The therapeutic challenges of degloving soft-tissue injuries.

BACKGROUND: Degloving soft-tissue injuries are serious and debilitating conditions. Deciding on the most appropriate treatment is often difficult. However, their impact on patients' outcomes is frequently underestimated.
OBJECTIVES: We aimed to study the incidence, clinical presentation, management and outcome of degloving soft-tissue injuries.
MATERIALS AND METHODS: We conducted a narrative traditional review using the key words; degloving injury and soft-tissue injuries through search engines PubMed, Science Direct, and Scopus.
RESULTS: There are several therapeutic options for treating degloving soft-tissue injuries; however, no evidence-based guidelines have been published on how to manage degloving soft-tissue injuries, although numerous articles outline the management of such injuries.
CONCLUSION: Degloving soft-tissue injuries are underreported and potentially devastating. They require early recognition, and early management. A multidisciplinary approach is usually needed to ensure the effective rehabilitation of these patients.

INTRODUCTION

Degloving soft-tissue injuries are a form of avulsion of soft tissue, in which an extensive portion of skin and subcutaneous tissue detaches from the underlying fascia and muscles. Such injuries can affect every part of the body, but in particular the limbs, trunk, scalp, face, and genitalia [Figure 1].[123] In addition to local tissue injuries, severe concomitant injuries and massive blood loss typically occur, so the degloved skin and soft tissue are often effectively dead.

Figure 1

Degloving injury of the right leg that required defatting of the skin

Prompt recognition of degloving soft-tissue injuries is essential, yet treatment is time-consuming and often delayed. Thus, severe degloving injuries, if not recognized may progress to infection or even to necrotizing fasciitis [Figures 2 and 3]. The severity of complications depends on the mechanism, the concomitant injuries, and the anatomic side affected and whether the degloving injuries are open or closed. As there are no established guidelines or consensus for the management of degloving injuries, we aim to study the incidence, clinical presentation, management and outcome of degloving soft-tissue injuries. Degloving soft-tissue injuries are serious and potentially devastating surgical conditions. Many factors affect outcomes, such as the anatomic location, the force that caused the injury, and the presence of associated injuries. However, early recognition is a crucial step for the favorable outcome.

Figure 2

(a) Large degloving injury of the patients run by a car (b) Injury complicated by extensive necrosis within 72 hours (c) requiring major debridement

Figure 3

Major degloving injury in a patient with severe pelvic injury that was diagnosed late (a) requiring major debridment of skin and subcutaneous tissue

Classification

The various classifications have been described based on 4 patterns of degloving (limited with abrasion/avulsion, non-circumferential, circumferential single plane, and circumferential multiplane degloving).[4] These injuries can occur either in isolation or infrequently in combination . In addition, all degloving soft-tissue injuries are classified as either open or closed. Morel-Lavallée lesions (MLL), is one of the most important type and is a significant soft-tissue injury associated with pelvic trauma (30%) and thigh (20%),[5678] although, it can also be present in other anatomic locations.[9] Such lesions can be related to sports[10] or caused by motor vehicle collisions.

Although, degloving soft-tissue injuries can be present in any part of the body, the lower limb degloving injuries are the most common ones [Figure 1] and if not managed optimally, are associated with high rates of morbidity and potentially mortality [Figure 4].[11] Scalp,[12] upper limb,[3] heel,[13] degloving injuries may cause significant blood loss and hemodynamic instability. In particular, one should keep this in mind with scalp injuries that degloving injuries involving the external genitalia,[14] though uncommon, can be life threatening, with incapacitating and psychologically devastating consequences. Degloving injuries, in children in particular, foot degloving injuries - can be serious and may require advanced complex surgical techniques, if functionality is to be restored.[1516]

Figure 4

A patient with severe degloving injury at the presentation after he had been run by a tire of industrial truck (a) 24 hours later

Diagnosis

Degloving soft-tissue injuries are challenging to diagnose.[39] Clinical assessment of the degloved skin is a weak predictor of the extent of injury. Use of intravenous fluorescein has been proposed as a better assessment method, but may overestimate the line of demarcation between viable and nonviable skin.[17] If arterial inflow is adequate, the soft tissue can be debrided and closed without tension. After incomplete avulsion, skin color, skin temperature, pressure reaction, and bleeding or lack of bleeding should be examined carefully to assess tissue viability.[1819]

Accurate diagnosis of MLL is delayed in up to one third of patients, because of inconsistent clinical presentation and because initial skin bruising can mask the importance of the underlying soft-tissue injuries. In most patients, diagnosis is made from clinical detection of a fluctuant area combined with the findings of appropriate imaging modalities. Serum inflammatory markers sometimes are within the normal range.[5] Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are all useful tools for proper diagnosis, but MRI is the modality of choice for evaluating MLL.

