Role of increased blood HbA1c as a positive predictor for infection in surgical management of closed proximal femur fractures among Type 2 Diabetes Mellitus (T2DM) patients

Background: Fracture-Related Infection (FRI) is a major postoperative complication of closed proximal femur fracture surgery. Glycated haemoglobin (HbA1c) among Type 2 Diabetes Mellitus (T2DM) has been found to be a good predictor of infection in elective orthopaedics, but its prognostic usefulness in acute fracture surgery remains uncertain.Materials and Methods: This retrospective analytical cross-sectional study comprised 91 T2DM patients who underwent surgery for closed proximal femur fractures at a medical college hospital between July 2022 and December 2024. Preoperative HbA1c levels measured within two weeks before surgery was linked to infection outcomes over a minimum five-month follow-up period. Clinical, analytical, microbiological, and radiographic criteria were employed to determine the infection. Data were evaluated using chi-square tests, t-tests, odds ratios, and multivariate logistic regression with ROC curve analysis to determine the optimal HbA1c threshold.Results: The average HbA1c was 8.13 ± 2.25%, with a mean age of 58.7 ± 8.6 years. Among 91 study patients, 12 had FRI, i.e., the infection rate was 13% (95% Confidence Interval; 7% to 21.9%). Staphylococcus species (75%) were the primary cause of FRI. Compared to the non-infected patients (7.8 ± 2.1%; t = 3.489, p-value 0.003; mean difference 2.4, 95% CI: 0.9-3.8), the patients with infection had a significantly higher mean HbA1c (10.2 ± 2.2%). Infection rates were 4.5% (1) for patients with HbA1c 7.5% (p-value 0.03). According to ROC analysis, an optimum HbA1c cutoff of 9.5% predicted infection with 75% sensitivity and 78.5% specificity, yielding an AUC of 0.764 (95% confidence interval: 0.613-0.915, p-value of 0.003). Age, gender, fracture type, comorbidities, and body mass index had no significant correlation with infection.Conclusion: In surgically treated closed proximal femur fractures among T2DM patients, elevated perioperative HbA1c is an independent predictor of postoperative FRI. For infection risk stratification in trauma settings, an HbA1c threshold of ≥9.5% provides moderate diagnostic accuracy. Optimising glycaemic levels prior to surgery could lower the risk of infection among T2DM patients.