Lonner JH, Goh GS, Sommer K, et al. - This study was undertaken to investigate the economic effect of instrument tray optimization in total joint arthroplasty. Researchers examined 35 randomly selected elective primary total knee arthroplasty and total hip arthroplasty performed by four fellowship-trained surgeons. Surgeons distinguished redundant or underutilized instruments and agreed upon the fewest number needed for each tray using Lean methodology. The results of this study demonstrate that lean methodology can be applied to eliminate redundant or underutilized instruments in total joint arthroplasty, improving surgical effectiveness and generating substantial cost savings.