Morel-Lavallée injury.
Diagnostics, treatment and rehabilitation.
Morel-Lavallée was first described by a French physician, you guessed it, Maurice Morel-Lavallée in 1863. He described it himself as a closed traumatic soft tissue injury, also known as a "degloving injury." It describes a situation in which the skin and underlying tissue become detached from the deeper structures by a powerful moment, similar to peeling off a glove. This injury is characterized by loosening of the deep fascia of the skin and the superficial layer of skin. In most cases, it involves a shearing force. This injury creates a space in which fluid, usually a mixture of blood and lymph fluid, accumulates and can cause symptoms.
Origin of the Morel Lavallee
This injury is primarily caused by high-energy trauma, most commonly seen on or around the femur. However, it can also occur after a simple contusion. In addition, it is also described that this injury can also occur in some contact sports, such as soccer. The most common cause in this context is a shearing force, most often involving the knee.
In the acute phase, immediately after the injury, Morel Lavallee manifests as a smooth mobile swelling at the site of injury. In a later phase, it may present as a cystic or encapsulated accumulation of fluid. Sometimes the Morel Lavallee injury often accompanies other injuries.
For this reason, other injuries may derive from the Morel-Lavallée injury. When the diagnosis of this injury is delayed or missed, it can lead to increasing difficulties in treatment and long-term consequences. When the injury is not treated correctly, it can progress to an injury that is more chronic in nature. This involves an inflammatory reaction that leads to the formation of a fibrous capsule, which presents as a cyst. For this reason, prompt and effective management of the Morel-Lavallée injury is important. This chronic variant is often referred to in the literature by different terms, such as Morel-Lavallée seroma, post-traumatic soft tissue cyst, post-traumatic extravasation, Morel-Lavallée effusion or a chronic expanding hematoma.
Etiology of Morel-Lavallee
Etiology is a medical term, the word comes from the Greek terms aitia (cause) and logos (study or science). In the context of medicine, etiology seeks to explain why and how a particular condition arises.
The most common cause of a Morel-Lavallée injury is a fall or moment of contact where the forces are large enough to cause actual damage. In the medical world, we also call this high-energy trauma. It occurs most often in the region of the greater trochanter, the bone region on the side of the hip. This is because this region is somewhat more vulnerable to this type of injury. It is a relatively large area with a lot of skin mobility. This area, along with the buttock region, is well supplied with blood. This is not to say that it cannot occur in other areas. We also see that it can occur in places such as the lower leg, especially with direct impact during sports such as soccer. It can also occur very rarely after surgeries such as liposuction or abdominoplasty. Morel-Lavallee can occur in the following areas of our body:
Hip region (30.4%), Thigh (20.1%), Pelvis (18.6%), Knee (15.7%), Butt region (6.4%), Other regions such as lower back, abdomen and lower leg region (<5%).(1)
Epidemiology
The Morel-Lavallée injury often occurs in combination with other serious injuries, such as fractures of the upper leg (femur), pelvis and hip socket (acetabulum). Large-scale studies show that this injury is twice as common in men as in women(2). This is probably explained by men's greater exposure to severe trauma, caused by a mix of risk-taking behaviors, hazardous occupations and social expectations.So women seem to be slightly better at hazard assessment after all, but let's save that topic for another article. Because these injuries often go unrecognized or are recognized too late, the actual number of cases is probably higher than reported.
Pathophysiology of the Morel-Lavallée lesion
So this injury is caused by a shearing force where the underlying fascial layers and superficial skin layers move relative to each other. This creates a cavity leading to leakage of blood, lymph and a fatty structure. The rate of accumulation depends on the amount of fluid and the number of damaged blood vessels.
The Morel-Lavallée lesion is usually visible within hours to days after the trauma. In one-third of cases, however, presentation may occur months to years later. Of course, the clinical manifestations can be different depending on various factors such as the amount and rate of accumulation of blood and other fluid. But also simply consider the person's physique.
