Secondary fractures associated with external fixation in pediatric femur fractures

Sixty-six femur fractures sustained by children ages 4-14 years and treated with external fixation were reviewed retrospectively to assess factors inf luencing the incidence of refracture. The total rate of secondary fracture was 12% (eight patients) including five recurrent fractures at the original fracture site arid three fractures through the pin sites. After removal of the external fixator, five patients refractured at the original fracture s ite and one patient fractured through a pin tract. Two patients fractured a t pin sites while the fixator was still in place. Multivariate linear-repre ssion analysis showed no correlation between the incidence of refracture an d fracture pattern, percentage of bone fragment contact after fixator appli cation, type of external fixator, or dynamization. A statistically signific ant association (p < 0.05) was Found between the number of cortices demonst rating bridging callus [on both anteroposterior (AP) and lateral views] at the time of fixator removal and the rate of refracture. Fractures showing f ewer than three cortices of bridging callus had a three (33%) in nine rate of refracture, whereas fractures with three or four cortices of bridging ca llus had a two (4%) of 57 rate of refracture.