Plastic surgery

PART VIII

HAND

CHAPTER 73  SOFT TISSUE RECONSTRUCTION OF THE UPPER EXTREMITY

SCOTT L. HANSEN, PATRICK LANG, AND HANI SBITANY

INTRODUCTION

Soft tissue reconstruction of the upper extremity requires strict adherence to standard surgical principles. In keeping with the reconstructive ladder, options for coverage include primary closure, skin grafting, local flaps, regional flaps, and free tissue transfer. Goals include restoration of a functional, sensate, and aesthetically acceptable hand. In addition, stable coverage of vessels, nerves, tendons, and joints throughout the forearm and arm is required. Primary wound healing is also a fundamental goal as it reduces scar formation and joint stiffness. Among the considerations involved in selecting the proper techniques are the components involved, the size of the defect, the mechanism of injury, and the cleanliness of the wound. Patient factors including handedness, occupation, age, sex, and overall health are also considered.

Classic teaching dictates that soft tissue reconstruction follows skeletal stabilization in the traumatized extremity. After bony fixation, stable soft coverage facilitates wound healing, reduces contracture, decreases infection, and improves outcomes for secondary skeletal operations such as bone grafting or distraction. The attempt to achieve a stable soft tissue envelope begins immediately following injury, as Godina espoused for lower extremity injuries.1 Although definitive soft tissue coverage may not be immediately possible, wound debridement is always performed initially. Early debridement of nonviable tissue reduces the opportunity for local inflammatory response and infection. Serial debridement is performed as many times as necessary to ensure viability of all remaining tissues. Definitive coverage is then performed once the wound is adequately debrided.

When planning definitive coverage, local tissue options are considered. Uninvolved soft tissue of the upper extremity is often superior to more distant tissue, as it offers similar sensibility and tissue match. Unfortunately, there is often a paucity of donor tissue in the upper extremity, especially following significant injuries or extirpative surgery. In such cases, distant tissue options are explored.

Basic wound care principles are as essential as the various grafts and flaps available. These principles allow the crafting of a safe and effective reconstructive plan for the upper extremity. This chapter outlines reconstructive options ranging from simple skin grafts to complex free tissue transfer. There are many instances in upper extremity soft tissue reconstruction where “less is more”—an example being the healing of a fingertip injury by secondary intention, when more complex solutions would prolong impairment. The surgeon must be comfortable with all rungs of the reconstructive ladder if the appropriate reconstruction is to be performed in a wide range of clinical scenarios.

NEGATIVE PRESSURE DRESSING

The use of negative pressure dressings has revolutionized the care of complex wounds. Although some controversy exists regarding its effect on time to heal, there is no debate over the degree of convenience that it has introduced for both the patient and the surgeon. Wounds of the upper extremity requiring serial debridement do well with negative pressure dressings between procedures provided no neurovascular structures are exposed. Thus, negative pressure dressings serve as a bridge to definitive coverage. In addition to the convenience and cleanliness of the dressings, negative pressure has been shown to promote wound contraction, improve local tissue perfusion, and promote the formation of granulation tissue—effects that make definitive reconstruction easier to achieve.2

HEALING BY SECONDARY INTENTION

The goal of upper extremity soft tissue reconstruction is primary wound healing. Healing by secondary intention is occasionally appropriate such as in certain fingertip injuries. As one of the main goals of fingertip reconstruction is the restoration of protective sensibility, this method is helpful in small, superficial tip defects. In such defects, sensation is maintained in the healed tissue as sensate skin is drawn into the defect.3

This is especially helpful for defects in both children and the elderly. Wounds heal more rapidly in children than in adults because of enhanced wound contraction. In the elderly, healing by secondary intention avoids some of the pitfalls of sensate local flaps: prolonged postoperative immobility and resultant joint stiffness, and the avoidance of necessary cortical reinnervation.

Apart from these defects, healing by secondary intention is of little use for soft tissue resurfacing elsewhere in the upper extremity because of the functional limitations from the resultant contracture.

