A volar approach to on-top plasty for correction of radial polydactyly: a case series of 21 patients

Abstract

Correction of unequal radial polydactyly in which neither thumb duplicates possess both well-developed proximal and distal components, remains challenging. Current techniques using on-top plasty techniques require circumferential incisions, often resulting in postoperative swelling and dorsal scars. We described our experience using a volar approach to achieve better aesthetic and functional results. Twenty-one patients underwent this surgery between 2008 and 2018, with a mean follow-up of 5.1 years. The mean flexion–extension arc for the metacarpophalangeal joint was 75° and that of the interphalangeal joint was 43°. Mean percentage of key, tripod and tip pinch strength were 77%, 79% and 77%, respectively, when compared with the contralateral side. The Vancouver Scar Scale showed an average score of 1.2. We conclude from our study that the volar approach to on-top plasty is a good technique for the correction of unequal radial polydactyly, with good functional and aesthetic results. Level of evidence: IV

Recent Advancements in the Diagnosis and Treatment of Congenital Hand Differences

“…In cases of unequal polydactyly, neither thumbs are considered dominant and require combining parts of each thumb, such as in the Bilhaut-Cloquet technique; however, this procedure is technically demanding, commonly producing nail bed deformities and an overall poor aesthetic outcome. 9,10 Mak et al 9 improved upon this historical technique with a neurovascular island flap that includes the pulp tissue and nail bed from the resected digit and a dorsal skin flap on the retained digit to improve size and symmetry (Figure 2). Fang et al 10 presented a modified on-top plasty to avoid dorsal scars by using palmar incisions and a pedicled transposition flap for first webspace correction found in unequal polydactyly.…”

“…9,10 Mak et al 9 improved upon this historical technique with a neurovascular island flap that includes the pulp tissue and nail bed from the resected digit and a dorsal skin flap on the retained digit to improve size and symmetry (Figure 2). Fang et al 10 presented a modified on-top plasty to avoid dorsal scars by using palmar incisions and a pedicled transposition flap for first webspace correction found in unequal polydactyly. Where resection and reconstruction of the preserved thumb is indicated, the fillet flap has been the conventional technique used to improve contour of the retained thumb.…”

Congenital Upper-Limb Differences

“…The thumb with the better-developed distal portion is isolated with its neurovascular pedicle and tendons and is transposed onto the proximal portion of the other thumb 44 . Studies of this technique have shown preserved functional range of motion and good quality-of-life scores 52,53 .…”

Update of surgical treatment of polydactyly

“…Shortcomings with this technique include issues around swelling, a short thumb, narrow first web and unpleasant dorsal scar formation [16,17]. Fang et al [18 ▪ ] in 2021 presents a volar approach to on-top plasty as an alternative to the traditional circumferential incision that avoids a dorsal scar, while increasing the length of the retained thumb and broadening the first web space. They also suggest meticulous reconstruction of the flexor and extensor tendon to strengthen the power for pinch and grasp and advocate early surgery wherever possible, to allow time for growth and secondary development.…”