The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome

Background: One of the reported goals of hip preservation surgery is to prevent or delay the onset of osteoarthritis. This includes arthroscopic surgery to manage Femoroacetabular Impingement (FAI) Syndrome. The purpose of this study was to describe the prevalence of clinically-diagnosed hip OA within 2years after hip arthroscopy for FAI syndrome, and 2) determine which variables predict a clinical diagnosis of OA after arthroscopy. Methods: Observational analysis of patients undergoing hip arthroscopy between 2004 and 2013, utilizing the Military Health System Data Repository. Individuals with prior cases of osteoarthritis were excluded. Presence of osteoarthritis was based on diagnostic codes rendered by a medical provider in patient medical records. Adjusted odds ratios (95% CI) for an osteoarthritis diagnosis were reported for relevant clinical and demographic variables. Results: Of 1870 participants in this young cohort (mean age 32.2 years), 21.9% (N=409) had a postoperative clinical diagnosis of hip osteoarthritis within 2 years. The 3 significant predictors in the final model were olderage (OR=1.04; 95%CI=1.02, 1.05), male sex (OR=1.31; 95%CI=1.04, 1.65), and having undergone an additional hip surgery (OR=2.33; 95% CI=1.72, 3.16). Military status and post-surgical complications were not risk factors. Conclusion: A clinical diagnosis of hip osteoarthritis was found in approximately 22% of young patients undergoing hip arthroscopy in as little as 2 years. These rates may differ when using alternate criteria to define OA, such as radiographs, and likely underestimate the prevalence. A more comprehensive approach, considering various criteria to detect OA will likely be necessary to accurately identify the true rates. Females were at lower risk, while increasing age and multiple surgeries increased the risk for an OA diagnosis. OA onset still occurs after hip preservation surgery in a substantial number of individuals within 2 years. This should be considered when estimating rates of disease prevention after surgery. Prospective trials with sound methodology are needed to determine accurate rates and robust predictors of osteoarthritis onset after hip preservation surgery.