14,15 allow characterization of both cam-type and pincer-type FAI.
Quantitative measures warrant specific consideration (Table). Femoroacetabular morphology is quantitatively measured by α angle, Tönnis angle (acetabular inclination angle), and lateral center-edge angle (LCEA).7,8,10 The α angle (Figure 4) detects the loss of normal anterosuperior femoral head–neck junction concavity caused by a convex osseous prominence. An α angle >50° represents a cam deformity.16 In a cohort study of 338 patients, Nepple and colleagues17 qualitatively associated increased α angle with severe intra-articular hip disease. Murphy and colleagues18 found a Tönnis angle >15° to be a poor prognostic factor in untreated hip dysplasia. LCEA quantifies superolateral femoral head coverage,19 and its normal range is 20° to 40°.20 LCEA <20° indicates dysplasia of the femoroacetabular joint, and LCEA >40° indicates overcoverage and pincer-type FAI. As with any quantitative radiographic measurement, results should be interpreted within the presenting clinical context.
Radiographic findings, even findings based on these special radiographs, may underestimate the pathologic process.
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
Chondral damage is identified much as labral tears are. With chondral injury, the normal intermediate signal is interrupted by a fluid-intense signal extending to the subchondral bone. A fat-saturated T2or short-tau inversion recovery (STIR) sequence is useful in emphasizing this finding.27
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.
1. McCall DA, Safran MR. MRI and arthroscopy correlations of the hip: a case-based approach. Instr Course Lect . 2012;61:327-344.
2. Register B, Pennock AT, Ho CP, Strickland CD, Lawand A, Philippon MJ. Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Am J Sports Med . 2012;40(12):2720-2724.
3. Campbell SE. Radiography of the hip: lines, signs, and patterns of disease. Semin Roentgenol . 2005;40(3):290-319.
4. Clohisy JC, Carlisle JC, Beaulé PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am . 2008;90(suppl 4):47-66.
5. Malviya A, Raza A, Witt JD. Reliability in the diagnosis of femoroacetabular impingement and dysplasia among hip surgeons: role of surgeon volume and experience. Hip Int . 2016;26(3):284-289.
6. Nepple JJ, Martel JM, Kim YJ, Zaltz I, Clohisy JC, Group AS. Do plain radiographs correlate with CT for imaging of cam-type femoroacetabular impingement? Clin Orthop Relat Res . 2012;470(12):3313-3320.
7. Kosuge D, Cordier T, Solomon LB, Howie DW. Dilemmas in imaging for peri-acetabular osteotomy: the influence of patient position and imaging technique on the radiological features of hip dysplasia. Bone Joint J . 2014;96(9):1155-1160.
8. Tannast M, Fritsch S, Zheng G, Siebenrock KA, Steppacher SD. Which radiographic hip parameters do not have to be corrected for pelvic rotation and tilt? Clin Orthop Relat Res . 2015;473(4):1255-1266.
9. Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study of pelves from cadavers. Clin Orthop Relat Res . 2003;(407):241-248.
10. Griffin JW, Weber AE, Kuhns B, Lewis P, Nho SJ. Imaging in hip arthroscopy for femoroacetabular impingement: a comprehensive approach. Clin Sports Med . 2016;35(3):331-344.
11. Nepple JJ, Lehmann CL, Ross JR, Schoenecker PL, Clohisy JC. Coxa profunda is not a useful radiographic parameter for diagnosing pincer-type femoroacetabular impingement. J Bone Joint Surg Am . 2013;95(5):417-423.
12. Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum. A cause of hip pain. J Bone Joint Surg Br . 1999;81(2):281-288.
13. Dunn DM. Anteversion of the neck of the femur; a method of measurement. J Bone Joint Surg Br . 1952;34(2):181-186.
14. Meyer DC, Beck M, Ellis T, Ganz R, Leunig M. Comparison of six radiographic projections to assess femoral head/neck asphericity. Clin Orthop Relat Res . 2006;(445):181-185.
15. Hellman MD, Mascarenhas R, Gupta A, et al. The false-profile view may be used to identify cam morphology. Arthroscopy . 2015;31(9):1728-1732.
16. Barton C, Salineros MJ, Rakhra KS, Beaulé PE. Validity of the alpha angle measurement on plain radiographs in the evaluation of cam-type femoroacetabular impingement. Clin Orthop Relat Res . 2011;469(2):464-469.
17. Nepple JJ, Carlisle JC, Nunley RM, Clohisy JC. Clinical and radiographic predictors of intra-articular hip disease in arthroscopy. Am J Sports Med . 2011;39(2):296-303.
18. Murphy SB, Ganz R, Muller ME. The prognosis in untreated dysplasia of the hip. A study of radiographic factors that predict the outcome. J Bone Joint Surg Am . 1995;77(7):985-989.
19. Mast NH, Impellizzeri F, Keller S, Leunig M. Reliability and agreement of measures used in radiographic evaluation of the adult hip. Clin Orthop Relat Res . 2011;469(1):188-199.
20. Monazzam S, Bomar JD, Cidambi K, Kruk P, Hosalkar H. Lateral center-edge angle on conventional radiography and computed tomography. Clin Orthop Relat Res . 2013;471(7):2233-2237.
21. Weber AE, Jacobson JA, Bedi A. A review of imaging modalities for the hip. Curr Rev Musculoskelet Med . 2013;6(3):226-234.
22. Bencardino JT, Palmer WE. Imaging of hip disorders in athletes. Radiol Clin North Am . 2002;40(2):267-287, vi-vii.
23. Byrd JW, Jones KS. Diagnostic accuracy of clinical assessment, magnetic resonance imaging, magnetic resonance arthrography, and intra-articular injection in hip arthroscopy patients. Am J Sports Med . 2004;32(7):1668-1674.
24. Mintz DN, Hooper T, Connell D, Buly R, Padgett DE, Potter HG. Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging. Arthroscopy . 2005;21(4):385-393.
25. Blankenbaker DG, De Smet AA, Keene JS, Fine JP. Classification and localization of acetabular labral tears. Skeletal Radiol . 2007;36(5):391-397.
26. Aydingöz U, Oztürk MH. MR imaging of the acetabular labrum: a comparative study of both hips in 180 asymptomatic volunteers. Eur Radiol . 2001;11(4):567-574.
27. Gold GE, Chen CA, Koo S, Hargreaves BA, Bangerter NK. Recent advances in MRI of articular cartilage. AJR Am J Roentgenol . 2009;193(3):628-638.
28. Liong SY, Whitehouse RW. Lower extremity and pelvic stress fractures in athletes. Br J Radiol . 2012;85(1016):1148-1156.
1. McCall DA, Safran MR. MRI and arthroscopy correlations of the hip: a case-based approach. Instr Course Lect . 2012;61:327-344.
2. Register B, Pennock AT, Ho CP, Strickland CD, Lawand A, Philippon MJ. Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study. Am J Sports Med . 2012;40(12):2720-2724.
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