The femoral artery and flexion of the hip joint.

The behavior of the femoral a. when the hip joint passes from the position of extension to the position of flexion at 90 degrees was studied in 13 cadavers, using several methods: anatomic sections, arteriographies or vascular casts. The modifications of the direction and shape of the femoral a. were assessed in the frontal and sagittal planes. They result from a movement combining flexion and torsion of the femoral a. on its axis at 2 different points in its course. The change of direction of the artery in the sagittal plane is the most obvious modification. It corresponds to the displacement and to the inversion of an angle of 45 degrees on the course of the artery. This angle is situated below the level of the inguinal ligament when the hip joint is in extension and above the sartorius m. when it is flexed to 90 degrees. If these modifications are produced in a similar manner in the living subject, they would seem to correspond to the best possible functional adaptation of the femoral a. They may be involved in the genesis of prosthetic aneurysms.