Systemic lupus erythematosus and avascular bone necrosis.

Two cases of systemic lupus erythematosus (SLE) developing avascular bone necrosis are described. One case had eight separate areas involved (shouldres, hips, knees and both distal tibiae), which is the largest number in a single case of SLE yet reported. In both cases, at the onset of symptoms of necrosis in a new area, the antinuclear factor increased markedly compared to the preceding level. This indicates that the onset of the pathological process leading to necrosis is due to increased activity of the SLE rather than the steroid treatment.