Critical analysis of tibial fracture healing following unreamed nailing.

Abstract

Unreamed nails have revolutionised the treatment of tibial shaft fractures. Many authors, however, have reported increasing bone healing complications with these implants. Unfortunately, few studies have addressed the factors affecting bone healing after unreamed tibial nailing. One-hundred and sixty tibial fractures in 158 patients (mean age 39.5 years) fixed using unreamed nails were reviewed. There were 78 AO type-A, 65 type-B and 17 type-C fractures (115 closed and 45 open fractures). Twelve patient, injury and surgery variables were analysed for their influence on fracture healing. Union occurred in all fractures after a mean time of 24.3 weeks. Additional surgery to achieve union, apart from dynamisation, was done in nine (6%) cases. The most important variables affecting healing were the mechanism of trauma (p=0.005), fracture site gap (p=0.01), degree of comminution (p=0.0003), associated soft tissue injuries (p=0.02) and the time to dynamisation (p=0.0001). High-energy trauma and fracture comminution have a negative impact on bone union and require close follow-up. It is essential to avoid distraction over three millimetres with unreamed nailing. Dynamisation is advised within ten weeks in axially stable fractures to encourage bone healing and avoid failure of the locking screws.