Staging Total Hip and Knee Arthroplasty Procedures Within 90 Days Increases Costs in Bundled Payment Programs.

BACKGROUND

Under current Medicare bundled payment programs, when a patient undergoes a subsequent elective procedure within the 90-day episode-of-care, the first procedure is excluded from the bundle and a new episode-of-care initiated. The purpose of this study was to determine if staging bilateral total hip (THA) and total knee arthroplasty (TKA) procedures within 90 days have an effect on bundled episode-of-care costs.

METHODS

We reviewed a consecutive series of Medicare patients undergoing staged primary THA and TKA from 2015-2019. Patients who underwent a prior procedure within 90 days were compared to those who had undergone a procedure 90-120 days prior. We then performed a multivariate analysis to identify the independent effect of staging timeframe on costs and outcomes.

RESULTS

Of the 136 patients undergoing a staged bilateral THA or TKA, 48 patients underwent staged procedures within 90 days (35%) and 88 patients between 91-120 days (65%). There were no significant differences observed for demographics, comorbidities, complications, readmissions, or discharge disposition (all P > .05). Patients undergoing a staged procedure within 90 days had increased episode-of-care costs by $2021 (95% CI $11-$4032, P = .049), increased postacute care costs by $2019 (95% CI $66-$3971, P < .001), and reduced per-patient margin by $2868 (95% CI-$866-$4869, P = .005).

DISCUSSION

Patients undergoing staged bilateral THA or TKA within 90 days have increased episode-of-care costs compared to those undergoing a staged procedure from 91-120 days. Since patients may still not be fully recovered from the first procedure, CMS should address the inappropriate allocation of costs to ensure institutions are not penalized.