Differences in Outcomes After Primary Hip Arthroscopy Based on Global Acetabular Retroversion Among Patients With Femoroacetabular Impingement Syndrome: A Matched Cohort Study With Minimum 10-Year Follow-up

Background: Patients with femoroacetabular impingement syndrome (FAIS) due to pincer impingement may have global retroversion. Previously treated with periacetabular osteotomy, this condition has been increasingly treated arthroscopically; however, no evidence is available regarding long-term outcomes of these patients. Purpose: To compare hip survivorship and patient-reported outcome measures (PROMs) after primary hip arthroscopy with a minimum of 10-year follow-up between patients who had FAIS with and without radiographic signs of global acetabular retroversion. Study Design: Cohort study; Level of evidence, 3. Methods: This is a retrospective matched-cohort study from a single surgeon's hip arthroscopy database. The study included patients who underwent primary hip arthroscopy for FAIS, had preoperative hip radiographs, and had PROMs at baseline and at least 10 years of follow-up. Global retroversion was identified by the presence of 3 radiographic parameters on anteroposterior radiographs: ischial spine sign, posterior wall sign, and crossover sign. Patients with FAIS who had global retroversion were matched 1:1 with FAIS controls by age, sex, and body mass index (BMI). The modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) were assessed preoperatively and at follow-up. A composite outcome of failure was defined as undergoing a secondary procedure (either revision arthroscopy or total hip arthroplasty) or failure to achieve minimal clinically important difference (MCID) for either mHHS or NAHS. Paired t tests and Wilcoxon signed-rank tests were used to compare PROMs between groups and improvements from baseline. Linear regressions identified predictors of poor outcomes. A P value <.05 was considered statistically significant. Results: Of the 163 eligible patients, 53 met criteria for global retroversion and were matched with 53 controls. Baseline characteristics, including age, sex, BMI, laterality, symptom duration, and preoperative radiographic measurements, were similar between groups. Overall failure rate was 25.5% for the retroversion group compared with 18.8% in controls, which was not statistically significant ( P = .480). Both groups showed significant improvements in mHHS and NAHS from baseline to 5 and 10 years ( P < .001). No difference was noted between groups in 5- or 10-year outcome scores, changes in outcome scores, or achievement of MCID. Subgroup analysis indicated that within the global retroversion group, increased age predicted worse 10-year mHHS and NAHS ( P < .001 and P = .003, respectively). Increased BMI was correlated with worse PROMs in both groups. Conclusion: Patients with global retroversion undergoing hip arthroscopy for FAIS did not have increased failure rates compared with patients without global retroversion and demonstrated significant improvement in outcome scores at 10 years.