EP8.99 Staged Bilateral Hip Arthroscopy for Femoroacetabular Impingement Syndrome Results in Comparable Outcomes Between Hips Despite Younger Age and Greater Deformity when Compared to Unilateral Hip Arthroscopy Patients

Abstract

Abstract Background Femoroacetabular impingement syndrome (FAIS) frequently presents bilaterally, but limited research has compared patients undergoing unilateral versus staged bilateral hip arthroscopy. This study evaluated demographic, radiographic, and surgical differences between these groups and identified predictors of postoperative patient-reported outcome (PRO) performance. We hypothesized that bilateral patients would differ in preoperative PROs but have similar radiographic findings and postoperative outcomes. Methods A prospectively maintained single-institution database was reviewed for patients undergoing hip arthroscopy for FAIS from December 2018 to September 2025. Inclusion criteria were a clinical and radiographic diagnosis of FAIS, minimum 1-year follow-up, and at least 1 completed 12-month PRO. Bilateral patients presented with bilateral pain and underwent staged hip arthroscopy, unilateral patients did not undergo contralateral surgery during the study period. Demographics, radiographic measurements, intraoperative findings, and PROs (iHOT-12, HOS-ADL, HOS-SS) were recorded. Mixed-effects models assessed predictors of PRO performance and compared preoperative measures between groups, while paired t tests compared first and second hips. Results A total of 733 patients met inclusion criteria (590 unilateral, 143 bilateral). Patients who presented with bilateral hip pain were younger (27.7 ± 10.6 vs 33.4 ± 11.3 years; p < 0.0001), more often male (49.6% vs 36.0%; p = 0.0025), and had greater alpha angles (60.9° vs 57.6°; p = 0.0181), with no other radiographic differences. Preoperative iHOT-12 (46.9 ± 17.8 vs 41.7 ± 18.2; p = 0.0047) and HOS-ADL (75.1 ± 14.1 vs 71.3 ± 16.5; p = 0.0103) were higher in bilateral patients. Both first and second hip arthroscopies were associated with significant PRO improvement over time (all p < 0.0001), with no difference in PRO trajectories for iHOT-12 (p = 0.062), HOS-ADL (p = 0.0719), or HOS-SS (p = 0.1843). The second hip had higher femoral version than the first (11.3° ± 10.3° vs 9.8° ± 10.6°; p = 0.0009). Age was the only consistent negative predictor across all PROs (p < 0.0001). Conclusion Patients undergoing staged bilateral hip arthroscopy for FAIS were younger, more often male, and had larger cam deformities than unilateral patients, but otherwise had similar radiographic and postoperative findings. In staged bilateral cases, first- and second-side arthroscopy yielded comparable PRO improvement.