Outcome Trends After Hip Arthroscopy for Femoroacetabular Impingement: When Do Patients Improve?

To determine when patients reach critical thresholds of clinical improvement after hip arthroscopy for femoroacetabular impingement (FAI) using previously defined cutoffs for the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) and to identify risk factors for prolonged recovery.Consecutive patients with a diagnosis of FAI who underwent unilateral hip arthroscopy between January 2010 and January 2015 with at least 2 years of clinical follow-up were studied. The modified Harris Hip Score was collected prospectively at 6 consecutive time points. The number of patients reaching the MCID and PASS at each time point was determined.During the study period, 340 consecutive hip arthroscopies were performed in 316 patients with a mean final follow-up period of 50 months (range, 29-84 months). The mean modified Harris Hip Score and percentage of patients reaching the MCID and PASS increased at each time point. At 2 years, 271 patients (93%) surpassed the MCID and 212 patients (73%) achieved the PASS. Female sex, age of 40 years or older, and body mass index of 30 or greater were associated with lower rates of achieving the MCID and PASS at set time points. Patients undergoing labral repair had superior PASS rates at 3 months and beyond than patients undergoing labral debridement alone. Patients who did not achieve the PASS by 3 months were more likely to require reoperation.Hip arthroscopy for FAI results in increased patient-reported outcome measures at interval follow-up. Most patients reach critical thresholds of minimal and satisfactory clinical improvement. Patients who are female, older, or obese or who undergo labral debridement alone are less likely to reach these milestones at major time intervals. Patients who do not reach the PASS by 3 months are more likely to require reoperation.Level IV, therapeutic case series.