No Difference in Total Episode-of-Care Cost Between Staged and Simultaneous Bilateral Total Joint Arthroplasty

Due to concerns about higher complication rates, surgeons debate whether to perform simultaneous bilateral total joint arthroplasty (BTJA), particularly in the higher-risk Medicare population. Advances in pain management and rehabilitation protocols have called into question older studies that found an overall cost benefit for simultaneous procedures. The purpose of this study was to compare 90-day episode-of-care costs between staged and simultaneous BTJA among Medicare beneficiaries.

We retrospectively reviewed a consecutive series of 319 simultaneous primary TJAs and 168 staged TJAs (336 procedures) at our institution between 2015 and 2016. We recorded demographics, comorbidities, readmission rates, and 90-day episode-of-care costs based upon Centers for Medicare and Medicaid Services claims data. To control for confounding variables, we performed a multivariate regression analysis to identify independent risk factors for increased costs.

Simultaneous patients had decreased inpatient facility costs ($19,402 vs $23,025, P < .001), increased post-acute care costs ($13,203 vs $10,115, P < .001), and no difference in total episode-of-care costs ($35,666 vs $37,238, P = .541). Although there was no difference in readmissions (8% vs 9%, P = .961), simultaneous bilateral patients were more likely to experience a thromboembolic event (2% vs 0%, P = .003). When controlling for demographics, procedure, and comorbidities, a simultaneous surgery was not associated with an increase in episode-of-care costs (P = .544). Independent risk factors for increased episode-of-care costs following BTJA included age ($394 per year increase, P < .001), cardiac disease ($4877, P = .025), history of stroke ($14,295, P = .010), and liver disease ($12,515, P = .016).

In the Medicare population, there is no difference in 90-day episode-of-care costs between simultaneous and staged BTJA. Surgeons should use caution in performing a simultaneous procedure on older patients or those with a history of stroke, cardiac, or liver disease.