Frisch NB, Keating TC, Calkins TE, et al. - This research was undertaken to correlate intraoperative and postoperative variables including procedure duration, components, length of stay, readmission, complications, and reoperations among patients undergoing conversion total knee arthroplasty (TKA). Primary TKA from a single-surgeon database distinguished 130 individuals with prior knee surgery to form a “conversion” cohort. For comparison, one-to-one matching distinguished 130 individuals of similar age, American Society of Anesthesiologists score, body mass index, and gender without prior knee surgery. Researchers compared perioperative and 90-day postoperative variables between patients with and without prior surgery, within the conversion group based on the type of prior surgery, and whether the prior surgery was bony or soft tissue. The findings revealed that individuals undergoing conversion TKA needed elevated resource utilization, especially individuals with a prior osteotomy or fracture. This study's findings demonstrate that policymakers should recognize these variables, as they did in conversion THA, in adding code to account for elevated case complexity and resource utilization.