Uncorrected Preoperative Malnutrition Is Associated with Worse Outcomes After Operative Fixation of Diaphyseal Tibial Fractures.

OBJECTIVES: To evaluate whether serum markers of malnutrition were associated with postoperative complications after tibial shaft fracture fixation, and whether postoperative correction mitigates this risk.

METHODS: Design: Retrospective cohort study.

SETTING: Multicenter (50 healthcare centers; North American national database).

PATIENT SELECTION CRITERIA: Adult patients ≥18 years of age undergoing fixation of tibial shaft fractures (OTA/AO 42) between January 1, 2013, and December 31, 2022, with a minimum of one year of follow-up were included. Patients with a history of malignancy or Gustilo-Anderson type III open fractures were excluded from the study.

OUTCOMES MEASURES AND COMPARISONS: The primary outcome was the occurrence of postoperative complications. Patients with serum markers for malnutrition were compared to matched controls. Malnourished patients with subsequently normalized serum markers were compared to previously matched healthy cohorts and cohorts with persistent malnutrition.

RESULTS: Following matching, a total of 10,722 patients were included for primary analysis: 5,361 malnourished patients with mean age 52 (range 18-90), 53.6% male and 5,361 control with mean age 53.2 (range 18-90) with 52.9% male. Preoperative malnutrition was associated with significantly higher rates of postoperative complications, including nonunion (RR=1.4), revision surgery (RR>1.4), infection (RR>2.0), failure of fixation (RR=1.3), thromboembolic events (RR>2.0), and sepsis (RR>2.0) (all p < 0.001). Among patients with preoperative malnutrition, those with uncorrected postoperative serum markers demonstrated higher risks of nonunion, revision, infection, and implant failure compared to those with serum markers that were corrected postoperatively (RR>2.0, all p<0.001). However, when compared to patients with normal preoperative nutrition values, individuals with postoperatively corrected malnutrition remained at increased risk for revision and infection (RR>1.4, all p=0.002) but not nonunion (6.5% vs. 5.6%, p>0.05) or failure of fixation (4.6% vs. 4.1%, p>0.05).

CONCLUSIONS: Malnutrition was associated with adverse surgical outcomes following tibial shaft fracture fixation, with significantly higher rates of nonunion, revision procedures, infection, wound complications, thromboembolic events, and medical morbidity compared with patients with normal preoperative nutrition. Postoperative correction of nutritional deficiencies reduced complication risk; however, residual risk remained elevated relative to patients with normal preoperative nutritional markers. These findings highlight malnutrition as a partially modifiable risk factor in tibial shaft fracture repair and support nutritional optimization as a part of postoperative management to improve patient outcomes.

LEVEL OF EVIDENCE: Level III.