Medicare Bundled Payment Model for Total Ankle Arthroplasty
Authors: Corr Daniel O. , Riddhi Gandhi , O'Neil Joseph T. , Raikin Steven M. , Shakked Rachel J. 
Published: January 2022

Category: Ankle; Other Introduction/Purpose: Total ankle arthroplasty (TAA) is included in the Centers of Medicare and Medicaid Services' (CMS) Bundled Payments for Care Improvement (BPCI) initiative for lower extremity joint replacements. This model has been demonstrated to be for total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, there remains concern that the model underestimates expected costs for TAA due to the unique healthcare needs of TAA patients including higher implant costs, longer procedures, and an increased demand for postoperative acute care services due to non-weightbearing. The purpose of this study was to analyze the breakdown of costs associated with inpatient and outpatient care and assess the difference between Medicare beneficiary reimbursements and actual costs for the episode of care. Methods: An IRB-approved retrospective review was conducted of patients with Medicare who underwent TAA between July 2014 and June 2018. The surgeries were performed at seven facilities affiliated with a singular institution hospital system. Patients undergoing TAA in this time period were identified using an institutional arthroplasty database and were eligible for study. Of 99 patients who met this criterion, financial data was available for 72. Demographics including age, gender, BMI, and comorbidities were collected via chart review. Episode start and end dates, first post-acute care discharge destination, and total episode costs were recorded. Total episode cost was subdivided into inpatient facility cost, surgeon fees, and post-acute care discharge costs (inpatient rehab facility costs, skilled nursing facility expenses, or home health aide fees). Patients were stratified into two groups based on 90-day costs of care, a 'positive group' not exceeding the bundled payment allocation and a 'negative group' which did exceed. Results: No statistically significant difference was found among demographics between the positive and negative patient groups. Average group age was 70.5 years and 72.9 years, respectively, and both groups had average BMI of 29.3 kg/m2. Age-adjusted Charlson Comorbidity Index was 3.35 for the positive group and 3.40 for the negative group. Total episode costs were 50% higher in the negative group compared to the positive group ($31,462 vs. $15,845). The total post discharge costs for the negative group were $17,912 which is significantly higher than those of the positive group ($2,502) (P<0.001). Thirteen patients (18.1%) attended skilled nursing facilities, and 12 of these patients exceeded the allocated budget. Average SNF cost was $13,089, which nearly matched the entire inpatient cost (facility + surgeon fees) of $13,400. Home health aide requirement was significant at 39% (n=28), and 15 of these patients (54%) also came in over budget. Conclusion: Results suggest that there is a considerable possibility for patients undergoing TAA to have post-acute care requirements that drive cost over budget, including admittance to skilled nursing facilities and home health aide, likely sue to the added necessity for extended immobilization in an older patient population. Such parameters should be factored into the BPCI reimbursement model for TAA.