Glycemic thresholds for surgical site infection risk in orthopaedic trauma: Insights from patients with diabetes mellitus and stress-induced hyperglycemia

HbA1c and blood glucose measurements are used to assess diabetes mellitus (DM) and stress-induced hyperglycemia (SIH) in risk stratification of surgical site infection (SSI). However, heterogeneity among various studies reveal that there is no uniform standardized threshold for HbA1c and blood glucose to predict risk and management of SSI in postoperative orthopaedic trauma procedures. This narrative review will (1) identify studies that found an increased SSI risk in patients with diabetes (PWD) using a spectrum of different HbA1c and blood glucose thresholds; and (2) determine whether SIH in patients without diabetes (PWOD) displays comparable trends. Between January 2013 and August 2024, a structured search of PubMed, Embase, and the Cochrane Library was performed to identify studies evaluating the association between glycemic markers and SSI risk in orthopaedic trauma PWD and PWOD. Studies reported HbA1c and/or blood glucose thresholds in the context of SSI occurrence following orthopaedic trauma procedures. HbA1c thresholds for elevated SSI risk in PWD ranged from ≥7.0% to 8.0%, while fasting and random blood glucose cutoffs ranging from ≥130 to 140 mg/dL and 188 to 200 mg/dl. In PWOD, SIH was associated with infection with fasting blood glucose as low as ∼125 mg/dL, with infection rates rising at fasting blood glucose levels >200 mg/dL. The wide variability in reported HbA1c and glucose cutoffs underscores the need for standardized thresholds to aid clinicians with perioperative glucose management strategies to optimize surgical outcomes regardless of diabetic status.