The effect of intertrochanteric osteotomy on the venous drainage of the femoral neck in Perthes' disease.

Intraosseous femoral neck venography was performed both pre- and postoperatively on 30 patients with Perthes' disease. At the time of the operation (osteotomy) and the preoperative venographies, the disease was in the initial stage in 16 patients, in the fragmentation stage in eight patients and in the restitution stage in six patients. As shown previously the venous drainage of the femoral neck preoperatively, in the initial and fragmentation stages of the disease, was different from the venous pattern of the healthy (control) hips in every case, indicating an obstruction of the venous flow. 4-15 months after the osteotomies this venous obstruction had disappeared completely or almost completely in most cases. This normalization happened sooner than expected on the basis of our findings with conservatively-treated patients.