Idiopathic avascular necrosis of the metacarpal head.

Avascular necrosis of the metacarpal head is a rare condition. Although the condition is associated with trauma, systemic lupus erythematosus, and steroid use, it can occur spontaneously without any obvious cause. Any metacarpal may be affected and the pathologic changes are similar to those described in other bones such as the femur. The diagnosis requires an index of suspicion in a young patient with spontaneous onset of symptoms localized to a metacarpophalangeal joint. Magnetic resonance imaging is a useful early diagnostic tool when the radiographic findings are nonspecific or absent. The natural history of the condition is not known. Although symptoms may resolve with nonoperative treatment, progressive collapse of the metacarpal head and subsequent degenerative arthritis is a possible long-term outcome. Curettage of the lesion and supplementary cancellous bone grafting has been reported to provide symptomatic relief in cases resistant to nonoperative treatment. A case is presented of idiopathic avascular necrosis of the head of the dominant ring finger metacarpal in a 27-year-old woman. The purpose of this report is to highlight the clinical presentation, radiographic features, pathologic findings, and outcome at 2 years after curettage and bone grafting.