Reducing surgical trays to cut both carbon emissions and costs in total knee arthroplasty.

Background and purpose:  Operating theatres are significant contributors to hospital waste and carbon emissions. In total knee arthroplasty (TKA), the number of surgical trays - and thus the carbon footprint - may be reduced by accurately estimating the prosthesis size preoperatively. We aimed to develop a predictive model to improve preoperative estimation of femoral prosthesis size and reduce the number of trays used in primary TKA.

Methods:  We retrospectively reviewed all primary TKA procedures performed between January 2012 and November 2022 at a single teaching hospital in the Netherlands. Using repeated hold-out cross-validation, we developed a prediction model based on routinely available demographic and anthropometric data to predict femoral component size. Rather than minimizing instruments per tray, our strategy focused on reducing the total number of trays. We used the created prediction model in combination with frequency data from our implanted TKAs to tailor surgical trays accordingly. We performed a post-hoc analysis to estimate the carbon emission cut and cost reduction.

Results:  The best-performing models utilized overlapping tray size ranges, with a practical limit of 3 sizes per tray. The final model predicted the appropriate size range with 97.4% accuracy. This enabled the elimination of 1 tray from the standard surgical setup, reducing total tray use by 11%.

Conclusion:  Accurate preoperative prediction of femoral prosthesis size facilitates surgical tray reconfiguration. We were able to reach an 11% reduction in total trays used with an estimated 1.03 kgCO2eq and a €29.6 cost reduction per reduced tray.