Joint failure in erosive osteoarthritis of the hands.

Erosive osteoarthritis (EOA), the type of hand osteoarthritis characterized by faster destructive changes, may be suspected clinically because of phlogistic presentation especially in DIP and in PIP joints. Scintiscan may be useful in early diagnosis, but the final diagnosis of EOA is always radiological, and depends upon the presence of central erosions. The inflammatory and crystal-induced origin of EOA is sometimes stressed in the literature, but despite the phlogistic course of the disease there is evidence against EOA being a primitive synovitis, the most cogent point being the cellular content of synovial fluid. The pathogenetic hypothesis that we propose is of a chondral primitive disorder, with synovitis causing further chondral erosion, subchondral bone damage, and finally joint instability or fibrous and bone ankylosis with severe impairment of joint function.