It can have idiopathic (unknown) causes, post-traumatic causes or be induced by the prolonged use of drugs (cortisone, chemotherapy). Regardless of the cause, the common factor concerns insufficient vascularization of the femoral head and consequent necrosis (usually in the region of greatest load) which weakens the structure leading to the collapse of the subchondral bone (which is located immediately under the cartilage) following the load, with the subsequent appearance of secondary arthrosis.

Groin pain worsening with weight bearing, radiating to the knee. Stiffness and limited hip movement.

Diagnosis is based on clinical examination, X-rays, and MRI, which can detect necrotic areas early. In early stages, conservative measures (off-loading, medication, physical therapy) are used. In advanced cases, surgical techniques or hip replacement may be necessary.

Collapse of the femoral head, secondary osteoarthritis, and functional disability.