When Do Patients Improve After Hip Arthroscopy for Femoroacetabular Impingement? A Prospective Cohort Analysis.

BACKGROUND: Hip arthroscopy for femoroacetabular impingement (FAI) has been shown to improve patient outcomes, especially for returning to sport. Although previous studies often evaluated outcomes 2 years after hip arthroscopy, there has been no analysis of the progression of patient improvement over time or with respect to achieving the minimal clinically important difference (MCID).

HYPOTHESIS/PURPOSE: The purpose was to prospectively evaluate changes in patient-reported outcome (PRO) scores during the first 2 years after hip arthroscopy for FAI and to analyze when the MCID is achieved. It was hypothesized that clinically significant changes will be reached by 1 year after surgery.

STUDY DESIGN: Case series; Level of evidence, 4.

METHODS: Patients undergoing hip arthroscopy for FAI were prospectively enrolled, and they completed the 12-Item Short Form Health survey (SF-12), modified Harris Hip Score, and Hip disability and Osteoarthritis Outcome Score (HOOS) at preoperative baseline and 3 months, 6 months, 1 year, and 2 years after surgery. Mean scores and the percentage of patients reaching the MCID at each time point were analyzed via analysis of variance and Cochrane-Armitage trend tests.

RESULTS: A total of 129 hips from 122 patients were evaluated, revealing significant improvements after hip arthroscopy for FAI (PRO scores increased 19 to 45 points) with 95.8%, 93.6%, and 84.8% of patients achieving the MCID for HOOS-Sports, HOOS-Quality of Life (QoL), and HOOS-Pain, respectively, at 2-year follow-up. Analysis of PRO change showed that for all scores, the greatest improvement occurred from presurgery to postoperative 3 months, with lesser improvements at subsequent 6-month, 1-year, and 2-year time points ( P < .001). The SF-12 physical component score, HOOS-Sports, and HOOS-QoL continued to show statistically significant improvements through 2 years, while other scores plateaued after 3 months. The percentage of patients achieving the MCID for HOOS-Sports, HOOS-QoL, and HOOS-Pain continued to increase over 2 years, but the percentage achieving the MCID did not increase after 3 months for all other scores.

CONCLUSION: Hip arthroscopy for FAI yields significant improvements in patient outcomes within 2 years of surgery. The majority of improvement occurs within 3 months after surgery, but certain outcomes, such as returning to sport, QoL, and pain, can continue to improve through 2 years.