Ten-year outcome of hip arthroscopy versus conservative management for cam femoroacetabular impingement syndrome: a case-matched cohort study

Abstract Few studies compared hip arthroscopy and conservative management without reporting long-term clinical and radiological outcomes for femoroacetabular impingement syndrome (FAIS). The study hypothesis was that long-term outcome is better after hip arthroscopy than conservative management of FAIS. This single-center, retrospective case-matched cohort study included symptomatic cam FAIS patients undergoing hip arthroscopy (n = 16) or conservative management (n = 16, despite being recommended for surgery) with ≥ 10 years follow-up (median 144.0 (IQR 19.0) months). Patients were matched for age, alpha angle, lateral center edge angle category, and acetabular retroversion, with no difference in baseline osteoarthritis (OA). Baseline data were obtained by chart review, and all patients were re-invited for a final clinical and radiological follow-up. The primary outcome was hip pain (numeric rating scale 0–100). Matched-pairs analyses with within-pair regression were adjusted for body mass index (BMI), baseline hip pain and Tönnis grade. Baseline hip pain was higher in the arthroscopy group (80.0 vs. 50.0, p = 0.002). At follow-up, pain did not differ (5.0 vs. 10.0, p = 0.855). Pain improved more after arthroscopy (− 60.0 vs. − 34.0, p = 0.010), but not after adjustment (coefficient = − 3.1 (95% confidence interval (CI) − 32.5 to 26.4), p = 0.825). No other patient-reported outcome differed. Postoperative OA grade was higher in the arthroscopy group ( p = 0.050) but not after adjustment for BMI and preoperative Tönnis grade (OR 4.6 (95% CI 0.3–62.4), p = 0.251). In this series, after a minimum follow-up of 10 years, clinical and radiographic outcomes were similar in selected patients with previously symptomatic FAIS, whether treated with hip arthroscopy using historical surgical techniques including labral debridement or managed conservatively. No outcome differed significantly after adjustment. Greater pain improvement after arthroscopy reflected higher baseline pain and did not persist after adjustment.