Hip arthroscopy utilization and reoperation rates in Ontario: a population-based analysis comparing different age cohorts

Background: Older age (> 40 yr) and osteoarthritis are negative prognostic variables for hip arthroscopy, but their impact has not been quantified from a population standpoint. The purpose of this study was to perform a population-based analysis of hip arthroscopy utilization and associated 2- and 5-year reoperation rates and complications in different age cohorts. Methods: Administrative databases from Ontario, Canada, were retrospectively reviewed to identify patients aged 18-60 years who underwent hip arthroscopy between 2006 and 2016. Patients were stratified into 2 cohorts: 18-39 and 40-60 years of age. Patients were followed for 2 and 5 years to capture the occurrence of subsequent surgery (repeat arthroscopy or total hip arthroplasty) and postoperative complications. Results: A total of 1906 patients underwent hip arthroscopy, 818 (42.9%) of whom were aged 40-60 years. In the entire cohort, revision surgery occurred in 6.5% and 15.1% of cases at 2 and 5 years, respectively. Revision surgery rates were significantly higher among patients aged 40-60 years at 2 (10.8% v. 3.2%, p < 0.001) and 5 years (22.7% v. 8.2%, p < 0.001) than among those aged 18-39 years. Revision rates were higher among patients aged 50-60 years than among those aged 40-49 years at 2 years (14.3% v. 9.1%, p = 0.027). Complication rates did not differ between cohorts. Regression analysis revealed higher 2- and 5-year odds of secondary surgery in patients aged 40-49 years (odds ratio [ OR] 2.68, 95% confidence interval [CI] 1.70-4.22; OR 2.82, 95% CI 1.87-4.25; p < 0.001), patients aged 50-60 years (OR 4.39, 95% CI 2.67-7.22; OR 3.44, 95% CI 2.11-5.62; p < 0.001) and those with osteo-arthritis (OR 2.41, 95% CI 1.39-4.20; p = 0.002; OR 1.76, 95% CI 1.00-3.09; p = 0.049). Conclusion: Revision surgery rates following hip arthroscopy are significantly higher among older patients and those with concomitant osteo-arthritis. Although the data have limitations, they provide useful information to guide surgical decision-making.