Remodelling of angular deformity after femoral shaft fractures in children.

We reviewed 28 children with unilateral middle-third fractures of the femoral shaft who had an angular deformity after union of 10 degrees to 26 degrees. At an average follow-up of 45 months (20 to 66), we measured remodelling of the proximal physis, the distal physis and the femoral shaft. The average correction was 85% of the initial deformity. We found that 74% of correction occurred at the physes and only 26% at the fracture site. Neither the direction nor the magnitude of the angulation much influenced the degree of remodelling. Younger children remodelled only a little better than older children. We conclude that in children under 13 years of age, malunion of as much as 25 degrees in any plane will remodel enough to give normal alignment of the joint surfaces.