What is the Value of a Balanced Total Knee Arthroplasty? Getting It Right the First Time

Instability is a leading cause of early failure following total knee arthroplasty (TKA). Enabling technologies can improve accuracy, but their clinical value remains undetermined. The purpose of this study was to determine the value of achieving a balanced knee joint at the time of TKA.

A Markov model was developed to determine the value from reduced revisions and improved outcomes associated with TKA joint balance. Patients were modeled for the first 5 years following TKA. The threshold to determine cost-effectiveness was set at an incremental cost effectiveness ratio of $50,000/quality-adjusted life year (QALY). A sensitivity analysis was performed to evaluate the influence of QALY improvement (ΔQALY) and Revision Rate Reduction on additional value generated compared to a conventional TKA cohort. The impact of each variable was evaluated by iterating over a range of ΔQALY (0 to 0.046) and Revision Rate Reduction (0% to 30%) and calculating the value generated while satisfying the incremental cost effectiveness ratio threshold. Finally, the impact of surgeon volume on these outcomes was analyzed.

The total value of a balanced knee for the first 5 years was $8,750, $6,575, and $4,417 per case, for low, medium, and high-volume surgeons, respectively. Change in QALY accounted for greater than 90% of the value gain with a reduction in revisions making up the rest in all scenarios. The economic contribution of revision reduction was relatively constant regardless of surgeon volume ($500/case).

Achieving a balanced knee had the greatest impact on ΔQALY over early revision rate. These results can help assign value to enabling technologies with joint balancing capabilities.