[Periarticular diseases of the hip in young adults].

Multiple periarticular structures are present around the hip joint: tendons, bursae, muscles and entheses, fascias, nerves and vessels. Periarticular diseases of the hip in young adults include, in decreasing order of functional impairment: posttraumatic lesions of muscles and tendons that should not be overlooked because of the risk of functional sequelae, enthesopathy detected on plain films and ultrasound, snapping hip syndrome frequent in athletes and tunnel syndromes (such as compression of the lateral femoral cutaneous nerve where ultrasound is valuable). The main pitfalls to avoid are the stress fracture, trauma to a pelvic muscle and calcium deposition.