Descriptive anatomy of the femoral portion of the iliopsoas muscle. Anatomical basis of anterior snapping of the hip.

Anterior hip snapping is a rare clinical observation. The physiopathological hypothesis currently held is a sudden slip of the iliopsoas tendon over the iliopectineal eminence. For symptomatic cases, a surgical technique is proposed. The aim of this work is to describe the anatomy of the femoral portion of the iliopsoas, which is the target of surgery. We have studied, through dissection of embalmed cadavers, the different components of the musculotendinous complex forming the femoral portion of the muscle and the gliding apparatus associated with it. The psoas major tendon exhibited a characteristic rotation. The iliacus tendon, more lateral, received the most medial iliacus muscular fibers, then fused with the main tendon. The most lateral fibers, starting in particular from the ventral portion of the iliac crest, ended up without any tendon on the anterior surface of the lesser trochanter and in the infratrochanteric region. The most inferior muscular fibers of the iliacus, starting from the arcuate line, joined the principal tendon of the psoas major passing around it by its ventromedial surface. An ilio-infratrochanteric muscular bundle was observed, in a deeper position, under the iliopsoas tendon; it arose from the interspinous incisure and on the anterior inferior iliac spine, ran along the anterolateral edge of the iliacus and inserted without any tendon onto the anterior surface of the lesser trochanter of the femur and in the infratrochanteric area. The iliopectineal bursa was studied on horizontal cross sections of a frozen pelvis and on 5 of the non-frozen preparations after dividing the iliopsoas tendon. The iliopectineal bursa had the shape of a 5 to 6-cm high and 3-cm wide cavity; in its upper part, it was divided into 2 compartments: a medial compartment for the main tendon and a lateral compartment for the accessory tendon.