Abstract
BACKGROUND: The risk of subsequent joint replacement following an index joint replacement for osteoarthritis and the association of this risk with demographic and patient-specific factors are not well understood. The purpose of this study was to determine how demographic and other patient-specific factors are associated with the risk of subsequent joint replacement in the contralateral or a different joint following an index joint replacement for osteoarthritis. METHODS: The Healthcare Cost and Utilization Project (HCUP) State Inpatient Database (SID) of New York was used to identify the first (primary) total hip arthroplasty (THA), total knee arthroplasty (TKA), or total shoulder arthroplasty (TSA) and the risk of subsequent joint replacement in the contralateral or a different joint over 5 to 8 years. The association of demographic and other patient-specific factors with subsequent joint replacement was assessed via multivariable Cox proportional hazards modeling. We also investigated the time between the index and subsequent joint replacement. RESULTS: Of 85,616 patients, 20,223 (23.6%) underwent a subsequent replacement of the contralateral joint within 5 to 8 years (median, 343 days) after the index joint replacement. The strongest predictors were obesity (adjusted hazard ratio [HR] = 1.28; p < 0.001) and index TKA compared with THA (1.72; p < 0.001). A total of 3,197 patients (3.7%) underwent a subsequent replacement of a different joint within 5 to 8 years (median, 876 days) after the index joint replacement. The strongest predictors were obesity (adjusted HR = 1.41; p < 0.001) and index TSA compared with THA (adjusted HR = 2.52; p < 0.001). CONCLUSIONS: There is a relatively high risk of subsequent replacement of the contralateral joint and a relatively low risk of subsequent replacement of a different joint within 5 to 8 years after an index THA, TKA, or TSA. Obesity was associated with a higher risk of subsequent replacement of the contralateral joint or a different joint. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.