Summary

Patients with global acetabular retroversion had significantly inferior total hip arthroplasty-free survivorship at minimum 8-year follow-up relative to matched controls and greater rates of severe chondrolabral junction breakdown, despite no differences in patient reported outcome measures at final follow-up

Abstract

Introduction

Global acetabular retroversion has been associated with increased risk of hip osteoarthritis, femoroacetabular impingement (FAI), and intraarticular soft tissue pathology. However, the role of global retroversion on total hip arthroplasty (THA)-free survivorship has not been explored. The objective of this study is to compare long-term survivorship following primary hip arthroscopy between patients with global acetabular retroversion and a propensity-matched control group.

Methods

This retrospective study queried patients >18 years and minimum 8-year follow-up that underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to FAI. Patients with global acetabular retroversion, as indicated by the combined presence of a crossover sign, ischial spine sign, and posterior wall sign on preoperative pelvic radiographs, were 1:1 propensity-score matched by age, sex, body mass index (BMI), and labral treatment (repair versus debridement) to controls without global retroversion. Baseline demographic, radiographic, and intraoperative variables were compared between cohorts. Cox multivariate regression controlling for global retroversion and Tönnis grade was used to assess conversion to THA. Patient-reported outcome measures (PROMs) were compared between cohorts.

Results

Overall, 49 patients with global retroversion were 1:1 matched to 49 controls, with mean follow-up of 10.7 ± 2.1 years and 11.1 ± 2.8 years, respectively (P=0.524). There were no significant differences in baseline demographics and radiographic findings between cohorts (P>0.05 for each). Patients with global acetabular retroversion had significantly greater rates of severe chondrolabral junction (CLJ) breakdown (P=0.010). Unadjusted Kaplan-Meier survival curves analyzed by log-rank test demonstrated a significantly decreased survivorship among patients with global retroversion (68.6%) compared to controls (83.9%) at final follow-up (P=0.036). Cox multivariable regression controlling for Tönnis grade demonstrated that patients with global retroversion had a significantly greater risk of THA conversion (hazard ratio, 3.94; p=0.038). There were no differences in all PROMs at final follow-up (P>0.05 for all).

Conclusion

Patients with global acetabular retroversion had significantly inferior THA-free survivorship at minimum 8-year follow-up relative to matched controls and greater rates of severe CLJ breakdown, despite no differences in PROMs at final follow-up. These findings suggest that global retroversion on preoperative radiographic assessment may be a useful predictor of long-term failure.