Treatment principles

Treatment of degloving soft-tissue injuries may be complex and requires careful assessment of the extent of the devitalized tissue and the blood supply to the affected tissues. The general treatment principles include preservation of as much tissue as possible, early primary definitive skin cover, good-quality skin cover, early return of function, and the necessity of any secondary procedures.[3]

For finger injuries, the first and best surgical option is always a replantation and revascularization procedure. Often, when the degloved skin is totally removed from the patient's body, it can be put back by replantation. This dual procedure, however, requires great expertise and vast resources. Furthermore, trauma patients often may have other life-threatening injuries that do not allow for a lengthy replantation and revascularization procedures.

For patients with more limited degloving injuries with abrasion and/or avulsion, free tissue transfer procedures can be performed to cover any exposed underlying tendons, bones, and joints. Also, it is recommended to carry on minimal tissue excision (including minimal wound circumcision). Flap reconstruction leads to prompt primary healing. Free tissue transfer techniques include the single-stage microvascular technique. The tissue that is transferred may be either an anterolateral thigh flap,[20] which is a skin flap, or a latissimus dorsi muscle flap,[21] which is covered with a skin graft. Unfortunately, only a very few centers in the world can perform such types of tissue that can be transferred; free tissue transfer procedures have also been limited by the need for expertise in microvascular surgery. Moreover, after reconstruction of a degloved hand or finger, certain secondary procedures may be required (such as scar revision, flap thinning, or syndactyly release).[3]

The avulsed skin has been used as a source of (split- or full-thickness) skin grafts. Surgeons often need to combine defatting of the avulsed skin with fenestration, followed by negative-pressure dressing.[22] If the degloving is extensive, another option is to commit the patient to serial excisions before reconstruction; a theoretical disadvantage is the potential for bone desiccation and nosocomial infection.[23]

For patients with extensive avulsion of the skin including narrow or distal pedicles, with or without involvement of superficial subcutaneous tissue — who do not have damage to deeper tissue, the best treatment is to completely divide the pedicle, defat the skin, and replace the avulsed skin as a full-thickness skin graft. If the wound is too contaminated or too swollen, the avulsed tissue should be cleansed with pulsatile lavage, left open, and addressed at a second exploration. For patients with non-circumferential degloving injuries, tissue excision is always needed. But, with either the application of skin grafts or flap reconstruction, the wound heals by primary intention. For patients with single-plane circumferential degloving injuries, flaps are excised while for patients with circumferential multiplane degloving injuries; a staged reconstruction is suggested.[4] Degloving injuries associated with open fractures should be managed by comprehensive excision of devitalized hard and soft tissue, followed by appropriate skeletal fixation and the application of vascularized soft-tissue cover.[4]

Management of specific anatomical injuries

Lower-limb injuries

The management of lower-limb degloving injuries can be complex and quite involved. In recent years, use of a vacuum-assisted closure (VAC) device to prepare the wound bed for grafting has become standard practice.[222324] Occasionally, lower-limb degloving injuries require cryopreserved split-thickness skin grafts procured from degloved flaps, artificial dermal replacement, or VAC therapy. Some authors have reported using a ring fixator to manage lower-limb degloving injuries; the fixator eventually helps prepare the wound bed for grafting, eases the application of graft tissue, facilitates graft care, and allows for passive mobilization of joints.[25] Yet, the more common technique is radical debridement followed by immediate application of a full-thickness skin graft.

Foot injuries

Management of foot degloving injuries is complex and should involve different specialties. In both children and adults, such injuries can be treated successfully with application of a defatted full-thickness skin graft, followed by conventional dressings. Such treatment is relatively simple, and can provide good functional and cosmetic results. In addition, replacing the degloved skin as a full-thickness graft and securing it with a VAC device can salvage the foot.

