Complications and Risk Factors for Morbidity in Elective Hip Arthroscopy: A Review of 1325 Cases

Results

Of the 1325 patients who underwent hip arthroscopy, 60% were female. Regarding age, 52% were younger than 40 years, and 45% were between 45 years and 60 years. The most common diagnoses were articular cartilage disorder involving the pelvic region (15%), enthesopathy of the hip (12%), and joint pain involving the pelvic region or thigh (11%). The most common primary CPT code (50%) was for hip arthroscopic débridement (29862), followed by 24% for arthroscopic labral repair (29916), 16% for arthroscopic femoroplasty (29914), and 9% for arthroscopic acetabuloplasty (29915). Of the 16 complications found, 12 involved hip arthroscopic débridement, and 4 involved hip arthroscopic femoroplasty. There were no complications of arthroscopic acetabuloplasty (29915), arthroscopic labral repair (29916), or hip arthroscopy (29861).

Of the 1325 hip arthroscopy patients, 16 (1.21%) had at least 1 complication (Table 1).

Univariate analysis identified age (P = .014), CPT code (P = .036), hypertension (P = .128), and steroid use (P = .188) as risk factors for any complication (Table 2).

Discussion

Earlier reports on hip arthroscopy did not consider risk factors for systemic morbidity and were mainly single-institution case series.^{3,10,11,13,25} Given a renewed focus on outcomes measurement and quality assessment in orthopedic surgery, we wanted to describe short-term complications of and risk factors for morbidity in hip arthroscopy. In this article, we report baseline data from a large multicenter cohort. For hip arthroscopy, we found low rates of short-term complications (1.21%) and major morbidities (0.45%). We considered many modifiable and nonmodifiable risk factors for complications and found age over 65 years to be an independent risk factor for any complication and minor morbidity. Several of our findings merit further discussion.

Other authors have reported hip arthroscopy complication rates of 1% to 20%, citing both systemic and local complications,^6,8,10-12 and major complication rates of 0.3% to 0.58%.^8,12 Minor complications of hip arthroscopy vary, and depend on definition, with long-term consequences unknown in some cases.⁸ Sensory neuropraxia, a relatively common minor complication in hip arthroscopy, is thought to be affected by the amount of traction against a perineal post and by increased operative time, with operative time under 2 hours previously suggested.^{3,6,10,11,13,25,26}

In the present study, the overall rate of any complication of hip arthroscopy was 1.21%, and the most common complications were bleeding resulting in transfusion, return to operating room, superficial surgical-site infection, and DVT/thrombophlebitis. When we excluded bleeding resulting in transfusion, the overall complication rate fell to 0.75%. Operative time was relatively short, <2 hours for 70% of patients. Last, there were no mortalities. As our data set did not include variables encompassing sensory neuropraxia or iatrogenic chondrolabral injury, we were unable to report on these data.

Surgeons and healthcare systems should be advised that rates of systemic complications in hip arthroscopy are low and that hip arthroscopy is a relatively safe procedure. Surgeons and healthcare systems can refer to our reported complication rates and risk factors when assessing quality and performing cost analysis in hip arthroscopy. For our 1325 patients, the major morbidity rate was 0.45%, within the range of previous reports.^8,12 There were no nerve injuries in our patient cohort, likely because of the strict NSQIP definitions of nerve injury. We cannot report on sensory neuropraxia and iatrogenic chondrolabral injury. We speculate that lack of these variables may have artificially lowered our minor complication rate.

Some authors have reported clinical benefits of hip arthroscopy in older patients,^27-29 whereas others have suggested age may be a negative prognostic factor.^27,30 Suggested indications for hip arthroscopy in an elderly population include chondral defects, labral tears, and FAI in the absence of significant arthritic changes.^28,29 Larson and colleagues,³⁰ who reported a 52% failure rate for osteoarthritis patients who underwent hip arthroscopy for FAI, concluded that arthroscopy should not be offered to patients with evidence of advanced radiographic joint space narrowing. Others have noted that patients who were under age 55 years and had minimal osteoarthritic changes had a longer interval between hip arthroscopy and total hip arthroplasty in comparison with patients over age 55 years.³¹ Previous work in knee arthroscopy found older age (40-65 years vs <40 years) was an independent predictor of short-term complications (1.5 times increased risk).²¹ In the present study, 7.69% of patients who were over age 65 years when they underwent hip arthroscopy had a complication, and we report age over 65 years as an independent risk factor for any complication (OR, 6.52) and minor morbidity (OR, 7.97). Surgeons should be aware that advanced age is an independent risk factor for complications in hip arthroscopy. Potential benefits of hip arthroscopy should be carefully weighed against the increased risk in this patient cohort, and surgeons should ascertain the scope of an elderly patient’s disease to determine if hip arthroscopy is indicated and worth the potential risks.

To our knowledge, bleeding resulting in transfusion was not previously described as a complication of hip arthroscopy. In the present study, bleeding resulting in transfusion was the most common complication (6 patients, 0.45%), and all the affected patients had a primary CPT code for arthroscopic débridement (29862). The 6 primary diagnoses were hip osteoarthrosis (3), thigh/pelvis pain (1), unspecified injury (1), and congenital hip deformity (1). The 6 transfusion patients also tended to be older (ages 30, 53, 64, 67, 76, and 90 years). Although drawing firm conclusions from so few patients would be inappropriate, we acknowledge that the majority who received a transfusion were older, underwent arthroscopic débridement of a hip, and had a primary diagnosis of osteoarthrosis or pain. As transfusion practices can differ between surgeons and groups, we conclude that the risk for bleeding requiring transfusion is low in hip arthroscopy. Patients who are older and who undergo arthroscopic débridement of an osteoarthritic hip may be at elevated risk for transfusion.

This study had several limitations. First, with use of the NSQIP database, follow-up was limited to 30 days. We speculate that longer follow-up might yield higher complication rates and additional risk factors. Second, we could not distinguish individual surgeon or site data and acknowledge complications might differ between surgeons and sites that perform hip arthroscopy more frequently. Third, as data were limited to medical and broadly applicable surgical variables included in the NSQIP database, they might not be specific to hip arthroscopy, and we cannot report on iatrogenic chondrolabral injury and neuropraxia, 2 previously reported minor complications in hip arthroscopy. We speculate that data collection focused on problems specific to hip arthroscopy would yield more complications and risk factors.