Relationship between controlling nutritional status (CONUT) and surgical site infection (SSI) following elective foot and ankle surgery

This study aims to examine whether the preoperative controlling nutritional status (CONUT) score was associated with SSI following elective foot and ankle surgeries. This study retrospectively reviewed adult undergoing elective foot and ankle surgeries in a tertiary university-affiliated hospital between January 2019 and May 2023, and identified who subsequently developed an SSI within 12 months postoperative. CONUT score was calculated from serum albumin, lymphocyte count, and toral cholesterol concentration, and its optimal cut-off value for differentiating SSI risk was determined by the receiver operating characteristic curve. Three independent hierarchical multivariable logistic regression models, adjusting demographics, confounders or covariates were constructed to examine the association. Among 1,424 surgical procedures performed in 1,221 patients, 36 (2.5%) SSIs were identified, with 21 (1.5%) superficial cases and 15 (1.1%) deep cases, respectively. The optimal cut-off for CONUT was 3, and significant differences were observed between patients with CONUT ≥ 3 and those < 3, in terms of age, BMI, anesthesia, procedure, bleeding, preoperative prophylactic antibiotics, and admission sodium. Multivariate analyses showed consistent significant results (OR 4.66 and 95% CI 2.32 to 9.37 after adjustment for demographics; OR 4.72 and 95% CI 2.22 to 10.02 for adjustment for confounders, and OR 3.80 and 95% CI 1.68 to 8.59 for further covariates). This finding may aid clinicians in conducting individualized assessments of SSI and developing a more tailored SSI risk profile for patients undergoing such procedures.