Acute postoperative inflammatory polyarthritis associated with a lone IgM cardiolipin antibody.

While the most recognised complication after joint surgery is septic arthritis, other forms of joint pathology may occur. We present a case of postoperative polyarthritis with high inflammatory markers, which responded to a course of prednisolone. The occurrence of high IgM cardiolipin antibodies that normalised with treatment suggests that this condition is a form of transient autoimmunity.