AMPUTATION

Similar to healing by secondary intention, revision amputation is best suited for specific cases of fingertip injuries in select patients. This is often advantageous in those patients eager to return to work, and those with multiple comorbidities or clinically unstable pictures.

Although those injuries of the remainder of the extremity with large amounts of devitalized tissue may also benefit from some degree of select amputation, it is rarely indicated as the primary method for definitive treatment of upper extremity injuries.

SKIN GRAFTS

Stable skin and soft tissue coverage of the hand is essential for hand function. Volar and dorsal surfaces should be considered separate entities when considering coverage. The dorsal hand skin is thin, mobile, and has the primary function of allowing flexion, while maintaining nonadherent coverage of tendons and joints. Split-thickness skin grafts are appropriate for large defects of the upper extremity that have no vital structures exposed. In addition to improved “take” relative to full-thickness skin grafts, split grafts also offer the advantage of greater secondary contraction of the wound, and resultant reduction in the size of the grafted area. The presence of paratenon greatly enhances the survival of the graft and improves postoperative tendon gliding. The ideal thickness for skin grafts to the hand ranges between 0.012 and 0.014 inches. Meshing of the graft can be performed to increase graft surface area, and allow egress of underlying fluid.

FIGURE 73.1. A. Exposed extensor tendons after IV infiltration and serial debridements. B. Reconstruction with Integra followed by delayed coverage with a skin graft.

When resurfacing the dorsal surface of the hand, tendon adhesion to the overlying skin graft may occur, and subsequent tenolysis is often required. The authors have found that large dorsal defects with exposed tendon do well with coverage by Integra Dermal Regeneration Template, followed by split-thickness skin grafting (Figure 73.1). Other biologic templates may also be comparable and should provide the benefits of improved coverage and reduced adherence to underlying gliding tendons. Though not appropriate for all wounds, elderly patients or those with significant comorbidities precluding free tissue transfer can be reconstructed using this method.

The glabrous skin on the volar surface of the hand carries a highly specialized tactile sensory function. Because of the mechanical demand placed on the working palm, the volar skin is thick and densely adherent to the underlying fascial system, through a series of vertical ligaments. For defects involving the volar hand, primary options for resurfacing include full-thickness glabrous skin grafts from either the hypothenar eminence or the non–weight-bearing region of the plantar foot. This offers the advantage of also providing specialized nerve endings, similar to those encapsulated nerve endings in the injured volar skin, and donor sites that may be closed primarily. If necessary, full-thickness grafts for such defects may also be obtained from other areas of the upper extremity. Given that the native volar skin is devoid of pilosebaceous structures, every effort should be taken to harvest the grafts from similarly hairless areas, such as the volar wrist, or the skin just proximal to the medial epicondyle of the elbow.

Skin grafting of forearm and proximal arm defects follows a similar algorithm to dorsal hand grafting. The majority of defects can be adequately covered with meshed split-thickness grafts. Skin grafting is also an option for fingertip defects. While full-thickness skin grafts are sometimes useful for tip coverage, they are rarely a preferred primary method due to poor recovery of sensibility. In most cases, a sensate flap is a better option, as it retains the important protective sensibility of the fingertip.

LOCAL FLAPS

Bilateral V-Y Advancement Flap

Transverse and volar fingertip injuries can be treated with bilateral V-Y advancement flaps (Figure 73.2). As described by Kutler, these flaps are elevated from the sides of the injured digit and advanced distally.4 Because mobility is limited, division of the vertical fibrous septa is crucial to obtain adequate advancement. The terminal branches of the neurovascular bundles lie in the lateral pulp tissue of the flap, and thus, careful attention must be taken to avoid their injury during undermining. In cases where complete closure cannot be achieved due to inadequacy of advancement, the flaps can be advanced maximally, and the remaining wound can be allowed to heal by secondary intention. Due to the limited mobility of these flaps, use of the V-Y advancement flaps is usually reserved for defects distal to the midnail level.

