A Randomized Trial Investigating the Cost-Utility of Patient-Specific Instrumentation in Total Knee Arthroplasty in an Obese Population

Background: Patient-specific instrumentation (PSI) has been introduced in total knee arthroplasty (TKA) with the goal of increased accuracy of component positioning by custom fitting cutting guides to the patient's bony anatomy. A criticism of this technology is the associated cost. The purpose of this randomized controlled trial was to determine the cost-utility of PSI compared with standard of care (SOC) instrumentation for TKA in an obese population. Methods: Patients with body mass index greater than 30 with osteoarthritis and undergoing primary TKA were randomized to SOC or PSI. Patients completed a health care resource use diary and the EuroQol-5D at three, six, nine, and 12 months and the Western Ontario and McMaster Universities Osteoarthritis Index at three and 12 months postsurgery. We performed cost-utility and costeffectiveness analyses from public health care payer and societal perspectives. Results: One hundred seventy-three patients were included in the analysis with 86 patients randomized to PSI and 87 to SOC. PSI was dominated (more costly and less effective) by SOC from a health care payer perspective. From a societal perspective, an incremental cost-utility ratio was calculated at $11,230.00 per quality-adjusted life year gained, which is cost-effective at a willingness to pay threshold of $50,000. Net benefit analyses found PSI was not significantly cost-effective at any willingness to pay value from either perspective. Conclusion: Our results suggest that widespread adoption of PSI may not be economically attractive or clinically indicated. Future considerations are to compare long-term clinical outcomes and radiographic alignment between the groups. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In total knee arthroplasty for obese patients, patient-specific instrumentation (PSI) was found to be more costly and less effective compared to standard of care (SOC) from a healthcare payer perspective. However, from a societal perspective, PSI had an incremental cost-utility ratio of $11,230.00 per quality-adjusted life year gained, which was considered cost-effective.