Osteonecrosis (Avascular Necrosis of Bone)

Key Features

• A complication of

  • Corticosteroid use

  • Trauma

  • Systemic lupus erythematosus (SLE)

  • Pancreatitis

  • Alcoholism

  • Gout

  • Sickle cell disease

  • Dysbaric syndromes

  • Knee menisectomy

  • Infiltrative diseases (eg, Gaucher disease)

• The natural history is usually progression of the bony infarction to cortical collapse, resulting in significant joint dysfunction

Clinical Findings

• Most commonly affected sites are the proximal and distal femoral heads, leading to hip or knee pain

• Other commonly affected sites include the ankle, shoulder, and elbow

• Osteonecrosis of the jaw is associated with use of bisphosphonate therapy, usually when the bisphosphonate is used to treat metastatic cancer or plasma cell myeloma rather than osteoporosis

• Hip or knee pain

  • Many patients with hip disease first present with pain referred to the knee; however, internal rotation of the hip—not movement of the knee—is painful

Diagnosis

• Initially, radiographs are often normal

• MRI, CT scan, and bone scan are more sensitive techniques

• Differential diagnosis

  • Osteoarthritis or rheumatoid arthritis

  • Fracture

  • Joint pain resulting from other cause

Treatment

• Avoidance of weight bearing on the affected joint for at least several weeks

• Surgical core decompression is controversial

• Total hip replacement is the usual outcome for all patients who are suitable candidates