Fingertip Reconstruction

Outline1. Aims of reconstruction2. Epidemiology3. Anatomy4. Nail physiology5. Reconstructive options• Heal by secondary intention• Skin grafts• Flap reconstruction -homodigital

-Heterodigital - Local/regional/distant

Aims

• The treatment objectives in fingertip reconstruction are to:

• close the wound• maximize sensory return• preserve length• maintain joint function• obtain a satisfactory cosmetic

appearance

Epidemiology

• Of all traumatic injuries, one third affect the hands, with the fingertips being the most frequently injured portion of the hand (Kelsey, 1980).

• 24% of surgical hand trauma

• Ages 4-30 most common

• 75% of patients-male

Fingertip anatomy• The fingertip is the portion

of the digit distal to the insertion of the flexor and extensor tendons on the distal phalanx.

• From the periosteum of the distal phalanx, fibrous septae anchor the skin and palmar pulp to the bone.

• The volar surface of the fingertips contains grooves and ridges, uniquely patterned for each individual, termed fingerprints.

Anatomy• The volar pulp is also

stabilized by the Grayson and Cleland ligaments, extending from the flexor sheath and distal phalanx volar and dorsal to the neurovascular bundles, respectively.

Arterial supply of the fingertip• The digital arteries

and nerves arborize or trifurcate near the distal interphalangeal joint.

• The proper digital artery crosses the distal interphalangeal joint, sending a branch to the nail fold, nail bed, and finger pad

Venous drainage of the fingertip

Innervation of the fingertip

• Each digital nerve trifurcates near the distal interphalangeal joint, sending branches to the perionychium, fingertip, and volar pad.

• The digital nerves lie volar to the digital arteries near the fingertip.

• The fingertip is the organ of touch and feel and is abundantly supplied with sensory receptors, including Pacinian and Meissner corpuscles and Merkel cell neurite complexes.

Nail Physiology and anatomy• The dorsal surface of the fingertip

comprises the nail fold, nail bed, and nail plate (= perionychium).

• The perionychium includes the entire nail bed and paronychium complex.

• The paronychium is the skin surrounding the nail plate radially and ulnarly.

• The eponychium is the epidermal shelf at the base of the nail.

• The lunula is the white semicircle at the base of the nail bed. The fingernail is a specialized epidermal structure, like hair.

Nailbed production• The proximal one third of the nailbed,

from the nail fold to the edge of the lunula, is the germinal matrix. It has two components, the dorsal and intermediate nail. The two thirds of the nailbed distal to the lunula is the sterile matrix or ventral nail.

• Fingernail production occurs in 3 areas of the nailbed, the dorsal nail and intermediate nail of the germinal matrix and the ventral nail of the sterile matrix. Of these areas the intermediate germinal matrix produces 90% of nail volume. The remainder of the nail substance is produced by dorsal nail of the germinal matrix and ventral nail of the sterile matrix.

Nail growth rates• The dorsal roof of the germinal matrix deposits

cells on the nail surface. • The two thirds of the nail bed distal to the lunula,

the ventral nail or sterile matrix, acts as a conveyor belt for the advancing nail and adds squamous cells to the nail, making it thicker and stronger (Zook, 1994).

• The nail is not merely attached to the bed but rather is a continuum of a single structure from basilar cells in the nail bed.

• Nail growth occurs at a rate of 3-4 mm a month. It takes 3-4 months for growth to full nail length and 1 year for the nail to achieve maximal pre-injury smoothness.

Fingertip injury assessment Level of injury Mechanism Depth of loss Exposed bone/tendon Nailbed support Contamination Patient factors

Healing by secondary intention• If the skin loss is no larger

than about 1.5 cm2 • wound may be allowed to

granulate and heal spontaneously.

• This type of treatment is especially well suited to children and the elderly.

Grafting- Composite graftingReattach part• Outcomeunpredictable• Younger do better• 2 years or less • Can be done in adults

However, when the amputated part is crushed and macerated, this should not be used as a graft.

• As composite tip grafts must initially survive by plasmatic imbibition until neovascularization, revascularization is not reliable for adults and tip grafts should not be reapplied for adults

Skin grafting• Skin graft application is considered for distally

located and volarly directed fingertip wounds without exposed bone or tendon.

• Glabrous or non-glabrous skin• Controversy exists as to whether split- or full-

thickness grafts are better. • split skin grafts take earlier and more reliable

and wounds contract more, resulting in a smaller defect

• full-thickness offer earlier re-innervation and more reliable, durable coverage (Hutchison, 1949; Napier, 1952; Ponten, 1960; Porter, 1968).

What’s the difference?• Glabrous skin provides a

better aesthetic appearance and match of texture and color.

• Glabrous skin can be harvested from the hypothenar eminence or thigh (Patten, 1968).

• Nonglabrous skin can be obtained from the wrist crease, forearm, medial upper arm, or groin.

Local flap options for fingertips

• When bone or tendon is exposed at the base of a fingertip wound, a local flap is required.

• The various local flaps used to reconstruct fingertips include volar V-Y, bilateral V-Y flaps, cross-finger flap, thenar flap, and island flaps.

• Flap choice depends on orientation and configuration of the wound, injured finger, and sex of the patient.

• Surgeons can optimize the reliability of these local flaps by avoiding tension on the suture line and preserving the traversing sub-dermal blood vessels into the flap

Volar V-Y flap

• Though frequently termed the Atasoy flap, Tranquilli-Leali first described the volar V-Y flap in 1935 (Tranquili-Leali, 1935; Atasoy, 1970).

