Clinical Outcomes and Reoperation Rates After Hip Arthroscopy in Female Athletes With Low Versus Normal Body Mass Index: A Propensity-Matched Comparison With Minimum 2-Year Follow-up

The effect of low body mass index (BMI) on outcomes in female athletes is unknown.(1) To report minimum 2-year patient-reported outcomes and return to sports for high-level female athletes with low BMI undergoing hip arthroscopy for femoroacetabular impingement syndrome and (2) to compare results with those of a propensity-matched control group of high-level female athletes with a normal BMI.Cohort study; Level of evidence, 3.Data were collected on all professional, collegiate, and high school female athletes who had a low BMI and underwent primary hip arthroscopy between September 2009 and March 2017 at our institute. Return-to-sports status and minimum 2-year patient-reported outcomes were collected for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and visual analog scale (VAS) for pain. The percentage of patients achieving the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and maximum outcome improvement satisfaction threshold (MOIST) was also recorded. These patients were propensity matched to high-level female athletes with a normal BMI for comparison.A total of 21 high-level female athletes (25 hips) with a mean ± SD follow-up of 58.9 ± 31.5 months were included. They demonstrated significant improvement from preoperatively to latest follow-up for the mHHS, Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and VAS (P < .001). When outcomes were compared with those of the control group, female athletes with low BMI demonstrated lower rates of achieving the MCID for the mHHS (54.5% vs 77.4%; P = .041), PASS for the International Hip Outcome Tool-12 (45.5% vs 72.6%; P = .022), and MOIST for the VAS (31.8% vs 56.5%; P = .047). There were no other significant differences in the rate of achieving the MCID, PASS, or MOIST between the groups (P > .05). Female athletes with low BMI also had higher rates of revision when compared with the control group (27.2% vs 10.6%; P = .049), but there were comparable return-to-sports rates (75.0% vs 74.5%; P > .05).High-level female athletes with low BMI undergoing primary hip arthroscopy for femoroacetabular impingement syndrome demonstrated significant improvement in patient-reported outcomes and acceptable rates of return to play. When compared with a control group with normal BMI, they exhibited higher rates of revision and lower rates of achieving the MCID for the mHHS, PASS for the International Hip Outcome Tool-12, and MOIST for the VAS.