Unilateral osteonecrosis in a patient with bilateral os centrale carpi.

Accessory carpal bones, although uncommon, are usually of no clinical significance. This report describes a patient who had bilateral presence of the accessory bone called the os centrale carpi. The patient was seen with disabling pain in the dominant right wrist and both radiologic and pathologic findings showed osteonecrosis and secondary degenerative arthritis. His left wrist was asymptomatic and the accessory ossicle was normal in appearance. We have not been able to discover any cases in the literature describing the development of unilateral osteonecrosis in a patient with bilateral os centrale capri.