Avulsion of the quadriceps tendons in a patient with an unusual deforming arthritis and varied skin lesions.

Spontaneous avulsion of both quadriceps tendons occurred in a young woman who had been treated with corticosteroids for progressive severely deforming seronegative arthritis and recurring skin lesions clinically and histologically suggestive of cutaneous vasculitis and pyoderma gangrenosum. We postulate that recurrent minor trauma to tendons previously damaged by vasculitis and inhibition of tendon repair by oral corticosteroids were predisposing factors to the bilateral tendon avulsions.