A review of supernumerary thumb and its surgical management.
Type II polydactyly is relatively easy to treat by simple ablation. Central wedge resection is an alternative treatment, providing sufficient bone and soft tissue are excised. Duplication at the MP joint may be difficult to treat because of the frequently associated problems of joint deviation and limited motion, which may produce unacceptable results. MP joint deviation in the ulnar direction of less than 30 degrees does not require treatment. Treatment may be necessary for ulnar deviation greater than 50 degrees. Metacarpal osteotomy, arthrodesis, and central wedge resection are methods of treatment. Collateral ligament reconstruction and tendon transfer were unsuccessful in one patient. IP joint deviation of greater than 15 degrees may need treatment. If there is less than 10 degrees of motion associated with it, arthrodesis is indicated when the joint is skeletally mature. When opposition is impaired thenar muscle tendon transfer is an effective treatment.