Avascular necrosis of bone in severe acute respiratory syndrome

AIM: To report the incidence of avascular osteonecrosis (AVN) in severe acute respiratory syndrome (SARS) patients. MATERIALS AND METHODS: Sixty-seven SARS patients who had large joint pain between March 2003 and May 2003 underwent both plain radiographs and magnetic resonance imaging (MRI) examination on the same day. All patients received steroids and ribavirin treatment. All plain radiographs and MR images were analysed by two experienced musculoskeletal radiologists. Any abnormalities, location, extent, morphology, the number, size and signal intensity of lesions were evaluated. RESULTS: Twenty-eight patients were identified with AVN, The mean time to diagnosis of AVN was 119 days after the onset of SARS, or 116 days after steroid use. Three patients had early bilateral AVN of the femoral head, four patients of one femoral head, five patients of the bilateral hips and knees, four patients of the ipsilateral hip and knees, 10 patients of the knee(s), one patient of the right proximal fibula, and one patient of the knees and talus. Results of hip, knee and ankle plain radiographs were negative. CONCLUSION: AVN can occur in the patients with SARS. AVN had a strong association with steroid use. More studies are required to confirm whether the virus itself can also lead to AVN.