Risk Factors and Healing Outcomes in Tibial Shaft Fractures

Background: Tibial shaft fractures represent the most common long bone fractures encountered in orthopedic practice, with healing outcomes varying considerably among patients. Delayed union and nonunion remain significant complications, leading to prolonged disability, additional surgical interventions, and increased healthcare expenditure. Identification of patient-specific and injury-related risk factors influencing healing trajectories is essential for optimizing treatment strategies and prognostic counseling. Methods: This retrospective cohort study analyzed 438 consecutive patients with tibial shaft fractures treated at a university-affiliated trauma center between January 2019 and June 2023. Demographic, injury-related, treatment-related, and comorbidity variables were collected from medical records. Healing outcomes were categorized as normal union (radiographic consolidation within 6 months), delayed union (6–9 months), and nonunion (absence of healing at 9 months). Univariate and multivariable logistic regression analyses were performed to identify independent predictors of impaired healing. Results: Normal union was achieved in 348 patients (79.5%), delayed union in 58 (13.2%), and nonunion in 32 (7.3%). The mean time to radiographic union was 18.4 ± 6.8 weeks. Independent risk factors for impaired healing (delayed union or nonunion combined) included open fracture classification (OR: 3.24; 95% CI: 1.865.64; p < 0.001), smoking status (OR: 2.68; 95% CI: 1.58–4.55; p < 0.001), fracture gap >3 mm after fixation (OR: 2.91; 95% CI: 1.54–5.49; p = 0.001), diabetes mellitus (OR: 2.12; 95% CI: 1.18–3.81; p = 0.012), and high-energy mechanism of injury (OR: 1.94; 95% CI: 1.14–3.30; p = 0.014). Conclusion: Impaired healing following tibial shaft fractures occurs in approximately one-fifth of patients. Open fracture severity, active smoking, inadequate fracture reduction, diabetes mellitus, and high-energy injury mechanisms independently predict adverse healing outcomes. Addressing modifiable risk factors through smoking cessation programs and meticulous surgical reduction may improve union rates. Keywords: Tibial Shaft Fracture; Delayed Union; Nonunion; Risk Factors; Fracture Healing; Smoking; Open Fracture; Intramedullary Nailing.