Volar V-Y Advancement Flap

Closure of transverse or dorsally angulated fingertip injuries can often be achieved with the use of a volar V-Y advancement flap (Figure 73.3). Described by Atasoy and Kleinert, this is a V-shaped flap with the tip at the distal interphalangeal crease which is advanced distally, to achieve tension-free closure.5 Like the bilateral V-Y advancement flaps, the volar advancement flap requires division of the fibrous septa from the distal phalanx to achieve adequate advancement. Expected advancement, when incision is entirely distal to the DIP flexion crease, is 1 cm. When properly planned, the entire donor defect can be closed primarily with little tension.

FIGURE 73.2. Kutler flap. Bilateral triangular advancement flap for patients with transverse or volar oblique amputations.

FIGURE 73.3. Atasoy flap. Volar V-Y advancement flap.

Volar Neurovascular Advancement Flap (Moberg Flap)

Fingertip amputations can be covered with distal advancement of the entire volar finger skin as a single neurovascular flap (Figure 73.4). The volar digital neurovascular advancement flap has been described for use in all digits, but Moberg popularized its use for transverse amputations of the thumb, a procedure that persists today as the most common application of this flap.6 Two parallel longitudinal incisions are made dorsal to the neurovascular bundles, followed by elevation of the flap off of the flexor tendon sheath. The flap is designed with its base at the metacarpal phalangeal crease and advanced distally with its neurovascular bundles intact. The true Moberg flap requires splinting with some degree of flexion to allow for tension-free healing of the advanced flap. This can create problems with stiffness, particularly in older patients. Modifications include the creation of a true island flap with skin grafting of the resulting proximal defect, which may increase advancement to 1.5 cm. Alternatively, flap design into the web space proximally may increase advancement to 3.0 cm.7

This flap should be avoided in non-thumb digits due to tenuous dorsal skin perfusion following the required longitudinal incisions. It is the unique dorsal and volar blood supply of the thumb that allows for safe elevation of this flap.

Cross Finger Flap

Volar fingertip pulp amputations can be treated with the cross finger flap. Gurdin and Pangman first described the use of dorsal skin and subcutaneous tissue from an adjacent finger for volar defect coverage.8 The flap is designed over the dorsum of the middle phalanx and elevated off the underlying extensor paratenon. Preservation of the paratenon over the extensor apparatus is critical. The flap is then turned over to resurface the volar tip of the adjacent (injured) finger (Figure 73.5). The pedicle can be designed laterally, proximally, or distally. The donor site is skin grafted (full-thickness graft) and both digits are immobilized. Because this flap acts as a vascularized full-thickness flap of skin, it may be safely divided within 2 weeks; thus, stiffness of the immobilized digits is minimized.

FIGURE 73.4. A. Moberg flap. Design of the homodigital advancement flap to cover defects of the thumb pulp. B. Advancement of Moberg flap to cover thumb pulp defect.

Complications associated with the cross finger flap include poor aesthetics at the donor site, stiffness due to prolonged immobilization, and cold intolerance of the donor digit. In addition, the recipient digit will always have relatively poor sensibility.

Reverse Cross Finger Flap

Dorsal digital wounds can be covered with use of the reverse cross finger flap (Figure 73.6). This flap consists of subcutaneous tissue elevated from the dorsum of the middle phalanx of the adjacent finger. This is exposed by first elevating the skin of the donor digit in this region, maintaining a base laterally, on the side opposite the injured digit. The flap is turned over to cover the dorsal defect of the injured finger. The elevated skin from the donor digit is then sutured back into its native position and the flap on the injured digit is skin grafted. Delayed division of the pedicle is generally performed at 2 weeks.

Thenar Flap

The thenar flap is an excellent and reliable choice for reconstruction of distal phalanx soft tissue defects and amputations (Figure 73.7). This flap stands in contrast to the historically complication-ridden palmar flap, described by Gatewood, which resulted in frequent proximal interphalangeal (PIP) joint contracture.9 Beasley established four guidelines for proper execution of the thenar flap in an attempt to limit complications associated with the related palmar flap: (1) the metacarpal phalangeal joint of the recipient finger is fully flexed in an attempt to limit required flexion of the PIP joint; (2) the thumb is placed in full palmar abduction or opposition; (3) the flap is designed with a proximal pedicle high on the thenar eminence so that its lateral margin is at the metacarpophalangeal skin crease; and (4) the pedicle is divided after 10 to 14 days.10

In addition to these principles, the flap should generally be 1.5 times the diameter of the injured fingertip. This enables preservation of the rounded contour of a normal fingertip. The donor site can often be closed primarily, but will occasionally require placement of a skin graft.

