Increased Early Mortality in Bilateral Simultaneous TKA Using Conventional Instrumentation Compared with Technology-Assisted Surgery: A Study of 34,908 Procedures from a National Registry.

Abstract

Controversy exists regarding the safety of bilateral simultaneous total knee arthroplasty (BSTKA). When conventional instrumentation is used, the increased fat emboli that result from the insertion of intramedullary rods may increase the risk of perioperative complications. We hypothesized that the use of technology-assisted instrumentation (avoiding intramedullary involvement) would be associated with a lower rate of early postoperative death compared with the use of conventional instrumentation. We compared the 30 and 90-day rates of mortality following BSTKA performed with conventional versus technology-assisted instrumentation from 2003 to 2019, with use of data from a large national registry. Firth logistic regression analysis was utilized, adjusting for age, sex, and procedure year for all BSTKAs performed during the study period. For procedures performed from 2015 to 2019, odds ratios were additionally adjusted for American Society of Anesthesiologists physical status classification and body mass index. A total of 34,908 BSTKAs were identified. The proportion of cases utilizing technology-assisted instrumentation increased over the study period. The odds ratio of death within 30 days after technology-assisted BSTKA, adjusted for age, sex, and procedure year, was 0.26 (95% confidence interval [CI], 0.08 to 0.83; p = 0.02). The odds ratio, adjusted for age, sex, procedure year, American Society of Anesthesiologists classification, and body mass index, was 0.26 (95% CI, 0.09 to 0.74; p = 0.01). The corresponding odds ratios for 90-day mortality were 0.25 (95% CI, 0.09 to 0.72; p = 0.01) and 0.26 (95% CI, 0.10 to 0.67; p = 0.005), respectively. Technology-assisted BSTKA was associated with a significant reduction in early mortality compared with the use of conventional instrumentation. This difference may be explained by the reduced fat emboli associated with technology-assisted BSTKA and is likely to be clinically important on a population scale. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.