UMEM Educational Pearls

Category: Trauma

Title: Morel-Lavallée Lessions

Keywords: soft tissue injury, trauma, (PubMed Search)

Posted: 12/10/2023 by Robert Flint, MD (Updated: 4/13/2024)
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Here are three good resources to learn about a soft tissue injury seen in high velocity blunt trauma patients called Morel-Lavallee lessions.

“Morel Lavallee lesions are soft tissue injuries seen in high-velocity trauma and are usually associated with underlying fractures of the pelvis, acetabulum, or proximal femur. Often these injuries are not immediately diagnosed due to the distracting concomitant bony injuries. However, identification of such injuries is important as they may pose as an independent risk factor for surgical site infection. The clinical findings include soft tissue swelling, bruise/ ecchymosis, fluctuance, and compressibility in the swelling. The diagnosis is usually established on physical examination, however, radiological investigations including ultrasonography and CT might help. The management options include nonoperative treatment, percutaneous aspiration, and open debridement.” 1

“Morel-Lavallée lesions are often the result of skin and subcutaneous tissue quickly tearing away from the underlying fascia. This allows a range of fluids to fill the space in the form of hemolymphatic masses. The two most common sites are the prepatellar plate of the knee and the lateral fascia of the hip.” 2

“ML lesion is often undiagnosed during initial presentation of a trauma patient, and emergency physicians and trauma surgeons should be aware of the possibility of occurrence of this injury. MRI is the imaging modality of choice, and the presence or absence of a capsule is an important imaging finding that guides appropriate therapy. Early diagnosis and management will help prevent long-term morbidity and complications in these patients.”3