Conversion Total Knee Arthroplasty is Associated with Increased Post-Acute Care Costs

Area of Science:

• Orthopedics
• Health Economics
• Health Services Research

Background:

• Alternative payment models aim to reduce costs in total knee arthroplasty (TKA) while maintaining quality.
• Concerns exist about resource utilization for patients in bundled payment arrangements.
• This study investigates cost differences between conversion and primary TKA.

Purpose of the Study:

• To determine if conversion total knee arthroplasty (TKA) incurs higher costs than primary TKA.
• To identify factors contributing to increased costs and resource utilization in conversion TKA.
• To inform risk adjustment strategies in alternative payment models for TKA.

Main Methods:

• Retrospective review of Medicare and private insurer claims for TKA patients (2015-2016).
• Comparison of 90-day post-acute care costs between primary and conversion TKA cohorts.
• Multivariate regression analysis to identify independent risk factors for costs, complications, and readmissions.

Main Results:

• Conversion TKA (23% of cases) showed higher post-acute costs in commercially insured patients ($4714 vs $3759, P=.034).
• Among Medicare patients, prior ligament reconstruction increased costs ($1917, P=.036).
• Conversion TKA independently predicted readmissions (OR 1.46), and prior open procedures increased complications (OR 2.41).

Conclusions:

• Conversion TKA is linked to elevated 90-day post-acute care costs and resource use, especially after open knee procedures.
• Lack of risk adjustment in payment models may financially discourage surgeons from performing complex conversion TKA.
• Ensuring appropriate risk adjustment is crucial for maintaining quality arthroplasty care under new payment structures.