Increased Postoperative Glucose Variability Is Associated with Adverse Outcomes Following Total Joint Arthroplasty.

BACKGROUND: Increased glucose variability during hospitalization has been associated with a longer length of stay in the hospital and a higher mortality rate following non-orthopaedic surgical procedures. Our aim was to investigate the association between glucose variability and postoperative complications following total joint arthroplasty.

METHODS: We analyzed data on 21,487 patients who had undergone total hip arthroplasty (THA) or total knee arthroplasty (TKA) at a single center from 2001 to 2017. Patients with a minimum of 2 postoperative glucose values per day or >3 values overall were included in the study. Glucose variability was assessed using a coefficient of variation. Adverse outcomes included an increased length of stay in the hospital, 90-day mortality, reoperations, periprosthetic joint infection, and surgical site infection. Periprosthetic joint infection was defined using the Musculoskeletal Infection Society criteria.

RESULTS: The final cohort included 2,360 patients who had undergone THA and 2,698 who had undergone TKA; 1,007 (19.9%) had diabetes. Higher glycemic variability was associated with an increased length of stay, 90-day mortality, periprosthetic joint infection, and surgical site infection. Adjusted analysis indicated that for every 10-percentage-point increase in the coefficient of variation, the length of stay increased by 6.1% (95% confidence interval [CI], 5.1% to 7.2%; p < 0.001), the risk of mortality increased by 26% (odds ratio [OR] = 1.26, 95% CI = 0.98 to 1.61; p = 0.07), and the risks of periprosthetic joint infection and surgical site infection increased by 20% (OR = 1.20, 95% CI = 1.02 to 1.41; p = 0.03) and 14% (OR = 1.14, 95% CI = 1.00 to 1.31; p = 0.06), respectively. These associations were independent of the year of surgery, age, body mass index, Elixhauser comorbidity index, diagnosis of diabetes, in-hospital use of insulin or steroids, and mean glucose values during hospitalization.

CONCLUSIONS: Higher glucose variability in the postoperative period is associated with increased rates of surgical site and periprosthetic joint infections and may be a useful predictor of the risk of mortality following THA and TKA. Efforts should be made to control the glucose variability in the early postoperative period, and future studies should examine the role of continuous glucose monitoring in a subset of patients with high glucose fluctuations.

LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.