Prevention of malrotation deformity in femoral shaft fracture.

OBJECTIVE: To confirm the need to check anteversion (AV) of the intact femur to prevent malrotation deformity following intramedullary nailing in femoral shaft fracture.
DESIGN: Prospective.
RESULTS: Four patients out of forty-two (forty-three nailings) developed malrotation deformity of more than 15 degrees after femoral nailing. In the second part of the study, distal fragments of the fractured femurs were rotated 13.8 degrees on average to match with the rotational alignment of the intact femur. The malrotation deformity was controlled to less than 5 degrees in all cases. Closed reduction along the longitudinal axis of the femur was performed and was acceptable in forty-two cases (thirty-four cases in Part 1 of the study and eight cases in Part 2) prior to nailing. The coefficient of correlation between preoperative and postoperative AVs was 0.73 in these cases.
CONCLUSION: Because true neutral rotation of the distal fragment alone is not accurate in preventing malrotation deformity of the femur following intramedullary nailing, we recommend measuring AV in both intact and fractured femurs and correcting rotational malalignment if it exists at the time of femoral nailing. Rotational alignment did not change significantly unless we failed to externally reduce the fracture due to a flexion deformity of the proximal fragment.