The appearance of a glabrous graft can be concerning at 1 to 2 weeks as the thick stratum corneum sloughs. This can give the impression that the graft has failed to take. It does, however, regrow in most cases, so it may be helpful to warn the patient and the nursing staff about this before surgery. Glabrous skin grafts can be useful for defects on the palm. They should be harvested from the hypothenar eminence or from a non–weight-bearing part of the foot such as the instep (rather than the heel). Split-thickness skin grafts are best used as sheet grafts to minimize contraction and improve cosmesis when reconstructing the hand. This is especially true for larger areas on the dorsum, such as burns where early grafting is also prioritized over many other body areas. There are benefits to using split- versus full-thickness grafts in general. Split-thickness grafts show less primary contraction than full-thickness grafts, but are more prone to later secondary contraction. Full-thickness grafts are the reverse, so they provide less secondary contraction over time. Split-thickness graft donor sites have to heal by the process of reepithelialization, where full-thickness graft donor sites are closed directly. Split-thickness grafts can provide cover for much larger defects and graft take can be more predictable. Smaller defects are best reconstructed with full-thickness grafts where possible, as a better color and texture match is achieved. Furthermore, the skin cover is likely to be more robust which is highly relevant to the hand and upper limb. Most potential full-thickness graft donor sites are suitable, provided hair-bearing skin is avoided. Common sites include the upper arm, forearm, groin, and supraclavicular fossa. The contralateral upper limb should generally be avoided as both limbs will have temporary limited function which makes activities of daily living difficult for the patient. It is often possible to use the same limb as a donor for smaller grafts by harvesting skin from the forearm or medial arm.1–3
2. Thorne CH, ed. Grabb and Smith’s Plastic Surgery. 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2014
3. Hallock GG, Morris SF. Skin grafts and local flaps. Plast Reconstr Surg 2011;127(1):5e–22e LOCAL FLAPS FOR FINGER RECONSTRUCTION 2. Which one of the following is correct regarding local flaps used to reconstruct the digit? Homodigital island flaps require sacrifice of one digital vessel; therefore, they are contraindicated in single-vessel digits. They can be useful for reconstructing fingertip defects unsuitable for skin grafts or healing by secondary intention. The neurovascular bundle is dissected proximally to the basal digital crease or into the palm and the flap is advanced in a V-Y or step-cut fashion. Kutler1 flaps are two small lateral V-Y flaps that are usually indicated in selected cases for primary repair of transverse or lateral oblique injuries. A good indication is for secondary revision of fingertip amputations. The Atasoy2 flap is a small volar V-Y advancement flap indicated for dorsal oblique injuries and some transverse amputations. It is contraindicated in volar oblique injuries, as the flap should not extend proximal to the distal interphalangeal joint crease. It should be elevated in the plane just above the periosteum in order to preserve vascularity. The reverse cross-finger flap usually involves raising a thin (subdermal) skin flap away from the defect site (which is later replaced in situ) followed by raising a subcutaneous flap in the opposite direction at the level of paratenon to cover the defect. Alternatively a de-epithelialized skin flap can be raised toward the defect. It is indicated for coverage of exposed tendon or bone on the dorsum of an adjacent digit. A standard cross-finger flap is used for volar defects. The Moberg flap is contraindicated in finger reconstruction because of the risk to the blood supply of the dorsal skin. It is generally indicated for volar defects of the thumb tip/pulp.3
This defect may be adequately reconstructed using a reverse radial forearm flap, but the donor-site scarring is a real disadvantage in a young female patient.1 Other locoregional reconstructive options for this defect include the posterior interosseous and ulnar artery–based flaps, such as the Becker2 flap, but each of these are also likely to require a skin graft to the donor site. For this reason, free tissue transfer with a thin pliable fasciocutaneous flap such as an anterolateral thigh flap or scapula flap may be better for this patient. The posterior interosseous flap3 may leave a numb patch on the forearm if the posterior, medial, or lateral antebrachial cutaneous nerves are divided during flap harvest. The posterior interosseous nerve should not be divided when using this flap. An Allen test is performed to confirm that the hand is perfused independently by the radial and ulnar arteries. It involves manually occluding the radial and ulnar arteries at the wrist, then releasing them in turn while assessing perfusion of the digits. It is not a test of flap viability. When designing the reverse radial forearm flap, it is important to remember that skin perforators are predominantly found in the proximal and distal forearm with a relative paucity in the middle, so ideally the skin paddle should avoid the middle third.
