Nicholas A Bedard, Andrew J Pugely, Kyle R Duchman, Robert W Westermann, Yubo Gao, John J Callaghan

Rates of hip arthroscopy have been on an exponential rise. The purpose of this study was to evaluate the rate and timing of subsequent total hip arthroplasty (THA) after hip arthroscopy and identify if rates of THA differed based on age, diagnosis of osteoarthritis, or arthroscopic procedure performed. The Humana administrative claims data set was reviewed from 2007 to 2014 for all patients undergoing hip arthroscopy. Patients were identified using Current Procedural Terminology codes and laterality modifiers. Patients were tracked over time for the occurrence of an ipsilateral THA. Rates and timing of subsequent THA were then determined. Subgroup analysis was performed based on patient age and hip arthroscopy procedure performed. In total, 1577 patients underwent hip arthroscopy. Tracking of patients revealed 84 (5.3%) patients that had an ipsilateral THA after hip arthroscopy during the follow-up period. Of the subsequent THA, 35.7% occurred within 6 months of hip arthroscopy and 83.3% had occurred within 18 months. Hundred percent of subsequent THAs occurred within 48 months of initial hip arthroscopy. Patients aged ≥50 years at the time of hip arthroscopy had a higher odds of conversion to THA (odds ratio: 3.2 [2.05-5.01], P < .001) as did those with chondroplasty included in their procedure (odds ratio: 3.5 [2.10-5.84], P < .001). Approximately 5% of hip arthroscopies went on to require a subsequent THA, and all conversions to THA occurred within 4 years. These data suggest that when hip arthroscopy fails, it does so relatively soon after the procedure. These results provide a needed understanding of rates and timing of THA after hip arthroscopy.