Outcome of Perthes' disease in unselected patients after femoral varus osteotomy and splintage.

We evaluated 56 hips (48 patients) with Perthes' disease to compare the radiographic results of two unselected groups: one treated with femoral varus osteotomy (22 hips) and another with Thomas splint (34 hips). The patients with less than 50% femoral head involvement (Salter Group A hips) seemed to have no advantage from the operation. The angle of the femoral neck was 10 degrees less in the operative group than in the nonoperative group. In hips with more than 50% head involvement (Salter Group B), the operative method resulted in slightly better coverage and sphericity of the femoral head than the conservative method. On average, the acetabular direction was similar in both groups. The authors conclude that femoral varus osteotomy may lead to residual coxa vara and does not necessarily improve the radiographic results in limited epiphyseal involvement. Neither does the operation have an effect on the acetabular direction in severe Perthes' disease.