Background: Thumb polydactyly is a common congenital abnormality of the hand. Surgical treatment includes reduction and reconstruction. A new type of thumb polydactyly and the achieved treatment are reported.
Methods: A 4-year-old boy with thumb polydactyly is reported. The duplicated two thumbs had one complete metacarpal and a separated triphalangeal phalanx. The ulna thumb was removed via periosteal incision, and a whole complex tissue sleeve was used to repair the ulna part of the joint capsule.
Results: The postoperative aesthetic and functional results were satisfactory.
Conclusions: A new type of thumb polydactyly that cannot be matched with the classification of either Wassel or Wood is described. The thumb polydactyly was treated by ablation via periosteal incision and ulna metacarpophalangeal joint capsule reconstruction. Three-dimensional computed tomography could be a good way to examine the area preoperatively.
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