FIGURE 73.5. A. Cross-finger flap. Elevation of cross finger flap to reconstruct a defect on an adjacent digit. B. Cross-finger flap. Inset of the cross finger flap on the adjacent thumb pulp defect with coverage of the donor site with a split-thickness skin graft.

Following pedicle division, active and aggressive rehabilitation of the finger must be commenced to prevent finger stiffness and joint contracture. Although there may be a higher risk of joint contracture in those patients older than 40 years following a thenar flap, they have been used in patients of all ages with reports of minimal morbidity.11

FIGURE 73.6. A. Reverse cross-finger flap. Elevation of the epidermis. B. Elevation of reticular dermis and subcutaneous tissue flap and rotation to the adjacent dorsal finger defect. C. Inset of the flap over the exposed DIP joint of the dorsal index finger and coverage of the donor site with the previously elevated epidermis.

Neurovascular Island (Littler) Flaps

In 1960, Littler described transfer of vascularized, sensate tissue from the ulnar border of the long or ring finger for reconstruction of volar thumb pulp.12 These neurovascular island flaps are based on the digital artery and proper digital nerve of the donor finger. The artery is dissected proximally to the level of the palmar arch, and the nerve is freed from its adjacent digital nerve at the level of the common digital nerve. The flap is transferred to the volar thumb on its pedicle in a single-stage fashion (Figure 73.8).

FIGURE 73.7. A. Thenar flap. Transverse index finger defect with exposed bone. Preparing to design the proximally based thenar flap. B. Inset of the index finger tip into the thenar flap prior to division at 2 weeks.

Having adequate sensation in the volar thumb is associated with better functional outcomes. Unfortunately, this requires cortical reeducation which is reported to occur in only 40% of cases.13 Another drawback of this flap is the donor finger sensory deficit, secondary to the necessary division of the ipsilateral distal digital nerve. Following flap mobilization, the resultant defect on the donor digit is skin grafted.

FIGURE 73.8. A. Littler flap. Design of the neurovascular island pedicle flap. B. The neurovascular island flap tunneled to volar thumb defect with coverage of the donor site with a split-thickness skin graft.

First Dorsal Metacarpal Artery Flap

The first dorsal metacarpal artery (FDMA) flap is a sensate, fasciocutaneous flap, harvested from the skin of the dorsal surface of the hand, index finger, and thumb. It is used primarily in reconstruction of ulnar side defects of the volar thumb pad.14,15 It is also indicated for severe first web space contractures with irregular surfaces and exposed neurovascular structures. The skin of the FDMA flap is particularly durable and flap sensibility is comparable to that of the Littler flap. Though the reversed-flow flap has been described for coverage of skin defects up to the distal phalanx of the index finger, this should not be used as a first choice, due to unreliable perfusion.

The branches of the FDMA run close to the first metacarpal bone, in the middle of the first interosseous space. Two venae comitantes are present around the artery, and drain into the superficial venous system.

During dissection of this flap, it is important not to include the skin over the index finger metacarpal neck. This helps to avoid web space contracture. If the skin in this area is necessary to cover the skin defect, the flap is extended ulnarly toward the long finger metacarpal. Following flap elevation and transfer, the donor site is covered with a skin graft (Figure 73.9).

The FDMA flap, taken in antegrade fashion, offers a reliable option for sensate thumb reconstruction. With a constant anatomy and expendable artery, its use in hand reconstruction can reduce the need for many of the distant pedicled flaps covered later in this chapter.

