In a study on 27 patients undergoing surgical excision for Type A ulnar polydactyly, only one complication was noted in the form of an infection
However, no investigators have objectively reviewed functional range of motion or articular stability. Type B ulnar polydactyly
In a study on 21 patients with Type B ulnar polydactyly treated with suture ligation it was found that the duplicated digit was typically amputated at an average of 10 days and no complications of infection or bleeding were reported. In a large study on 105 patients treated with suture ligation an overall complication rate of 23.5% was reported, citing a residual tender or unacceptable bump in 16%, infection in 6%, and bleeding in 1% of patients. In general, suture ligation is safe and effective when applied to appropriate cases of Type B polydactyly in which no substantial ligamentous or osseous structures are present within the pedicle. Parents should be educated as to the progression of necrosis, and that revision of residual tissue or scar may be necessary when the child is six months of age or older. Radial polydactyly
Bilhaut procedure
Advantages:
By combining two hypoplastic thumbs a sufficient thumb size is acquired. Furthermore, the IP and MCP joints are very stable as the collateral ligaments are not violated during reconstruction. Disadvantages:
Violation during reconstruction can lead to growth arrest or asymmetric growth. Nail deformity could also occur after reconstruction. Although the joints are stable, restriction of flexion may be possible. The average IP flexion in a reconstructed thumb is 55 degrees less than the contralateral thumb.
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.