Conversion Total Hip Arthroplasty in the Era of Bundled Care Payments: Impacts on Costs of Care

BackgroundConversion hip arthroplasty is defined as a patient who has had prior open or arthroscopic hip surgery with or without retained hardware that is removed and replaced with arthroplasty components. Currently, it is classified under the same diagnosis-related group as primary total hip arthroplasty (THA); however, it frequently requires a higher cost of care.MethodsA retrospective study of 228 conversion THA procedures in an orthopaedic specialty hospital was performed. Propensity score matching was used to compare the study group to a cohort of 510 primary THA patients by age, body mass index, sex, and American Society of Anesthesiologists score. These matched groups were compared based on total costs, implants used, operative times, length of stay (LOS), readmissions, and complications.ResultsConversion THA incurred 25% more mean total costs compared to primary THA (P < .05), longer lengths of surgery (154 versus 122 minutes), and hospital LOS (2.1 versus 1.56 days). A subgroup analysis showed a 57% increased cost for cephalomedullary nail conversion, 34% increased cost for sliding hip screw, 33% for acetabular open reduction and internal fixation conversion, and 10% increased costs in closed reduction and percutaneous pinning conversions (all P < .05). There were 5 intraoperative complications in the conversion group versus none in the primary THA group (P < .01), with no statistically significant difference in readmissions.ConclusionConversion THA is significantly more costly than primary THA and has longer surgical times and greater LOS. Specifically, conversion THA with retained implants had the greatest impact on cost.