REGIONAL FLAPS

Radial Forearm Flap

The radial forearm flap is a versatile fasciocutaneous flap that can be used to reconstruct a wide range of upper extremity defects (Figure 73.10). As a pedicled flap it may be used in a standard or reversed fashion to provide reliable coverage of the forearm, elbow, wrist, hand, and thumb. As a free flap, it is even more versatile. Robust septocutaneous perforators from the radial artery allow for a wide range of skin paddle shapes and sizes. The donor site can be skin grafted with minimal morbidity, provided the paratenon of the underlying tendons is preserved. Even with adequate skin grafting, however, the donor sites are aesthetically problematic.

The distally based reverse radial forearm flap is a useful modification for distal defects. This flap is based on the radial artery and its accompanying venae comitantes, which drain the flap in a retrograde manner. For this modification of the flap, arterial inflow is supplied through the ulnar artery, and the superficial palmar arch. A preoperative Allen test is essential prior to any radial forearm flap harvest in order to ensure that the hand will remain perfused following radial artery harvest (Figure 73.11).

Whether using a standard or retrograde approach, care should be taken to avoid injury to the superficial radial sensory nerve. Injury of this nerve or its branches may lead to significant paresthesias and postoperative pain. In addition, when raising the proximally based radial forearm flap, the cephalic vein may be maintained within the flap such that venous drainage will be augmented. In order to include the cephalic vein, the flap must extend on to the dorsal aspect of the radial side of the arm.

Posterior Interosseous Flap

The posterior interosseous flap has a range of applications similar to that of the radial forearm flap. With its dorsal donor site skin paddle supplied by septocutaneous perforators from the posterior interosseous artery, this fasciocutaneous flap can cover a wide range of defects of the elbow, forearm, wrist, dorsal hand, first web space, and thumb.16

The primary contraindication to use of this flap is in cases of significant wrist or forearm injury, as there is an increased risk of PIA thrombosis. The flap can also be harvested with functional muscle or vascularized tendon. Like the radial forearm flap, a distally based reverse flap is useful for coverage of distal defects.

Medial Arm Flap

The medial arm flap is a reliable coverage option for fasciocutaneous defects of the axilla and antecubital fossa. Based on branches of the superior ulnar collateral artery, the standard flap design allows rotation into the axilla. Antecubital defects can be covered with a reverse flap pedicled on the posterior ulnar collateral vessels. A relatively smaller skin paddle can be elevated as a free flap for transfer throughout the body, including the upper extremity. The medial arm donor site can often be closed primarily, although skin grafting is necessary for larger flaps.

FIGURE 73.9. A. First dorsal metacarpal artery flap. Flap design over the proximal phalanx of the dorsal index finger and rotation to a volar thumb defect. B. Inset of the flap with split-thickness skin graft coverage of the donor site.

FIGURE 73.10. A. Radial forearm flap to elbow. Degloving injury of the upper extremity with open elbow joint. B. Elevation of flap and rotation to defect. C. Stable soft-tissue coverage of elbow.

Lateral Arm Flap

The lateral arm flap is another regional fasciocutaneous flap that provides good coverage for upper extremity defects. The standard flap, based on the radial collateral artery, can provide an adequate arc of rotation for coverage of axillary and shoulder wounds. The reverse flap, based on the radial recurrent artery, can be used as a pedicled flap for elbow coverage. Additionally, a segment of vascularized humerus or triceps tendon can be taken with the standard flap design for reconstruction of composite defects. Like the medial arm flap, the lateral arm flap can be harvested as a free flap for coverage of more distant upper extremity defects, such as those of the hand.

Obesity and the presence of epicondylitis or other inflammatory elbow diseases generally preclude the use of this flap.

Latissimus Dorsi Flap

The latissimus dorsi muscle can be used to reconstruct soft-tissue defects of the shoulder, upper arm, elbow, and forearm.17,18 It carries the advantage of being a large, expendable muscle with a significant arc of rotation. This is due to the significant length of its thoracodorsal vascular pedicle. In addition to harvest of the muscle as a pedicle flap, harvest as a myocutaneous flap is common. In order to reach distal arm defects, it is necessary to ligate the vascular branch to the serratus muscle. In addition, it is necessary to separate the muscle from its insertion on the humerus, as well as transect the thoracodorsal nerve. Harvesting this muscle often is not associated with functional problem and the donor scar is less conspicuous and more acceptable when compared to the radial forearm flap.

