Long Bone Union Accurately Predicted by Cortical Bridging within 4 Months

Area of Science:

• Orthopaedic surgery
• Traumatology
• Radiographic assessment

Background:

• Previous studies indicated bridging callus within 4 months predicts tibial shaft fracture healing.
• A consensus on early prognostication for long bone nonunion is lacking.
• This study prospectively evaluates early callus formation for predicting union in tibial and femoral shaft fractures.

Purpose of the Study:

• To assess the accuracy and reliability of bridging callus presence within 4 months for predicting union in tibial and femoral shaft fractures.
• To compare the predictive value of any bridging callus versus bicortical or tricortical bridging.
• To establish a simple and reliable method for early fracture healing prognostication.

Main Methods:

• Prospective cohort study of 126 tibial and femoral shaft fractures treated with intramedullary nailing.
• Radiographs taken 3-4 months postoperatively were assessed by three orthopaedic traumatologists.
• Chi-square analysis and kappa statistics were used to evaluate accuracy and interobserver reliability for predicting union/nonunion based on callus formation.

Main Results:

• The overall nonunion rate was 4%.
• Any bridging callus within 4 months accurately predicted union (121/122) and absence predicted nonunion (4/4).
• Bicortical and tricortical bridging showed higher accuracy when present but were less reliable and risked overestimating nonunion when absent.

Conclusions:

• The presence of any bridging callus within 4 months is a simple, accurate, and reliable predictor of final healing outcomes for tibial and femoral shaft fractures.
• Standard radiographs are sufficient for this assessment.
• Relying on bridging of additional cortices leads to overestimation of nonunion rates and reduced reliability.