Background: As the number of hip arthroscopy cases performed annually continues to rise, so does the number of patients requiring revision surgery. Determining the cause of failed hip arthroscopy (HA) can be challenging, with residual femoroacetabular impingement (FAI) being the most common indication for revision. While addressing impingement during primary HA is critical, factors such as articular cartilage defects, labral pathology, and capsular management also influence outcomes. Purpose: To evaluate trends in revision hip arthroscopy indications at a single institution and assess whether outcomes differ by the primary indication for revision. Study Design: Case series; Level of evidence, 4. Methods: A single-center hip preservation registry was reviewed to identify patients who underwent revision hip arthroscopy for FAI between 2012 and 2019. Patient demographics and primary indications for revision hip arthroscopy were determined, and patient-reported outcomes were collected preoperatively and at a mean follow-up of 5.2 years postoperatively. Results: A total of 173 patients met inclusion criteria for this study. The top 4 primary indications for revision were as follows: residual FAI, 67.8%; capsular instability, 14.6%; heterotopic ossification, 4.6%; and adhesions, 4.2%. Trends in indication did not vary over time. On average, patients significantly improved pre- to postoperatively in the modified Harris Hip Score (21.7; 95% CI, 18.6-24.7), Hip Outcome Score (HOS)–Activities of Daily Living (15.3; 95% CI, 12.1-18.5), HOS–Sport-Specific Subscale (24.1; 95% CI, 19.2-29.1), and International Hip Outcome Tool–33 (30.7; 95% CI, 26.6-34.9; P < .001). Rates of achieving the minimal clinically important difference varied from 67.2% to 82.1%, the substantial clinical benefit from 41% to 56%, and the substantial clinical benefit by absolute value at final follow-up from 45% to 64.8%. In the subgroup analysis, significantly lower preoperative function was noted in the capsular instability cohort when compared with the impingement cohort, as measured by only the HOS–Sport-Specific Subscale ( P = .004). Postoperatively, the capsular instability cohort demonstrated significantly worse outcomes as measured by the International Hip Outcome Tool–33 ( P = .018), HOS–Activities of Daily Living ( P = .015), and modified Harris Hip Score ( P = .024). However, there was no significant difference in the net change in pre- to postoperative patient-reported outcome scores when the different indications for revision HA were compared. The rate of re-revision arthroscopy was 6.4%, and 6.9% of patients converted to total hip arthroplasty at a mean age of 40 years. Conclusion: The most common indication for revision hip arthroscopy in the treatment of femoroacetabular impingement remains residual impingement. Capsular instability has significant consequences for function and may represent a subset of patients who demonstrate more dysfunction before and after revision arthroscopy.
Selley et al. (Fri,) studied this question.