Osteonecrosis is a complication of corticosteroid use, alcohol use, trauma, SLE, pancreatitis, gout, sickle cell disease, dysbaric syndromes (eg, “the bends”), and infiltrative diseases (eg, Gaucher disease). The most commonly affected sites are the proximal and distal femoral heads (eFigure 20–44), leading to hip or knee pain. Other commonly affected sites include the ankle, shoulder, and elbow. Osteonecrosis of the jaw is associated with the dose-related use of bisphosphonates, usually when high-dose intravenous bisphosphonate therapy is used for treating metastatic cancer or plasma cell myeloma rather than osteoporosis. Initially, radiographs are normal; MRI, CT scan, and bone scan are more sensitive techniques. Treatment involves avoidance of weight bearing on the affected joint for at least several weeks. The value of surgical core decompression is controversial. For osteonecrosis of the hip, a variety of procedures designed to preserve the femoral head have been developed for early disease, including vascularized and nonvascularized bone grafting procedures. These procedures are most effective in avoiding or forestalling the need for total hip arthroplasty in young patients who do not have advanced disease. Without intervention, the natural history of avascular necrosis is progression of the bony infarction to cortical collapse, resulting in significant joint dysfunction. Total hip replacement is the usual outcome for all patients who are candidates.
Avascular necrosis (AVN) of the ankle. Lateral (A) and internal oblique (mortise view) (B) radiographs of the ankle in a 25-year-old patient show ring-like sclerotic density in the distal tibia representing medullary infarct and subchondral sclerosis and lucency of the dome of the talus exhibiting subchondral AVN. Coronal T1-weighted spin-echo image of the ankle (C) and coronal fat-saturated T2-weighted image (D) showing a ring-like lesion representing medullary infarct in the distal tibial metaphysis and subchondral AVN of the dome of the talus exhibiting low signal in T1-weighted image and mixed "double-line" signal in the T2-weighted image. (Reproduced, with permission, from Tehranzadeh J. Basic Musculoskeletal Imaging, 2nd ed. McGraw-Hill, 2021.)