Summary

This randomized, time-to-event analysis with 27-months follow-up demonstrates that for adults between the ages of 18 and 50 with femoroacetabular impingement, arthroscopic osteochondroplasty is associated with a two and a half times lower hazard of reoperation at any point in time compared to arthroscopic lavage.

Abstract

Purpose

The purpose of this study was to assess and compare the effect of arthroscopic osteochondroplasty versus arthroscopic lavage without osteochondroplasty on the time to reoperation in adults aged 18 to 50 with femoroacetabular impingement (FAI) over 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. All included subjects were randomized to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage without osteochondroplasty. The primary 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 (osteochondroplasty versus lavage), with age and impingement severity subtype explored as potential covariates. The results from the Cox model were expressed as a 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 220 patients with FAI were first enrolled in the study. Six patients were later found to be ineligible resulting in 108 total patients included in the osteochondroplasty group and 106 in the lavage group. 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. In 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 to 0.91, p=0.029).

Conclusion

This randomized, time-to-event analysis 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.