The role of preoperative nutritional status in predicting surgical outcomes after total knee arthroplasty: A CONUT-based analysis

Abstract

Objectives: This study aims to investigate the association between the preoperative Controlling Nutritional Status (CONUT) score and two important postoperative outcomes, surgical site infection (SSI) and prolonged hospital stay, in patients aged 60 years and older undergoing total knee arthroplasty (TKA).

Patients and methods: Between February 2019 and December 2023, a total of 268 patients (54 males, 214 females; mean age: 68.2±5.9 years; range, 60 to 87 years) aged ≥60 years who underwent elective primary TKA were retrospectively analyzed. The Nutritional status was assessed using the CONUT score, and patients were categorized as at nutritional risk (CONUT ≥2) or normal (CONUT 0-1). Primary outcomes were postoperative infection and length of hospitalization. Multivariate logistic regression was used to adjust for confounding variables including age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, Visual Analog Scale (VAS), hemoglobin, C-reactive protein (CRP), and surgery duration.

Results: Of the patients, 27.2% (n=73) were at nutritional risk. These patients had significantly higher rates of postoperative infection (11% vs. 3.1%, p=0.010) and longer hospital stays (5.5±1.7 vs. 1.5±0.5 days, p<0.001). A higher CONUT score was independently associated with increased risk of infection (adjusted odds ratio [OR]=4.12; 95% confidence interval [CI]: 1.33-12.7; p=0.014) and prolonged hospitalization (adjusted OR=4.03; 95% CI: 3.75-4.30; p<0.001).

Conclusion: The CONUT score is a valuable tool for preoperative risk assessment in TKA. High CONUT scores are associated with an increased risk of postoperative infection and prolonged hospitalization. Routine nutritional assessment using the CONUT score prior to surgery in older adults may help improve surgical outcomes, reduce complications and lower healthcare costs.