Is there a gender gap in outcomes after hip arthroscopy for femoroacetabular impingement? Assessment of clinically meaningful improvements in a prospective cohort

OBJECTIVES: Although patients have been found to have significant improvements after hip arthroscopy for femoroacetabular impingement (FAI), prior studies suggest women have worse outcomes compared to men. These previous studies lack comparisons of patient reported outcome (PRO) scores based on gender with respect to clinical significance measurements, including the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS). Therefore, the purpose of this study is to evaluate outcomes following hip arthroscopy for FAI based on patient gender by prospectively assessing changes in PRO scores, MCID, and PASS. METHODS: Women and men undergoing hip arthroscopy for FAI were prospectively enrolled and preoperative radiographic and intra-operative findings were collected. The cohort was stratified based on self-identified patient gender so the term gender as well as the terms women and men were used to describe the patients as opposed to sex and the terms female and male. Patients completed the following PRO surveys before surgery and 2-years postoperatively: modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (HOOS), and the 12-Item Short Form Health survey (SF-12). Mean scores and the percentage of patients reaching MCID and PASS were analyzed. An a priori power calculation was performed which determined 42 hips in each group were needed to adequately power the study to 95%. RESULTS: A total of 131 hips, from 72 women and 59 men were included. The mean ± SD age for women and men was 34.2 ± 9.5 vs 35.8 ± 10.3 years, respectively; P= .347 and body mass index (BMI) of 24.9 ± 4.4 vs 25.5 ± 3.3 kg/m2, respectively; P= .379. Women had smaller preoperative alpha angles (59.1 vs 63.7, respectively; P< 0.001) and lower acetabular cartilage injury grade (6.9% vs 22.0% with grade 4 injury, respectively; P= 0.013). Both women and men achieved equivalent significant improvements in PRO scores after surgery (PRO scores increased 18.4 to 45.1 points for mHHS and HOOS). Women and men reached PASS for mHHS at similar rates (76.4% and 77.2%, respectively; P=0.915). MCID was also achieved at similar rates between women and men for all scores (ranged 61.4% to 88.9%) except HOOS-ADL in which a higher percentage of women reached MCID compared to men (79.2% vs 62.7%, respectively; P= .037). Additional stratification by age group using the median cohort age of 34 showed no significant differences in PRO improvement based on age group for each gender. CONCLUSIONS: Women can achieve clinically meaningful improvements in patient reported outcomes scores after hip arthroscopy for FAI. Compared to men, women demonstrated equivalent high rates of achieving MCID and PASS at 2 years following surgery.