Transfer of the muscle with preservation of the thoracodorsal nerve and humeral insertion can also be performed for use of the muscle as a neurotized flap. This is often used for restoration of shoulder and elbow function.

DISTANT FLAPS

Distant flaps are based on anatomically defined pedicles. As such, they are performed in a two-stage procedure, with pedicle division and flap inset occurring at the second stage. As they are supplied by a named arterial, they offer a robust and reliable blood supply. These flaps are especially useful for coverage of large defects of the hand.

Superficial Inferior Epigastric Artery Flap

Based on the superficial inferior epigastric artery (SIEA), which ascends onto the abdomen from its origin at the femoral artery, this flap was first described as an inferiorly based tubed flap for hand coverage.20 Given its vertical orientation, donor sites up to 10 cm width can be closed primarily. Flap harvesting from the side contralateral to the injured hand allows the involved upper extremity to sit more comfortably during the 2- to 3-week period of immobilization prior to pedicle division (Figure 73.12).

FIGURE 73.11. A. Reverse radial forearm flap. Degloving injury of dorsal hand with unstable soft-tissue coverage and contracted first web space. B. Debridement of unstable tissue and release of the first web-space contracture with resulting defect. C. Design of the reverse radial forearm flap. D. Stable soft-tissue coverage of the dorsal hand defect.

Superficial Circumflex Iliac Artery Flap

Known also as the groin flap, the superficial circumflex iliac artery flap is based on the superficial circumflex iliac branch of the femoral artery.19 These flaps may be designed widely in the inguinal region, and donor sites up to 14 cm can be closed primarily. It is based medially, usually on the side ipsilateral to the injured hand. This results in more difficult and uncomfortable immobilization than the contralateral SIEA flap, as the shoulder must be rotated externally. However, relative to the SIEA, the groin flap usually can be designed in an area with minimal hair growth.

Contraindications to using the groin flap include patients with chronic groin infections (e.g., intertrigo), and those with lower extremity or upper extremity edema (relative contraindication). In addition, preservation of the lateral femoral cutaneous nerve is critical to avoiding prolonged pain and dysesthesia postoperatively.

Random Pattern Flaps. The so-called random pattern flaps are those based on smaller, unnamed vascular pedicles. As such, they must be smaller. When derived from the abdomen, they may be based in any direction.

Another source of random pattern cutaneous flaps for upper extremity reconstruction is the contralateral arm. The medial surface of the contralateral upper extremity is often a supple, well-vascularized source of tissue. As with random abdominal pattern flaps, these flaps should be made small. However, contralateral arm flaps provide a better color and tissue match, with less hair-bearing potential.

Microvascular Free Tissue Transfer. Free tissue transfer provides robust, vascularized tissue for coverage of a wide variety of upper extremity defects, including composite defects. Specific indications for use of this method in upper extremity reconstruction include an inadequacy of donor tissue around the zone of injury, large defect size, exposed hardware, and anticipated postoperative radiation therapy.

In light of the end-organ arterial anatomy of the upper extremity, end-to-side anastomoses for tissue transfer may be required in many cases. However, provided superficial palmar arch patency is confirmed (Allen test), radial or ulnar artery ligation may be feasible for completion of an end-to-end anastomosis. For venous outflow, either the venae comitantes of the arteries or the superficial veins (cephalic, basilic) can be used.

Latissimus Dorsi Flap

The latissimus dorsi muscle can be harvested in full or in part as a free flap for coverage of upper extremity defects.21 A large, reliable skin paddle can be included. Advantages of the latissimus flap for upper extremity coverage include its relative thinness, making it ideal for achieving an aesthetic contour in the upper extremity, and its consistently long pedicle (up to 15 cm).

