[SURGICAL TREATMENT OF CONGENITAL TYPE V THUMB SYNDACTYLY]

To study the effectiveness of surgical treatment of congenital type V thumb syndactyly.

Between March 2010 and May 2015, 12 cases of congenital type V thumb syndactyly were treated. There were 7 males and 5 females, aged from 1 to 25 years (mean, 8 years). The right thumb was involved in 8 cases, and the left thumb in 4 cases. There were 2 cases of radial type, and 10 cases of ulnar type. The basement of polydactylism was far away from the carpometacarpal joint in 7 cases, and was close to the carpometacarpal joint in 5 cases (slight ulnar deviation in 1 case). X-ray films showed that the main first thumb metacarpal bone and trapezium fitted well, and 2 cases had the first metacarpal bone deformity. Preoperative individualized treatment plan was made, and polydactylism was excised by the "S" or "Z" incision and simultaneous reconstruction of thenar muscle insertions or adductor muscle insertions was performed; if necessary, wedge osteotomy was used for correction.

All incisions healed by first intention with no complication. All cases were followed up 6 to 24 months (mean, 12 months). The thumb appearance, flexion and extension, the function of opposition, abduction function were improved significantly in 11 cases with no scar contracture deformity, small first web space, and deviation deformity. One case had slightly narrow first web space. According to hand function criterion, the results were excellent in 10 cases, good in 1 case, poor in 1 case; excellent and good rate was 91.7%.

Based on the condition of the type V thumb syndactyly, the individualized treatment plan is made, which can better restore the shape and function of the thumb.