Preoperative malnutrition is associated with increased infectious, vascular, and wound complications after distal femur fracture fixation.

OBJECTIVES

Distal femur fractures (DFF) are serious injuries that frequently affect older, medically complex patients. Malnutrition worsens outcomes in elective orthopaedic surgery, but its impact in urgent DFF fixation, where preoperative optimization time is limited, remains unclear. This study evaluated whether preoperative malnutrition predicts 90-day morbidity after DFF fixation and whether implant choice modifies risk among malnourished patients.

METHODS

Adults undergoing operative DFF fixation from 2005 to 2025 were identified in the TriNetX US Collaborative Network. Malnutrition was defined as serum albumin ≤3.5 g/dL or leukocyte count ≤1.5 × 10³/µL within one year before surgery. After 1:1 propensity matching for demographics and comorbidities, outcomes were compared between 13,924 malnourished and 13,924 non-malnourished patients. A secondary matched analysis compared plate versus intramedullary nail fixation in malnourished patients (n = 662). Ninety-day postoperative complications, readmission, and opioid-related outcomes were assessed.

RESULTS

Malnourished patients had significantly higher rates of nearly all 90-day complications, including sepsis (risk ratio [RR] 3.55), surgical site infection (RR 3.05), wound disruption (RR 3.38), pulmonary embolism (RR 2.09), pneumonia (RR 2.45), renal failure (RR 2.53), anemia (RR 1.97), and transfusion (RR 2.52) (all p < 0.001). Ninety-day readmission and opioid-related outcomes were also substantially increased. Among malnourished patients, overall complication rates were similar between plate and nail fixation, with the exception of lower pneumonia rates in the plate cohort (p = 0.045).

CONCLUSIONS

Preoperative malnutrition is a strong, independent predictor of postoperative morbidity after DFF fixation, and complication risk remains high regardless of implant choice. Routine nutritional screening with simple laboratory markers and targeted perioperative optimization should be integrated into trauma workflows to improve outcomes in this vulnerable population.