Paper 48: Elite Female Athletes Demonstrate Greater Improvement in Patient Reported Outcome Scores and Equal Rate of Return to Sport Compared to Elite Male Athletes After Hip Arthroscopy: A Sex-Based Comparison in Professional and Collegiate Athletes *ACCEPTED TO AJSM*

Objectives: (1) To report minimum 2-year patient reported outcome scores (PROs) and return to sport for elite female athletes undergoing hip arthroscopy for femoroacetabular impingement (FAI) and (2) to compare clinical results with a matched control group of elite male athletes. Methods: Data on all consecutive female athletes who underwent primary hip arthroscopy performed by the senior author (X.X.X.) between March 2009 and July 2018 were collected. Patients were considered eligible if they underwent hip arthroscopy for labral tears or FAI and participated in collegiate or professional athletics within 1 year of surgery. Minimum 2-year PROs were collected for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sport Specific Subscale (HOS-SSS), visual analog scale (VAS) for pain, and RTS status. The percentage of patients achieving minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) were also recorded. These patients were then matched to elite male athletes for comparison. Results: Seventy-three female athlete hips were included with a mean follow-up of 65.1 ± 27.9 months. They demonstrated significant improvement from preoperative to latest follow-up for mHHS, NAHS, HOS-SSS, and VAS (P <.05). When outcomes were compared to a control group of male athletes, female athletes demonstrated lower preoperative scores, similar postoperative scores, and significantly greater magnitude of improvement (delta value) for mHHS, NAHS, and VAS. Female athletes also achieved MCID at higher rates than male athletes for HOS-SSS (85.1% vs 70.0%, P =.035) and NAHS (79.1% vs 62.9%, P =.037). RTS rates were similar between the two groups (Females: 67.1%, Males: 67.1%, P > 0.999). Conclusions: Elite female athletes undergoing primary hip arthroscopy for FAI demonstrated significant improvement in PROs and high rates of return to play, which were similar to a matched group of male athletes. Female athletes exhibited greater improvement in PROs (mHHS, NAHS, VAS) and achieved MCID (HOS-SSS, NAHS) at higher rates when compared to a control cohort of male athletes. Figure 1. Patient Selection Flowchart Figure 2. Return to sport rate comparison between males and females. (Lifestyle transition: did not return to sport due to a lifestyle transition; Hip pain: did not return to sport due to hip pain) Table 1. Rate of MCED and PASS achievement between the male and female cohorts at minimum 2 years. [ABSTRACT FROM AUTHOR]