Anatomic factors in the femoral implantation of the Ilizarov external fixator.

Ilizarov's method of external fixation with compression or distraction for lesions of the limbs demonstrates new possibilities in osteogenesis. Its performance with double horizontal pinning on several external rings calls for precautions to avoid lesions of the vessels, nerves and joints. This study, based on anatomic sections radiographed after opacification of the arterial system, makes it possible to propose rules for insertion of the pins. Insertion of the anteromedial pins of the thigh should be made 2 cm in front of the line of projection of the femoral artery, between the middle of the inguinal ligament and the posterior margin of the medial condyle. Insertion of the posterolateral thigh pins should be made 2 cm lateral to the line of projection of the sciatic nerve, between the center of the ischiotrochanteric interval, the apex of the popliteal fossa and the posterior aspect of the head of the fibula.