In the acute phase, the patient may experience symptoms such as:
- Pain
- Blue discoloration
- A smooth accumulation of fluid on physical examination
- Delayed discoloration of the skin, which can complicate diagnosis.
Prolonged lesions can lead to decreased skin sensitivity resulting in damage to superficial nerves. In more rare cases, secondary infections may develop, such as soft tissue cellulitis or localized abscesses. However, this is not what we often see in physical therapy practice. Because we deal a lot with athletes in physical therapy practice, we are more likely to see a Morel-Lavallée injury seen around the knee, caused by a direct contact moment during sports activities. This type of injury is common in contact sports, such as soccer or rugby, where a collision or fall leads to the typical shearing force that causes the injury.
Morel-Lavallee injury within the physical therapy practice
Ultrasound can be valuable as a tool within physical therapy for confirming smaller Morel-Lavallée lesions. It can map the exact location, size and deformability of the lesion and confirm the suspicion. In more acute lesions (18 months) have a more homogeneous and smooth appearance. Although ultrasound is useful, other serious conditions, such as tumors, cannot always be ruled out. For detailed assessment of larger or complex lesions, MRI is clearly preferred. It provides a more accurate description of the contents, size but also the stage the lesion is in. Acute lesions will have a different picture due to a lot of fluid accumulation, while chronic lesions show a fibrous capsule.
Morel-Lavallee treatment
For small, acute lesions, conservative treatment, such as the use of compression bandages and NSAIDs (nonsteroidal anti-inflammatory drugs), can be effective to reduce swelling and prevent further inflammation. Percutaneous aspiration, often performed under ultrasound guidance, is employed to drain the cavity, but has a higher risk of relapse in larger lesions (>50 ml)(3,4).
For more persistent lesions, a sclerosing agent may be injected into the cavity. This irritates the inner wall of the cavity, causing an inflammatory reaction. This inflammation stimulates the formation of scar tissue, leading to permanent closure of the cavity. This prevents further accumulation of fluid. Agents such as doxycycline or ethanol are used to close the cavity, with a success rate of about 95%(2).
For larger and complex Morel-Lavallée lesions, minimally invasive surgery may be used to shrink the space. In severe cases, open surgery may be necessary, sometimes combined with skin grafts. However, these treatments have little relevance to physical therapy practice because these complex lesions are usually already diagnosed and treated elsewhere.
Summary, insight and future prospects
The Morel-Lavallée injury is a complex injury often caused by a severe trauma event and sometimes accompanied by underlying injuries. Early recognition is essential to prevent complications such as infection. The picture ranges from soeple swelling and bruising to chronic hardening. Here, imaging, such as MRI, plays an important role in the diagnosis and classification of the injury.
Treatment depends on the size, location, stage and severity of the injury. Small acute injuries can sometimes be treated conservatively with compression bandages, while larger or chronic injuries often require more invasive interventions, such as percutaneous aspiration, sclerotherapy or surgery. Minimally invasive techniques show promising results because of their efficacy and low complication risk.
In physical therapy practice, alertness to complex soft tissue injuries, such as the Morel-Lavallée lesion, is crucial. Symptoms such as swelling and pain may resemble other conditions, such as bursitis or other pathologies. Therefore, careful evaluation and differential diagnosis are important. Ultrasound can assist physical therapists in assessing the location and severity of an injury and can help rule out alternative diagnoses. If necessary, ultrasound can also play a role in referring to a specialist, such as an orthopedic surgeon or radiologist.
Future prospects lie in improving diagnosis and treatment through large-scale randomized studies. These studies are needed to better understand the effectiveness of different treatment options and develop standards. Moreover, multidisciplinary collaboration between orthopedic surgeons, plastic surgeons, rehabilitation specialists and physical therapists can contribute to better prognosis and faster recovery of patients. In this regard, physical therapists play a key role in both early recognition and rehabilitation after treatment.
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