Multiple rib infarcts: a rare form of osteonecrosis in antiphospholipid syndrome.

O steonecrosis (ON) is a well known morbidity of several rheumatic diseases, usually affecting the hip, knee, shoulder, and ankle. The involvement of multiple or atypical sites by ON has been reported, especially in association with antiphospholipid antibodies (aPL). Rib infarction has been reported as a painful crisis of sickle cell disease, but has not been reported in rheumatic diseases. I describe here the first case of rib infarcts which developed in a patient with mixed connective tissue disease (MCTD) and secondary antiphospholipid syndrome (APS).