Anteversion of the acetabulum and femoral neck in normals and in patients with osteoarthritis of the hip.

Anteversion of the acetabulum and of the femoral neck was determined by use of computed tomography in 47 adults with normal hips and in 39 patients with osteoarthritis. The normal anteversion of the acetabulum was found to be 17 +/- 6 degrees (mean +/- standard deviation) and of the femoral neck 13 +/- 7 degrees. In the patients with osteoarthritis the femoral anteversion was on the average 6 degrees larger than in the normals, whereas no difference was revealed in the figures of acetabular anteversion. The relationship between the degree of femoral and of acetabular anteversion was calculated. No correlation was found, neither in the normals, nor in the patients. Consequently, the relationship between the anteversion of the femoral neck and of the acetabulum was poor in the patients as compared to the controls, and it is concluded that this is a contributing factor to osteoarthritis due to poor adaptation of the femoral head to the acetabulum.