Preoperative malnutrition is associated with increased early complications and higher two-year nonunion risk after Tibial shaft fracture fixation.

Abstract

Malnutrition is a potentially modifiable risk factor that may influence perioperative complications and fracture healing. This study evaluated the association between preoperative laboratory-defined malnutrition and short-term complications and 2-year outcomes following operative fixation of tibial shaft fractures. Using the TriNetX Research Network (112 healthcare organizations), adults (≥18 years) undergoing operative management for tibial shaft fracture were identified. Preoperative malnutrition was defined as albumin ≤3.5 g/dL and/or leukocytes ≤1.5 × 10³/µL within 1 year prior to the index event. Cohorts were propensity score matched 1:1 on demographics and comorbidities. Outcomes were assessed from day 1 post-index through 90 days (medical/surgical complications) and 730 days (healing-related and limb outcomes). Risk ratios (RR) and hazard ratios (HR) with 95% confidence intervals (CI) were reported. After matching, 44,780 patients were included in each cohort (89,560 total), with good balance across covariates (all SMDs <0.10). At 90 days, malnutrition was associated with higher risk of acute respiratory failure/mechanical ventilation (13.9% vs 3.4%; RR 4.10 [95% CI 3.88-4.33].; HR 4.32 [4.09-4.57].), sepsis (5.2% vs 1.2%; RR 4.35 [3.97-4.77].; HR 4.47 [4.07-4.91].), postoperative infection (5.7% vs 1.8%; RR 3.14 [2.90-3.39].; HR 3.23 [2.99-3.50].), acute kidney injury (8.6% vs 3.0%; RR 2.90 [2.73-3.08].; HR 2.99 [2.81-3.18].), and DVT/PE (6.5% vs 2.7%; RR 2.36 [2.21-2.52].; HR 2.42 [2.26-2.59].) (all p < 0.001). At 2 years, malnutrition was associated with increased nonunion (4.4% vs 1.6%; RR 2.69 [2.47-2.92].; HR 2.85 [2.62-3.10].), chronic osteomyelitis (12.5% vs 3.9%; RR 3.19 [3.02-3.36].; HR 3.50 [3.32-3.69].), hardware removal (10.1% vs 6.0%; RR 1.68 [1.61-1.76].; HR 1.83 [1.74-1.92].), and amputation (1.4% vs 0.4%; RR 3.47 [2.95-4.08].; HR 3.59 [3.05-4.23].) (all p < 0.001). Revision fixation did not differ (8.4% vs 8.1%; p = 0.096). Preoperative laboratory-defined malnutrition was independently associated with substantially higher 90-day morbidity and increased 2-year nonunion and limb-complication risk following operative tibial shaft fracture management. These findings support preoperative nutritional risk stratification and targeted optimization efforts in this population.