# Inflammation as a harbinger of death: a retrospective cohort study of preoperative biomarker risk stratification in orthopedic trauma

## TL;DR

This study shows that pre-surgery inflammation markers like MLR and CRP can predict survival chances in patients with broken femurs.

## Contribution

The study identifies monocyte-to-lymphocyte ratio (MLR) as a novel strong predictor of mortality in femur fracture surgery.

## Key findings

- Nonsurvivors had significantly higher MLR and CRP levels compared to survivors.
- MLR was the strongest predictor of both 30-day and 1-year mortality.
- CRP and MLR showed the highest predictive accuracy with AUC values of 0.811 and 0.765 for 30-day mortality.

## Abstract

This study aimed to evaluate the prognostic significance of preoperative inflammatory markers including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), C-reactive protein (CRP), and procalcitonin in predicting 30-day and 1-year mortality in patients undergoing femur fracture surgery.

This retrospective, multicenter cohort study included patients who underwent surgical treatment for femur fractures between January 2018 and December 2024. Patients were stratified into survivor and nonsurvivor groups based on 30-day and 1-year outcomes. Demographic characteristics, comorbidities, laboratory parameters, and inflammatory indices were recorded and analyzed. Linear and multivariate logistic regression analyses were performed to identify independent predictors of mortality. Receiver operating characteristic (ROC) curve analysis was used to assess the predictive performance of the inflammatory markers.

A total of 430 patients were included, 310 (72.1%) of whom survived while 120 (27.9%) died during the 1-year follow-up. The 30-day mortality rate was 15% (n = 65) and the 1-year mortality rate was 38% (n = 163). Nonsurvivors were significantly older (81.3 ± 9.6 vs. 75.2 ± 10.1 years, p < 0.001) and had higher rates of diabetes mellitus (45% vs. 30%, p = 0.003), hypertension (80% vs. 40%, p < 0.001), and chronic kidney disease (55% vs. 16%, p < 0.001). Laboratory analysis showed elevated white blood cell count, red cell distribution width, neutrophils, CRP, procalcitonin, NLR, PLR, and MLR, while albumin was lower in nonsurvivors (all p < 0.05). Multivariate analysis identified age, chronic kidney disease, low albumin, elevated creatinine, CRP, the MLR, and hospital stay as independent mortality predictors. The MLR showed the strongest association (OR = 4.12 for 30-day mortality; OR = 3.85 for 1-year). ROC analysis revealed CRP (AUC = 0.811 and 0.783) and the MLR (AUC = 0.765 and 0.751) as the most accurate predictors, followed by the NLR and hospital stay.

Preoperative inflammatory markers, particularly the MLR and CRP, were strongly associated with short- and long-term mortality in femur fracture surgery. Their integration into preoperative assessment may enhance risk stratification and guide clinical decision-making.