Controlling Nutritional Status (CONUT) score is associated with increased rates of mortality and postoperative complications following hip fracture surgery: a propensity-matched analysis.

Abstract

Controlling Nutritional Status (CONUT) score has previously been linked to increased mortality following hip fracture. The objective of this study was to evaluate the association between preoperative CONUT score and other postoperative complication rates in patients who underwent surgical hip fracture fixation. This study utilized the TriNetX Research Network to identify patients aged ≥ 65 with a previous history of hip fracture surgery between May 1, 2015, and May 1, 2025. Patients with a documented history of primary malignant neoplasm of the lower limb or secondary bony metastasis were excluded. Next, patients were separated according to calculated CONUT score using laboratory data available within six months of the index procedure. Patients with a CONUT score between 0 and 4 were considered no to low risk whereas those with a value between 5 and 12 represented the moderate to severe risk cohort. Propensity score matching was performed 1:1 based upon demographic characteristics and medical comorbidities. Outcomes were assessed within 30 days of surgery utilizing risk ratios (RR) and 95% confidence intervals (CI). A total of 1,209 matched pairs were included in the analysis. After matching, there were no differences between the two groups with respect to any of the covariates included in the propensity score. CONUT score ≥ 5 was associated with elevated risk of all-cause mortality within 30 days (10.0% versus 3.8% in low to no risk group, <i>p</i> < 0.001) alongside increased incidence of pneumonia, sepsis, acute respiratory failure, acute renal failure, postoperative infection, and all-cause hospital readmission. CONUT score ≥ 5 is associated with increased incidence of mortality and significant postoperative complications within the 30 days following hip fracture fixation. Thus, it appears that CONUT score may be appropriate for the identification of high-risk hip fracture patients so appropriate prophylactic measures can be taken. The online version contains supplementary material available at 10.1007/s00590-026-04760-8.