Global Acetabular Retroversion Is Associated With an Increased Risk of Conversion to Total Hip Arthroplasty After Primary Hip Arthroscopic Surgery: A Propensity Score-Matched Analysis With a Minimum 8-Year Follow-up.

Background: Global acetabular retroversion has been associated with an increased risk of hip osteoarthritis, femoroacetabular impingement, and intra-articular soft tissue abnormalities. However, the role of global acetabular retroversion on total hip arthroplasty (THA)-free survivorship has not been explored.

Purpose: To compare long-term THA-free survivorship after primary hip arthroscopic surgery between patients with global acetabular retroversion and a propensity score-matched control group without global acetabular retroversion.

Study design: Cohort study; Level of evidence, 3.

Methods: This retrospective study examined patients aged ≥18 years with a minimum 8-year follow-up who underwent primary hip arthroscopic surgery by a single surgeon between May 2001 and September 2013 for the treatment of symptomatic labral tears secondary to femoroacetabular impingement. Patients with global acetabular retroversion, indicated by the combined presence of a crossover sign, ischial spine sign, and posterior wall sign on preoperative supine pelvic radiographs, were 1:1 propensity score matched by age, sex, body mass index, and labral treatment (repair vs debridement) to controls without global acetabular retroversion. Patient, radiographic, and intraoperative variables were compared between groups. Cox multivariate regression, controlling for global acetabular retroversion and Tönnis grade, was used to assess conversion to THA. Patient-reported outcome measure (PROM) scores were also compared between groups.

Results: Overall, 49 patients (49 hips) with global acetabular retroversion were 1:1 matched to 49 controls, with a mean follow-up of 10.7 ± 2.1 and 11.1 ± 2.8 years, respectively (P = .524). There were no significant differences in patient characteristics and radiographic findings between groups. Patients with global acetabular retroversion had significantly greater rates of severe chondrolabral junction breakdown (P = .010). Unadjusted Kaplan-Meier survival curves analyzed by the log-rank test demonstrated significantly decreased survivorship among patients with global acetabular retroversion (68.6%) compared with matched controls (83.9%) at final follow-up (P = .036). Cox multivariate regression demonstrated that patients with global acetabular retroversion had a significantly greater risk of conversion to THA (hazard ratio, 3.94; P = .039). There were no statistically significant differences in any PROM scores at final follow-up.

Conclusion: Patients with global acetabular retroversion had significantly inferior THA-free survivorship at a minimum 8-year follow-up after hip arthroscopic surgery relative to matched controls as well as greater rates of severe chondrolabral junction breakdown, despite no statistically significant differences in PROM scores at final follow-up among patients not converting to THA. These findings suggest that global acetabular retroversion on preoperative radiographic assessments may be a valuable predictor of long-term failure after hip arthroscopic surgery.