Correlation between preoperative nutritional status and postoperative clinical outcomes in patients undergoing artificial hip and knee replacement

OBJECTIVE: To investigate the effect of prognostic nutritional index (PNI) on the clinical outcome of patients undergoing total hip/knee arthroplasty (THA/TKA), and to construct a nomogram prediction model. METHOD: A retrospective analysis was performed on 504 patients who underwent THA/TKA at The Third Affiliated Hospital of Chengdu Medical College, Pidu District People's Hospital from January 2020 to January 2025. Among them, 379 patients treated between January 2020 and January 2024 were used for model construction and internal validation, and 125 patients treated from February 2024 to January 2025 were used for external validation. Univariate and multivariate Logistic regression analyses were used to identify the independent risk factors for the clinical outcomes of patients, based on which a nomogram prediction model was established. RESULT: A total of 71 patients (14.09%) experienced adverse clinical outcomes. Multivariate analysis showed that T2DM and disease duration ≥ 10 years were independent risk factors for poor outcomes in THA/TKA patients (all P < 0.05). Higher WOMAC scores were associated with increased risk of adverse outcomes, while higher PNI levels were associated with reduced risk (both P < 0.05). Internal validation demonstrated good discrimination and calibration of the nomogram. In external validation, the sensitivity, specificity, and accuracy of the prediction model were 96.36% (106/110), 66.67% (10/15), and 92.80% (116/125), respectively. CONCLUSION: A low preoperative PNI level may increase the risk of poor outcomes in THA/TKA patients. The nomogram model incorporating PNI, T2DM, disease duration, and WOMAC score provides good reference for clinical assessment of postoperative risk.