5. Dellon AL. The extended palmar advancement flap. J Hand Surg Am 1983;8(2):190–194
The posterior interosseous artery (PIA) flap was originally described in 1985 and some modifications have been presented.1,2 When used as a pedicled flap to cover defects in the hand, the PIA flap is based on reverse flow in the posterior interosseous artery. The PIA courses between the extensor carpi ulnaris (ECU) and extensor digiti minimi (EDM) in the forearm, and proximally this course is oblique. This means that dissection is safer and easier from distal to proximal to reduce the chance of injuring the perforators supplying the proximal skin flap. The skin paddle is designed over the dorsal forearm at around the junction between the proximal and middle third along a line made between the distal radioulnar joint and the lateral (not medial) epicondyle (Fig. 90.2). The donor site is highly visible. Flaps up to 5 cm in width will usually close directly, otherwise a skin graft is required. The markings should be performed with the elbow flexed, not extended. The pivot point for this flap is 2 cm proximal to the ulnar styloid, so adequate reach must be confirmed before flap elevation. The PIA emerges on the interosseous membrane 5 to 6 cm distal to the lateral epicondyle. It arises from the ulnar and not the radial artery. Posterior artery Flap Pivot Defect Pivot point Ulnar styloid Posterior artery (cut) Vascular pedicle Cutaneous branches Fig. 90.2 Bony landmarks and locations of skin paddle for the reverse posterior interosseous artery flap.
The lateral arm flap is based on the posterior radial collateral artery (Fig. 90.3). It can be pedicled to cover defects of the shoulder and proximal arm. It is also a popular choice for free tissue transfer to the hand because it restricts surgery to a single limb and the donor site can be closed directly. Because of its reach, reconstruction of elbow defects could only be undertaken as a free tissue transfer. In contrast, the reverse lateral arm flap is based on the radial recurrent artery and is useful for elbow reconstruction as a pedicled flap. Again, a key advantage is that the donor site is within the same operative field, as the defect and the scarring can be kept to a single limb. A disadvantage is that the arc of rotation may not always allow complete elbow defect coverage.1 A flexor carpi ulnaris muscle flap is based on the posterior ulnar recurrent artery and can be useful in some elderly patients who require 3 to 4 cm of muscle cover at the elbow. However, this flap should be avoided in young or active patients because of the important contribution this muscle makes to power grip and the “dart-throwing” motion that the wrist makes during many manual activities.2 The radial forearm flap is based on the main radial artery rather than the posterior radial collateral artery. This can be used as a pedicled flap for elbow reconstruction and is probably the most popular choice for significant defects as it is thin, pliable, reliable, and fairly quick to perform, even under regional block. The brachioradialis flap is based on a branch of the radial recurrent artery. It can be used to reconstruct small elbow defects, but this muscle is an important elbow flexor and should be preserved where possible.2–4
The scapular and parascapular flaps are reliable, thin, pliable fasciocutaneous flaps useful for upper limb reconstruction. They are both supplied by cutaneous branches of the circumflex scapular vessels and differ slightly in their skin paddle location and precise blood supply. The scapular flap is supplied by the transverse branch of the circumflex scapular artery, while the parascapular flap is supplied by the descending branch. The skin paddle for the scapular flap is therefore positioned transversely over the middle part of the scapula, while the parascapular flap skin paddle is positioned along the lower lateral border of the scapula. The donor site is generally closed directly and is well hidden in clothing. The lateral border of the scapula may be harvested where bone is needed. The serratus muscle flap is more commonly harvested in conjunction with a latissimus dorsi or bony scapular flap but can be harvested individually where a small muscle flap is required. This muscle is important in the Deep brachial artery Brachial artery Radial recurrent artery Reverse lateral arm flap (forearm flap) Lateral arm flap Posterior radial collateral artery Fig. 90.3 The reverse lateral arm flap (forearm flap) and lateral arm flap, showing the different vascular supplies. stabilization of the scapula, so must not be sacrificed in its entirety. However, the last three digitations can safely be raised without functional impairment. The serratus receives its blood supply from a number of different sources, but the component harvested for free tissue transfer is based on the serratus branch of the thoracodorsal artery. This is why it can be raised along with a latissimus dorsi flap. The gracilis flap is a real workhorse flap for both static and functional reconstruction in the upper limb. It is an excellent flap for achieving dynamic elbow flexion following brachial plexus injury. It is generally raised as a muscle-only flap and is an ideal donor because morbidity is low, with no discernible functional loss and a well-hidden scar passing along the medial thigh. The blood supply to the gracilis is the medial femoral circumflex (which is a branch of the profunda femoris). The muscle differs in size according to age and sex but typically provides 6 × 20 cm of muscle in adult males. It is possible to take a skin paddle with the gracilis, although a longitudinal paddle is generally considered to be unreliable. A transverse proximal skin paddle may be taken as a transverse upper gracilis flap when skin is required. This is more often used for breast or perineal reconstruction. Other useful free flaps for upper limb reconstruction include the anterolateral thigh flap (lateral circumflex femoral vessels), the pectoralis major and pectoralis minor muscle flaps (thoracoacromial vessels), and the rectus abdominis muscle flap (deep inferior epigastric vessels).1,2