Creation of an opposable small finger by muscle transfer.

We present a case of a child born with metacarpal synostosis of the index, long, and ring fingers associated with a simple syndactyly of the small finger and an absent thumb. At age 7 months, a syndactyly release with skin grafting to the small finger was accomplished so that it became the new thumb. At age 4 years, one of the muscles on the radical border of the hand was transferred to the small finger to act as an opposition transfer. At follow-up, the transfer contracted well and the functional capability of the hand was improved. This operation will not often be used but should be considered for the occasional patient with congenital anomalies.