FIGURE 73.12. A. Superficial inferior epigastric artery flap. Chronic forearm wound with exposed ulna and osteomyelitis. Design of flap. B. Elevation of the flap. C. Inset of the flap into the defect with primary closure of the donor site. D. Stable soft-tissue coverage after flap division.

Although the latissimus should always be harvested based on the thoracodorsal vessels, it is possible to preserve a leash of the serratus branch during dissection. This branch can be utilized as a secondary source for anastomosis if necessary (Figure 73.13).

Rectus Abdominis Flap

The rectus abdominis muscle or musculocutaneous flap is a reliable flap for use in a variety of upper extremity reconstructive scenarios. Based on the deep inferior epigastric artery, the muscle can be transplanted to provide vascularized bulk for coverage of large soft tissue defects (Figure 73.14). The rectus flap is particularly useful in instances of hardware exposure or previous underlying osteomyelitis. Free muscle without the overlying skin paddle is covered with a split-thickness skin graft. Disadvantages of the rectus abdominis flap include a large visible scar in the abdomen, and the potential for abdominal wall morbidity, including bulge or hernia formation.

Although this flap can be based on either the superior or inferior epigastric vessels, the inferior vessels are generally preferred. When taken just beyond their origin from the external iliac vessels, they offer a much larger caliber than the superior epigastric vessels.

Gracilis Flap

The gracilis flap, based on the medial circumflex femoral vessels, is another muscle or musculocutaneous flap with wide application to the upper extremity. Advantages include its relatively concealed donor site with little donor site functional deficit. In addition, the close proximity of the obturator motor nerve to the vascular pedicle makes the harvest of the entire neurovascular pedicle efficient. In cases involving significant neuromuscular deficits, the gracilis can be harvested as a functional muscle for reestablishment of basic upper extremity motion such as wrist or elbow flexion. Accordingly, the flap has gained popularity for correction of motor deficits due to brachial plexus palsy, and treatment of Volkmann contracture.22

Anterolateral Thigh Flap

Since Song first described the use of the anterolateral thigh (ALT) flap in 1984, perforator-based fasciocutaneous flaps have come to play an increasingly important role in soft tissue reconstruction of the upper extremity (Figure 73.15). Their versatility and low donor site morbidity have led many surgeons to abandon traditional musculocutaneous flaps in a variety of upper extremity defects. We have found the ALT flap to be particularly useful in the upper extremity as the flap can be harvested reliably, and the donor site can often be closed primarily. Flap sizes up to 8 × 25 cm are reliable, but may require skin grafting at the donor site.23 The primary disadvantage of the ALT flap for upper extremity coverage is contour irregularity related to the flap’s relative bulk, particularly in western populations. In these circumstances, a secondary flap debulking is often required.

FIGURE 73.13. A. Latissimus dorsi flap. Mutilating trauma to the upper extremity. B. Wound after serial debridements. C. Microsurgical transfer of the latissimus dorsi muscle. D. Long-term follow-up showing stable wound coverage.

The descending branch of the lateral circumflex femoral pedicle generally yields one to three significant perforators to the overlying skin. However, this flap can be perfused reliably based on one perforator. Should additional soft tissue bulk be necessary, the vastus lateralis muscle can be included in the flap on the continuation of the descending vascular pedicle, thus creating a chimeric flap.

FIGURE 73.14. A. Rectus abdominis flap. Degloving injury of dorsal hand with open metacarpal fractures. B. Elevation of the rectus abdominis flap through a paramedian incison. C. Long-term follow-up showing stable soft-tissue coverage.

FIGURE 73.15. A. Anterolateral thigh flap. Traumatic avulsion of thumb with large soft-tissue deficit. B. Design of the anterolateral thigh flap. C. Stable flap coverage of volar hand in preparation for delayed toe transfer. D. Harvest of second toe in preparation for thumb reconstruction. E. Long-term follow-up.

Deep Inferior Epigastric Artery Perforator Flap

The abdominal wall is a large potential source of free donor tissue. Perforator flaps based on the deep inferior epigastric artery (DIEP) have traditionally been described for use in breast reconstruction, but may also be applied to upper extremity reconstruction. The true DIEP flap spares the rectus muscle and thus results in no functional deficit at the donor site. Muscle dissection can be avoided altogether with a fasciocutaneous flap based on the superficial inferior epigastric vessels. Both flaps can be considered in the algorithm for reconstruction of large upper extremity soft tissue defects requiring significant bulk.