Upper-limb injuries

The main options in the management of upper-limb degloving injuries include

Salvaging the degloved segment through revascularization techniques, such as direct arterial anastomosis or arteriovenous shunting, and

Reconstructing the unsalvageable segment with microsurgical or non-microsurgical techniques.[26]

The primary goals include limitation of secondary soft-tissue loss, prevention of infection, serial debridement as needed, temporary joint trans fixation, reconstruction of the microcirculation, dermatofasciotomy in case of compartment syndrome, temporary soft-tissue coverage, systematic conditioning of soft tissues, and secondary soft-tissue reconstruction.[27]

Hand injuries

Hand degloving injuries can be devastating. For a patient with a degloved finger, replantation should be attempted as no other reconstruction procedure can restore the cosmetic and functional characteristics of native finger skin.[28] The various replantation treatment options include replantation surgery with vascular anastomosis; reconstruction with a thumb flap and a portion of one second toe for a dorsal skin flap; reconstruction with the second toe of both feet for a dorsal skin flap; or repair with an abdominal flap.[29]

Other surgeons have replanted the degloved skin using arteriovenous anastomosis of the radial artery (at the wrist) to the cephalic vein (in the degloved skin), in an end-to-side manner; to enhance the survival of the replanted skin, it was de-epithelialized and buried in an abdominal pocket created specifically for this purpose.[30] More recently, a modified abdominal flap (also known as the “compartmented abdominal flap”) has been introduced as a “one-flap solution” for degloving injuries of the hand and fingers.[31] For complete finger degloving injuries, resurfacing the defect with a parallelogram-shaped free flap from the medial arm in a spiral fashion has also been reported.[32] Omental coverage for complex upper-extremity defects is also a good option. The long vascular pedicle and the large amount of pliable, well-vascularized tissue allow the flap to be aggressively contoured to meet the needs of complex 3-dimensional defects. Others have suggested vein arterialization as a valid approach to re-establish the blood supply of a degloved finger — as long as physiologic circulation restoration is not possible and veins in the degloved tissue are not damaged.[3334]

Abdominal wall-degloving injuries

Abdominal wall-degloving injuries have not been reported adequately in the literature, although they represent some of the most serious injuries with potential acute and long-term consequences. Often these injuries are associated with seatbelt injuries, and other intra-abdominal organ injuries, such as mesenteric or intestines (large or small bowel) or solid organ injuries. The treatment is not straightforward by any means and often requires multiple surgeries and complex abdominal wall reconstruction using various meshes, including biologic mesh in the face of infections and loss of abdominal domain.

Management of MLL is complex and may be operative and nonoperative. Surgical treatment includes evacuation of hematomas and necrotic tissue debridement, percutaneous aspiration and compression bandaging, debridement and vacuum dressing, the Ronceray surgical method and other forms. The Ronceray surgical method uses aponeurotic fenestrations to allow active internal drainage and resorption by adjacent muscle fibers.[35] Others use quilting sutures for the management of seroma formation, especially after abdominoplasty and with lesions resistant to conservative measures.[36]

Surgery involves evacuation of the hemolymphatic collection with excision of the pseudo capsule and debridement of necrotic tissue. The wound may be left open, with or without VAC dressing, or it can be closed primarily, with or without a drain. In our practice, if wound closed, large drain (19 Fr) is left in. The use of synthetic glue to close the dead space intraoperatively has been advocated by some authors.[3738] We believe that early percutaneous drainage with debridement, irrigation, and suction drainage appears to be safe and effective for patients with MLL, as has been suggested already.[7] The use of percutaneous drainage needs to be followed with compressive bandages and use of a pressure garment. All complicated MLL require thorough early debridement, either before or during pelvic or acetabular surgery. The wound should be left open; repeated surgical debridement of the injured tissue must be performed, as needed, especially if infection has settled in.[9] For patients with delayed contour deformity caused by liposuction, open surgery is required.[6] If conservative management is pursued for patients with MLL, surgeons must be careful (while removing subcutaneous hematomas and dead fat, performing proper drainage, and applying pressure dressings) and needs to continue to monitor patients carefully to avoid missing dead muscles or the presence of crush syndrome.[39] MLL of the knee can be managed successfully with compression wraps, cryotherapy, aspiration, and active motion exercises.[40]

Scalp injuries

Many techniques are used to treat patients with scalp-degloving injuries.[12] Most of the time, however, enough tissue can be mobilized to close the defect primarily. These defects should be repaired in the operating room, with good lighting under optimal circumstances. Appropriate draining and proper dressing are both crucial.

Study limitations

Our review has a number of limitations, main one being that we did not study non-English studies. Furthermore, our study was not designed to create guidelines or protocols as to how to manage these injuries.

SUMMARY

Degloving soft-tissue injuries are serious and potentially devastating. They require early recognition and early treatment. In the management of closed injuries in particular, a high index of suspicion remains crucial. A multidisciplinary approach is usually needed. Early reconstruction and effective rehabilitation are also essential to care for such patients. There is a need for multi-disciplinary and multi-institutional studies.