A degloving injury is a severe soft tissue wound where a large section of skin and the layer of fat beneath it are forcefully separated from the underlying muscle, fascia, or bone. This trauma, known as avulsion, strips the protective soft tissue layers from the body’s deeper structures, much like a glove being pulled off a hand. Due to the extensive surface area affected and damage to the underlying blood supply, degloving injuries are considered medical emergencies requiring immediate and specialized attention. The severity often leads to significant blood loss and a high risk of tissue death, making rapid assessment and intervention necessary to preserve the affected limb or body part.
The Mechanics of Tissue Separation
Degloving injuries occur when high-energy trauma delivers intense mechanical forces, primarily shearing and avulsion, to the body’s soft tissues. The skin and subcutaneous fat are abruptly pulled apart from the deep, fibrous layer of tissue covering the muscles, called the deep fascia. This separation happens because the skin layers are relatively mobile compared to the deep fascia, which is firmly anchored to the muscle and bone below.
The force causes a tearing action along this natural plane of weakness, creating a large, empty space, or “dead space,” between the layers. As the soft tissues are ripped away, the small blood vessels and lymphatic channels that supply the skin are severed. This disruption immediately compromises the blood flow to the detached skin and fat, leading to tissue death without rapid surgical intervention.
The injury can also damage nerves running through the subcutaneous layer, potentially causing a loss of sensation in the affected skin. This mechanical shearing is a direct result of forces like crush, torsion, or rapid dragging, often encountered in accidents involving machinery or motor vehicles.
Categorizing Degloving Injuries
Degloving injuries are broadly categorized into two main types based on the integrity of the overlying skin. Open Degloving is the more visually apparent and severe form. In this case, the skin and fat layers are completely torn away, either partially remaining as a skin flap or being entirely removed, exposing the underlying muscle, tendons, or bone.
Open injuries most frequently affect the extremities, particularly the legs, but they can occur on the torso or scalp. Because the wound is open, there is an immediate and high risk of contamination and infection. The exposed underlying structures make the diagnosis straightforward, but the full extent of the damage to deep tissues and vasculature requires detailed medical assessment.
The second type is Closed Degloving, also known as a Morel-Lavallée lesion, which is less obvious and often presents a diagnostic challenge. This injury occurs when the skin remains intact but has been internally separated from the deep fascia. The internal “dead space” created by the shearing force rapidly fills with a collection of blood, lymphatic fluid, and liquefied fat, forming a fluid-filled cavity beneath the skin.
Closed degloving lesions commonly occur over bony prominences where the skin is tightly bound, such as the greater trochanter of the hip, the lower spine, and the knee. The injury may appear only as bruising, swelling, and a palpable area of fluid collection. Due to the subtle presentation, closed injuries can sometimes be overlooked, with symptoms only fully developing days or weeks after the initial trauma.
Surgical Repair and Acute Management
The acute management of a degloving injury begins with immediate stabilization of the patient upon hospital arrival, focusing on controlling blood loss and preventing shock. Surgeons must perform a meticulous assessment to determine the viability of the degloved tissue and any associated damage to nerves and blood vessels. Non-viable tissue must be systematically removed in a procedure called debridement, often involving multiple surgeries to ensure all damaged tissue is excised.
For open injuries, the goal is wound coverage and reconstruction, which depends heavily on the extent of the defect. If the degloved skin is determined to be healthy enough, it can be surgically modified by defatting and fenestrating it, then reapplying it as a full-thickness skin graft over the wound bed. This approach provides the best possible tissue match in terms of appearance and texture.
When the defect is too large, or if the underlying bone or tendons are exposed, more complex methods are needed. One option is free flap surgery, which involves transplanting skin, muscle, and blood vessels from a distant, healthy part of the body to the wound site with the blood supply intact, for a more robust coverage. Less severe defects may be covered with a split-thickness skin graft, which uses only the top layers of skin from a donor site.
For closed degloving injuries, initial treatment may involve conservative measures like compression bandaging and fluid aspiration to drain the collection. However, large or persistent Morel-Lavallée lesions often require surgical intervention, such as incision and drainage, to evacuate the fluid and remove the fibrous capsule that can form around the collection. Negative-pressure wound therapy is frequently used after debridement to prepare the wound bed for grafting and to aid in the attachment of the new skin.