EP8.77 Long-Term Year Outcomes in Patients Aged 40 Years and Older With Borderline Dysplasia After Hip Arthroscopy for Femoroacetabular Impingement

Abstract

Abstract Purpose This study aimed to evaluate 10-year outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in patients with borderline hip dysplasia (BHD) and to determine whether age at surgery (<40 vs ≥40 years) influences long-term patient-reported outcomes (PROs), achievement of clinically meaningful thresholds, and survivorship. Methods A retrospective comparative study was conducted on patients with BHD who underwent primary hip arthroscopy for FAIS with a minimum 10-year follow-up. Patients were stratified by age at surgery (<40 vs ≥40 years) and propensity-matched 1:1 by sex, BMI, and Tönnis grade. PROs, including the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS), were collected preoperatively and at 2-, 5-, and 10-year follow-up. Achievement of the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) was assessed. Failure was defined as revision arthroscopy or conversion to total hip arthroplasty (THA). Kaplan-Meier survivorship analysis was performed. Results Following matching, 40 patients were included (20 ≥40 year, 20 <40 years). Baseline characteristics, radiographic parameters, and operative findings were comparable between groups. At 2 years, younger patients demonstrated higher PROs (mHHS: 87.9 vs 76.0, p = 0.027; NAHS: 89.3 vs 76.0, p = 0.025). Outcomes converged at 5 years but diverged at 10 years, with the <40 cohort demonstrating superior mHHS (94.2 vs 78.5, p = 0.001) and NAHS (92.2 vs 76.4, p = 0.012). Improvements from baseline were greater in the younger cohort for mHHS at 10 years (p = 0.009). MCID achievement was high and similar across groups, but PASS achievement was significantly higher in younger patients (mHHS: 90% vs 45%, p = 0.007; NAHS: 85% vs 50%, p = 0.043). Failure rates were low and comparable (10% vs 15%, p = 1.000), with no differences in time to failure or THA conversion. Conclusion Hip arthroscopy for FAIS in the setting of BHD demonstrates durable 10-year survivorship irrespective of age. However, older patients have inferior long-term functional outcomes and are less likely to achieve PASS. While hip arthroscopy remains a viable option in older patients, surgeons should counsel them on potentially lower functional outcomes despite preserved joint survivorship.