We analysed retrospectively the risk factors
leading to femoral overgrowth after flexible intramedullary nailing
in 43 children (mean age 7.1 years (3.6 to 12.0)) with fractures
of the shaft of the femur. We reviewed their demographic data, mechanism
of injury, associated injuries, the type and location of the fractures,
the nail–canal diameter (NCD) ratios and femoral overgrowth at a
mean follow-up of 40.7 months (25.2 to 92.7). At that time, the
children were divided into two groups, those with femoral overgrowth
of <
1 cm (Group 1), and those with overgrowth of ≥ 1 cm (Group
2). The mean femoral overgrowth of all patients was 0.6 cm at final
follow-up. Overgrowth of ≥ 1 cm was noted in 11 children (25.6%).
The NCD ratio was significantly lower in Group 2 than in Group 1,
with an odds ratio of 30.0 (p = 0.003). We believe that a low NCD ratio is an indicator of an unstable
configuration with flexible intramedullary nailing, and have identified
an association between a low NCD ratio and femoral overgrowth resulting
in leg-length discrepancy after flexible intramedullary nailing
in paediatric femoral shaft fractures. Cite this article: