Torsion of the leg determined by computed tomography.

Torsion of the leg was measured in 50 adults by computed tomography. The tangent to the dorsal aspect of the femoral condyles gave the proximal reference line. The distal reference line joined the centers of the medial and lateral malleoli. Tibial torsion was measured as the inclination between the dorsal tangent to the tibial condyles and the distal reference line, and torsion of the leg was measured as the inclination between the proximal and the distal reference lines. The anatomy of the dorsal aspects of the tibial condyles was more inconsistent than the anatomy of the dorsal aspects of the femoral condyles. In the females the external torsion of the leg was 38 +/- 9 degrees on the right side and 37 +/- 11 degrees on the left side. In the males the values were 41 +/- 6 degrees and 40 +/- 10 degrees, respectively.