Treatment
Ulnar polydactyly
Ulnar polydactyly usually does not interfere with hand function, but for social reasons it can be treated operatively. Type A ulnar polydactyly
The treatment of Type A ulnar polydactyly is complex as its goal is to remove the accessory digit while maintaining a stable, functional small finger. When the duplicated proximal phalanx articulates with a common, broad metacarpal head, the ulnar collateral ligament must be considered. In those cases with a common articulation or with a sixth metacarpal the muscle executing the abduction of the little finger (abductor digiti minimi) must be preserved. In patients with a common metacarpal articulation an elliptical incision at the base of the post-axial digit is made. This incision may be extended proximally in order to adequately expose the abductor digiti minimi. The ulnar collateral ligament and the insertions of the abductor digiti minimi are then elevated with a periosteal sleeve. The duplicated extensor and flexor tendons to the ulnar digit are transected and after that the digit is amputated at its articulation with the metacarpal. If the articular surface is wide the metacarpal may be shaved. At last the collateral ligament and abductor digiti minimi are reinserted at the base of the preserved proximal phalanx and a wire is then placed across the reconstructed joint. In patients with a duplicated metacarpal, the accessory digit is amputated in a standard ray fashion with transfer of the abductor digiti minimi to the retained small finger. Type B ulnar polydactyly
In this situation there is an absence of osseous and ligamentous structures.
The neurovascular bundle which supplies the distal component is reserved and transferred proximally. Central polydactyly
Early osteotomy and ligament reconstructions should be done to prevent deformities, such as angular growth deformities.The surgical treatment of central polydactyly is highly variable. After the surgery the hand must be functional and stable, but also aesthetically pleasing. This requires intraoperative creativity and flexibility. The surgeon must also consider whether retention of a fully functional supranumerary digit is preferable to surgical intervention. In contrast, a functional, four-fingered hand achieved via ray amputation may be preferable to a five-fingered hand with a deformed or stiff reconstructed finger.Cases of polysyndactyly are approached through a standard opposing zig-zag incision. The incision is favored toward the accessory digit, preserving extra skin for subsequent closure. Depending on the level and extent of duplication, the flexor and extensor tendons may require centralization or rebalancing. Also, the collateral ligaments must be preserved or reconstructed. Wide articular surfaces should be narrowed and phalangeal wedge osteotomies may be required to provide an axial alignment. Attention must also be given to reconstruct the intermetacarpal ligament. Furthermore, one should take in mind the provision for adequate web-space soft tissue. Prognosis
Ulnar polydactyly
Type A ulnar polydactyly
There are no substantive outcome studies regarding the function of these hands following surgical intervention. This is mainly caused by the fact that there is a generally normal function of these patients’ hands following ablation with collateral ligament reconstruction.