Pathology of femoral heads in patients with rheumatoid disease.

In a study of 107 femoral heads removed surgically from 91 patients with generalized rheumatoid arthritis (RA), 96 showed rheumatoid stigmata; in 24 of these, fractures were a dominant feature. Of the 11 heads without rheumatoid stigmata, 5 had changes indistinguishable from osteoarthritis (OA), 5 had intracapital fractures and 1 had massive necrosis. The nature of eburnation was analyzed. Attention was drawn to fractures involving all the pillars supporting the subchondral plate and named "the dome shear fracture." The high incidence of fractures (29 of 107) was attributed to steroid therapy. The controls used were femoral heads from 400 patients with OA, 10 with ankylosing spondylitis and 10 treated with steroids for reasons other than RA. In most instances, a clear distinction could be made between RA and OA in the femoral head.