Paper 25: The Effect of Osteochondroplasty on Time to Reoperation after Arthroscopic Management of Femoroacetabular impingement

OBJECTIVES: The purpose of this study was to assess and compare the effect of 1) arthroscopic osteochondroplasty with or without labral repair versus 2) arthroscopic lavage with or without labral repair on the time to reoperation in adults aged 18 to 50 with femoroacetabular impingement (FAI) over the 27-months post-operative using a time-to-event analysis. METHODS: Using the comprehensive dataset from the multinational Femoroacetabular Impingement Randomized Controlled Trial (FIRST), all reoperations were identified until 27-months post-operative. Subjects were randomized to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage with or without labral repair. The analysis was conducted using a Cox proportional-hazards model, with the percentage of patients with a reoperation analyzed in a time-to-event analysis as the outcome. The independent variable was the procedure, with age and impingement subtype explored as potential covariates. The effects from the Cox model were expressed as the hazard ratio (HR), corresponding 95% confidence interval (CI) and the associated p-value. All tests were two-sided with an alpha level of 0.05. RESULTS: A total of 108 patients in the osteochondroplasty group and 106 in the lavage group were included. The mean age of the patients included in the study was 36.0 (SD=8.5) years. Overall, a total of 27 incident reoperations were identified within 27 months of follow-up for an incidence rate of 6.0 per 100 person years. Within the osteochondroplasty group a total of 8 incident reoperations were identified for incidence rate of 3.4 per 100 person years while within the lavage group, a total of 19 incident reoperations were identified for an incidence rate of 8.7 per 100 person years. The hazard of reoperation for patients undergoing osteochondroplasty is 40% that of patients undergoing lavage (HR=0.40,95% CI=0.17-0.91,p=0.029). CONCLUSIONS: This, time-to-event analysis with 27-months follow-up demonstrates that for adults between the ages of 18 and 50 with FAI, arthroscopic osteochondroplasty is associated with a 2.5-fold decrease in the hazard of reoperation at any point in time compared to arthroscopic lavage.