Few published series demonstrate the complications of flexible intramedullary nailing of unstable tibial diaphyseal fractures in children. A retrospective review of nineteen patients was performed, as well as a biomechanical analysis. Two common implant configurations were compared, double or divergent C and medial C and S. Five patients (26%) had complications. Two angular deformities (> 10°) occurred with the medial C and S. The C and S demonstrated lower range of motion than the double c. Despite it’s inferiority in biomechanical testing, the double c construct was associated with fewer complications and is the authors’ preferred technique.

To summarize the complications seen with intramedullary flexible nailing of tibial diaphyseal fractures and to examine the clinical outcomes and biomechanical properties between two different fixation constructs (double C vs. C and S constructs).

A retrospective review of nineteen patients was performed, as well as a biomechanical analysis of stability in torsion and compression when using two types of implant configurations in a pediatric sized synthetic tibia model. Outcome measures included union rates, residual deformity, and complications. Five patients (26%) had complications. Union occurred in all cases. None required repeat operation. Two (11%) angular deformities (> 10°) occurred with the medial C and S construct, versus none with the double C. The C and S configuration demonstrated significantly lower range of motion (32 + 4 degrees) compared to the double c configuration (71 + 20 degrees) (p< 0.03). There was no statistical difference in failure load at 5mm of gap closure between the C and S configuration (105 + 62N) and the double c configuration (40 + 42N) (p=0.2).

The C and S construct was superior in biomechanical testing, however the double c construct had no angular deformities greater than ten degrees in the clinical series. Flexible intramedullary nail fixation is a straightforward technique that reliably produces good results. Despite it’s inferiority in biomechanical testing of a synthetic tibia model, the double c construct was associated with fewer complications and is the authors’ preferred technique.