Skin Grafting in the Hand

A skin graft carries no blood supply of its own, so it survives only if the recipient bed can nourish and revascularise it. Take occurs in three phases: plasmatic imbibition in the first ~48 hours, when the graft absorbs nutrients by diffusion from the bed; inosculation at ~48-72 hours, when graft and bed capillaries align and connect; and revascularisation from about day 4-7, when new vessels grow into the graft. A split-thickness graft (epidermis + part of dermis) is thinner, so it imbibes and revascularises more readily and takes more reliably, but it contracts more and is less durable; a full-thickness graft (epidermis + full dermis) needs a better bed but contracts less and is more durable and sensate.

• Palm and fingertips: use a FTSG, ideally from GLABROUS (non-hairy) skin - the hypothenar eminence or the instep - to match the thick, hairless, durable palmar skin and provide better sensation; an FTSG/glabrous graft is reliable for fingertip and donor-site defects.
• Across flexion creases: prefer FTSG (or a flap) because STSG secondary contraction can cause a flexion contracture - a major functional problem in the hand.
• Dorsum and large defects: STSG (e.g. from the thigh) gives reliable cover; meshing expands area and lets exudate escape but worsens cosmesis/contraction.
• Donor sites for FTSG: wrist/hypothenar crease, antecubital fossa, medial arm, groin (hairless areas preferred for the hand).
• Exposed bone/tendon/cartilage without periosteum/paratenon/perichondrium, or infected/irradiated beds: a graft will fail - choose a flap (local, regional or free).

The commonest reasons a graft fails are a HAEMATOMA or SEROMA lifting it off the bed, INFECTION, and SHEAR/movement. Prevent these with meticulous haemostasis, a bolster (tie-over) dressing or negative-pressure dressing to maintain contact, and immobilisation/splinting of the hand for the first ~5 days; treat any infection and avoid grafting onto a clearly contaminated wound (delayed grafting after the bed is clean - 'delayed primary' grafting - is an option). Counsel about graft hyperpigmentation and reduced bulk.

• Primary contraction. The immediate elastic recoil a graft shows the moment it is harvested, due to the elastin in the dermis - so it is greater in a full-thickness graft (more dermis/elastin) than a split graft. Practically, harvest an FTSG slightly larger than the defect to allow for it.
• Secondary contraction. The contraction of the grafted wound as it heals, driven by myofibroblasts in the recipient bed - this is greater with a split graft (little dermis to restrain it) and less with a full-thickness graft, because the more dermis a graft carries, the more it inhibits the myofibroblast-driven contraction. This is the functionally important one in the hand.
• Why it dictates hand choices. Across a flexion crease or on the palm/fingertip, the marked secondary contraction of an STSG would pull the digit into a flexion contracture - so a full-thickness (ideally glabrous) graft is preferred there; on the dorsum or large wounds, where contracture matters less, the more-reliable STSG is acceptable.

• STSG harvest. Taken at a set, calibrated thickness with a powered dermatome or a Watson/Humby knife (the guard sets the depth), usually from the thigh; the donor heals by re-epithelialisation from retained dermal adnexa under a semi-occlusive/alginate dressing.
• Meshing. The STSG can be passed through a mesher (ratios such as one-and-a-half to one) to expand its area and let exudate/haematoma escape - at the cost of a cobblestoned appearance and more contraction; small hand grafts are often fenestrated/pie-crusted by hand instead.
• FTSG harvest. Cut to a template of the defect, taken full-thickness, then defatted (all subcutaneous fat trimmed off the dermis so the bed can nourish it), and the donor site closed primarily - which limits the size available.
• Inset and securing. The graft is trimmed to fit, sutured/secured without tension, fenestrated to drain, and held in firm contact by a tie-over (bolster) dressing or negative-pressure dressing; the hand is splinted/immobilised and the graft typically first inspected at about day five.

The reliability of FTSG for fingertip/donor-site resurfacing comes from the cited Qin comparison, and the requirement for an adequately vascularised bed (FTSG over periosteum-covered bone, not bare bone) and the FTSG advantages/disadvantages from the cited Soraya case report. The indications for a dermal substitute - wound depth as the primary determinant, the one-stage versus two-stage split, the explicit inclusion of exposed bone or tendon in the two-stage indication, and infection as a contraindication - come from the cited van den Bosch systematic review, which is drawn largely from burn and reconstructive practice rather than from hand-specific trials; the hand application over bone exposed after tumour excision is a single reported case.

Graft thickness is described here as calibrated on the dermatome rather than in millimetres, because no verified thickness ranges were identified; the practical trade-off is stated instead - a thicker graft carries more dermis and so contracts less but takes less reliably and leaves a donor site that heals more slowly. The graft-take phases, the STSG/FTSG properties, the eight rungs of the reconstructive ladder and the reconstructive elevator concept are standard, well-established plastic and hand-surgery teaching. (See also Fingertip Injuries and Wound Closure Techniques; no dedicated flap or soft-tissue-coverage topic exists in the library, which is why the flap rungs are named here rather than deferred.)