The treatment of metacarpal synostosis.

One hundred nine patients with metacarpal synostosis were examined to determine the best treatment for this condition. The fourth and fifth metacarpals are most frequently affected, and bilateral involvement occurs often. Many anomalies are associated with synostosis, as well as many syndromes such as Apert's syndrome, central polydactyly, syndactyly, and partial absence of the hand. An osteotomy to split and separate the synostosis, a bone graft to lengthen the fifth metacarpal, collateral ligament reconstruction, and tendon transposition of the extensor digiti minimi quinti all appear to be valuable for the treatment of this rare congenital anomaly.