Temporoparietal Fascia Flap

In cases where a thin, pliable flap is needed to provide a vascularized bed onto which a skin graft may be placed, the temporoparietal fascia flap is an excellent option. This is especially useful on dorsal hand defects with exposed tendon. It is also useful for secondary tendon and nerve reconstructions, as well as small three-dimensional defects in the hand (e.g. after first web space release).

The flap is harvested based on the superficial temporal vessels that run just deep to this fascia above the zygomatic arch. The donor site is closed primarily, and following inset of this flap, it is skin grafted for coverage. The main advantages of this flap is its pliability which provides appropriate contour and shape without the need for debulking often attendant with other flaps.

Microneurovascular Partial Toe Transfer

Partial toe transfer is a useful option in select cases of traumatic or surgical loss of finger pad, or to resurface an insensitive or atrophic pulp. The use of the free pulp transfer in such cases is reserved for situations where the use of a local heterodigital or distant flap is not possible. These situations may occur in cases with extensive tissue loss, or when it is not possible to obtain usable skin cover of the thumb or index finger.24 One advantage of these flaps is avoidance of the cold intolerance at the donor site frequently noted following harvest of a heterodigital island flap.

This procedure allows transfer of pulp from the big toe with the digital neurovascular bundle. The larger plantar nerve for the big toe is more suitable than the second toe to match the size of the nerves in the fingers. Most commonly, the ipsilateral foot is used for thumb reconstruction, and the contralateral foot’s big toe for index reconstruction. Transfer of the pulp from the big toe yields a two-point discrimination from 7 to 18 mm, assuming a strict sensory reeducation program is followed postoperatively.25

Other Flaps

There are a number of other free flaps that we view as secondary options for upper extremity reconstruction. These include the scapular and parascapular flaps, serratus anterior muscle flap, the first web space flap, and the dorsalis pedis flap.26 While all are useful, they have been replaced by more anatomically reliable flaps with a more efficient harvest.

Also useful for coverage of fingertip injuries or small defects of the hand are venous flow-through flaps. These offer the advantage of small, pliable skin islands that conform well to the surface of the hand. In addition, they offer a very high success rate regarding flap survival. These flaps are easily harvested, and the veins offer an excellent size match to recipient vessels in the hand. In addition, they result in minimal donor site morbidity. Common donor sites include the volar forearm, the dorsal digits or hand, and the dorsal foot. These flaps are especially useful in difficult replantations with vessel damage, and in fingertip resurfacing.27

Most commonly, the venous flow-through flap is constructed as an arterialized venous conduit flap between two arteries (functionally reconstructing the artery). Additionally, they may be designed between an artery and a vein (as is typical for an A-V fistula). Less commonly, they may also be interposed between two veins as a total venous perfusion flap. Such a design, however, leads to greater size restriction than an arterialized flap, due to the low oxygen delivery from the venous inflow (Figure 73.16).

FIGURE 73.16. A. Venous flap to thumb. Chronic dorsal thumb wound with exposed extensor tendon. B. Debridement of dorsal thumb wound and creation of defect template. C. Template of defect drawn on volar forearm based on superficial venous system. D. Immediate result after microsurgical anastomoses. E. Long-term follow-up showing stable wound coverage and excellent extension of thumb.

References

1.  Godina M. Early microsurgical reconstruction of complex trauma of the extremities. Plast Reconstr Surg. 1986;78:285-292.

2.  Orgill DP, Bayer LR. Update on negative-pressure wound therapy. Plast Reconstr Surg. 2011;127:105S-115S.

3.  Louis DS, Palmer AK, Burney RE. Open treatment of digital tip injuries. J Am Med Assoc. 1980;244:697-698.

4.  Kutler W. A new method for finger tip amputation. J Am Med Assoc. 1947;133:29.

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