Rotational deformity and remodeling after fracture of the femur in children.

The remodeling potential of angular deformities in the coronal and sagittal planes in children is widely appreciated, and has been studied extensively. The short-term clinical consequences and remodeling potential of torsional deformity after fracture of the femur are less well understood. Computerized axial tomography (CT) was used to identify and follow children with torsional malunion after standard treatment (traction/spica cast) of a closed femur fracture. Seven fracture patients with torsional differences greater than 10 degrees were selected and observed. Computed axial tomography scans were performed at the time of spica cast removal and at the one-year follow-up examination. Four cases showed diminished femoral torsion (one case retroversion), and three cases showed increased femoral torsion. The deformity ranged from 13 degrees to 38 degrees. Follow-up CTs one year later showed no significant correction of deformity. Clinically, deformity of up to 25 degrees was well tolerated. The only symptomatic patient (38 degrees malunion) had a third CT done 28 months after injury, which showed no further correction of deformity. This study confirms the poor remodeling potential of significant posttraumatic torsional deformity of the femur in children.