• The volar V-Y flap is a triangular-shaped volar advancement flap outlined with its tip at the distal interphalangeal crease.

• The local flap is most applicable for transverse and dorsal avulsions when a relative abundance of pulp skin is present

• Then the V is scored through the dermis only to avoid injuring the traversing vessels into the triangular-shaped flap

Bilateral V-Y flaps

•The disadvantages of Kutler flaps include partial or complete flap necrosis, risk for pincher nail deformity, and excess scar on fingertip risking hypersensitivity. These disadvantages are increased compared to other flaps.

• In 1947 Kutler described the bilateral V-Y flaps for fingertip injuries.

• Best applied for volar and transverse avulsions with exposed bone when excess lateral skin is present.

• These flaps are designed along the midlateral line and should not extend proximal to the distal interphalangeal joint.

• In raising these flaps the incisions are performed through the dermis only to preserve arborizing vessels.

• The flaps are mobilized for distal advancement by dissecting fibrous septae from the distal phalanx.

The Cross Finger Flap• Originally termed the

transdigital flap by Gurdin and Pangman in 1950, the cross-finger flap is commonly used for volar-directed tip injuries with exposed bone or tendon when insufficient pulp for the volar V-Y flap is present.

• Requires two operations and a skin graft.

• Moreover, the fingers become stiff during the delay between these two stages.

Cross finger flap technique• The flap is elevated from the adjacent finger dorsum in

the plane above the peritenon to allow for grafting of the donor site.

• A full-thickness graft can be taken to close the donor finger dorsum.

• The flap is opened like a book cover, turned 180°, and inset into the fingertip defect. The fingers may be sutured together or even pinned to prevent flap dehiscence.

• During the delay, gentle active range-of-motion exercises are critical to prevent joint stiffness of both fingers.

• At 2-3 weeks the flap is divided and inset and more aggressive active and passive range-of-motion exercises are begun.

Cross finger flap results• The advantages of the cross-finger flap include a

reliable and large flap that can even be innervated (Cohen, 1983). However, several reports describe very good 2-point discrimination (2PD) without innervating the cross-finger flap (Kleinert, 1974; Sturman, 1963; Johnson, 1971).

• The disadvantage to the cross-finger flap is the need for a second operation and the delay that results in stiffness.

• Accordingly, this flap is contraindicated for older patients (>40 y) or those with Dupuytren syndrome or rheumatoid arthritis.

Thenar flap• The classic description of the thenar

flap by Gatewood in 1926 was proximally based (Gatewood, 1926).

• Later, Smith and Albin (1976) described the H-shaped modification of the thenar flap.

• A 2 cm x 4 cm thenar flap can be harvested from the MCP crease and still allow primary closure of the donor site with thumb flexion.

• Care must be exercised in harvesting this thenar flap at the MCP crease to avoid injury to the neurovascular bundles and flexor pollicis longus tendon (Russell, 1981).

Laterally based pedicled flaps• An alternative way to increase the

pulp advancement for more oblique palmar sloping defects is to use single pedicle lateral flaps. The earliest of these lateral flaps was described by Geissendörfer in 1943. This flap was subsequently popularised by Kutler .

• It is vascularised by the small vessels beyond the trifurcation of the digital arteries. These flaps only ever move significantly in the drawings in textbooks

Segmüller & Venkataswami flaps• More useful is the lateral flap described by

Segmüller G. Modifikation des Kutler-Lappens: Neuro-vaskuläre Stielung. Handchirurgie 1976;8:75-6

• Each lateral flap is raised as an island on its own neurovascular bundle and has a much bigger volume and reconstructive potential than the Geissendörfer /Kutler flaps.

• Originally, Segmüller raised the flaps only as far proximally as the DIP joint crease. Lanzetta et al described the use of a modification in which the flap is extended back to the PIP joint.

Difference between them?

• The Segmüller flap can also be bilateral and carries its own innervation while the advancing edge of the Venkataswami flap furthest from the pedicle is denervated.

Reverse digital island flap

• Lai 1989• The reverse digital flap is

an arterialized homodigital flap described by which replaces injured tissue with like tissue from the same digit in a single stage.

• The flap is harvested from the lateral aspect of the proximal phalanx of the same finger, preferably the nonopposition side.

Reverse digital island flap dissection

• The pedicle is harvested with a cuff of soft tissue to include the digital artery venae comitante.

• The digital nerve can be preserved. • The pedicle is harvested to 5 mm proximal to the distal interphalangeal joint

to capture crossover vessels from the contralateral digital artery.• If doubt exists concerning reverse blood supply to the flap, the proximal

digital artery can be temporarily clamped to evaluate retrograde flow to the skin island. The donor site usually requires a skin graft

Local Flaps for the Thumb

• Rectangular volar advancement flap • Though often termed the Moberg flap, the

volar advancement flap was first described by Littler in 1956 before being popularized by Moberg in 1964.

• This is a rectangular volar flap based on both neurovascular bundles.

• The flap is undermined in the distal to proximal direction to the MCP crease superficial to the flexor pollicis sheath and advanced in the distal direction. This flap can usually be advanced 1.5 cm distally.

Complications for fingertip reconstructions

• Major ones are hypersensitivity and cold intolerance,

• The rates of hypersensitivity and cold intolerance approximate 50% regardless of the treatment, including healing by secondary intention, skin grafting, and local flap reconstruction.

• This hypersensitivity and cold intolerance is self-limited and almost always resolves after 1-2 years. Initial treatment includes scar massage, desensitization, and edema control.