EP3.41 Female Sex Increases Susceptibility to the Negative Effects of Elevated Body Mass Index and Advanced Age on 15-Year Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

Abstract

Abstract Purpose To evaluate the association of sex, body mass index (BMI), and age with patient-reported outcomes (PROs) at 15-year follow-up after primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and to determine whether sex modifies the effects of BMI and age on long-term outcomes. Methods A retrospective analysis was performed of a prospectively collected database of patients who underwent primary hip arthroscopy for FAIS by a single surgeon between September 2009 and February 2012. Patients with at least 15 years of follow-up were included. PROs, including the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS), were collected at baseline and final follow-up. Patients were stratified by sex, BMI, and age. Outcomes included final PRO scores, change in scores (Δ), achievement of the minimal clinically important difference (MCID), and Patient Acceptable Symptom State (PASS). Nonparametric testing (Kruskal–Wallis) and Fisher’s exact tests were used for subgroup analyses. Multivariable linear regression, including interaction terms between sex and BMI and between sex and age, was performed to identify independent predictors of 15-year outcomes. Results A total of 93 hips (55 female, 38 male) were included with a mean follow-up of 15 ± 0.7 years. Male and female patients were comparable at baseline in age, BMI, baseline PROs, and most radiographic parameters. Both mHHS and NAHS demonstrated significant improvement from baseline to 15-year follow-up (P < .001). Among female patients, increasing BMI was associated with progressively worse 15-year outcomes, including mHHS (P = .003), NAHS (P = .025), ΔmHHS (P < .001), and ΔNAHS (P = .002). Increasing age was similarly associated with worse outcomes in females, including NAHS (P = .008), ΔmHHS (P = .009), and ΔNAHS (P = .003). In contrast, among male patients, neither BMI nor age was associated with 15-year PROs (all P > .05). On multivariable regression, higher BMI was independently associated with worse 15-year mHHS (β = −2.38, P < .001). A significant interaction between BMI and sex was observed (β = +1.66, P = .032), indicating that the negative effect of increasing BMI was significantly attenuated in male patients compared with females. Higher baseline scores were predictive of improved outcomes (β = 0.38, P = .001). Conclusion The negative effects of elevated BMI and advanced age on outcomes after hip arthroscopy for FAIS persist at 15-year follow-up and disproportionately affect female patients. These findings suggest a durable, sex-specific vulnerability with important implications for patient selection, counseling, and long-term prognosis.