PURPOSE: The purpose of this study was to evaluate patient-reported outcomes (PROs) and survivorship in obese patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at 10-year follow-up. METHODS: A retrospective review was conducted of patients who underwent arthroscopy for FAIS from 2010-2013. Patients were assessed at baseline, 1 month, 6 months, 1-, 2-, 5-, and 10 years using the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS). Patients were categorized based on BMI into normal, overweight, and obese cohorts. Minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) were calculated for both PROs. Improvements from baseline were analyzed and differences between groups were evaluated while controlling for age. Survival to revision surgery was assessed with Kaplan-Meier survival curves. RESULTS: 144 patients (65.2% female) with a mean age of 38.8 ± 13.0 years and an average follow-up of 11.6 (range 10.0-13.8) years were included, and categorized into normal weight (59.7%), overweight (26.4%), and obese (13.9%). All groups showed significant improvement in PROs at 10 years compared to baseline (p=0.007). Obese patients had lower postoperative scores (mHHS: 72.8 vs. 90.1, p=0.009
NAHS: 68.4 vs.. 88.6, p=0.003) and improvement in scores from baseline (mHHS: 23.4 vs. 37.7, p=0.013
NAHS: 18.4 vs. 40.0, p=0.004) at 10-year follow-up, as well as lower achievement of mHHS PASS (60.0% vs 87.2%, p=0.015), NAHS PASS (50.0% vs. 89.5%, p<
.001) and NAHS MCID (70.0% vs. 93.0%, p=0.008). Obese patients also had a higher rate of conversion to THA (17.4% vs 3.3%, p=0.012). The overall complication rate was 4.2% compared to 10% in the obese group, with obese patients experiencing a superficial infection more frequently (p=0.002). CONCLUSION: Although obese patients still have significantly improved outcomes compared to baseline, at 10-year follow-up they have inferior outcomes compared to nonobese patients and higher rates of conversion to THA. LEVEL OF EVIDENCE: Level III, retrospective comparative study.