Operative techniques for correction of syndactyly need to address many potential problems:
- options for recreation of web space include:
- dorsal rectangular flap of thinner, more mobile skin tranposed into palmar defect(1):
- commonly used
- trapezoidal in shape
- designed by measuring the length of neighbouring commissures and adding a few millimetres to this length to allow for minor adjustments
- centered on the middle of the interdigital space of the syndactylised digits
- typically 8-9 mm in width at base and narrower at tip
- modification of this design with:
- dorsal triangular skin flaps to aid in resufacing of dorsal sides of digits
- making the tip of the rectangular flap oblique, diamond shaped or 'M'-shaped to fit into a 'Y'-shaped defect volarly
- rectangular flaps from the volar side
- transposition of opposing palmar and dorsal inverted-V triangular skin flaps
- island flap method eg using a V-Y advancement of an island of dorsal skin into the commissure
- dorsal four flap z-plasty
- jumping man flap
- historically as uniformly prone to poor results, simple division of skin or free skin grafting alone
- separation of digits:
- classically, achieved by interdigitating triangular skin flaps from the volar and dorsal surfaces of the digit(2):
- typically, 60 degree angles at the tips of flaps with none crossing perpendicular to flexion creases
- obliquity of scars reduces the risk of flexion contracture
- usually not enough skin to resurface the sides of both digits and small full thickness skin grafts are placed into the gaps; grafts are usually harvested from the groin and inset under minimal tension; other options for donor sites include the medial malleolar area of the foot
- other described options include:
- simple longitudinal separation; prone to poor results but may be useful in the unusual situation of Apert's Syndrome where symphalangism prevents flexion contractures
- tissue expansion dorsally to obviate the need for skin grafting
- bone distraction away from the meridian of the web to create more skin prior to division
- pedicled distant flaps for skin cover eg groin flap
- recreation of nail fold: Buck-Gramcko technique with a flap of triangular pulp folded back onto the ipsilateral margin of the nail
Ref: (1) Bauer TB, Tondra JM, Trusler HM (1956). Plast Reconstr Surg; 17: 385-392. (2) Cronin TD (1956). Plast Reconst Surg; 18: 460-468.