MOREL-LAVALLEE LESION (MLL): case report and literature review on diagnosis and management of post-traumatic MLL in patients with polytrauma

Abstract

Morel-Lavallee lesion has become an eponym since Maurice Morel-Lavallee described the first closed degloving injury in 1853. In present days, Morel-Lavallee lesion is still a rare condition resulting from blunt shearing of soft tissues due to trauma that separates the hypodermis from underlying fascia. The cavity that is created between the separated skin with subcutaneous tissue and fascia becomes filled with blood due to injury to perforating arteries as well as necrotic tissues. Although the MLL is often seen in traumatic injuries to lower extremities, mostly secondary to MVCs, however, they are also seen on trunk and buttocks.

The closed cavity formed between subcutaneous tissue and fascia may remain unrecognized for some time. However, often the lesion is easily identified on CT or MRI as well as US images taken as part of complex work up of trauma patient or for soft tissue swelling in patient with history of blunt trauma. With time the closed cavity becomes organized secondary to inflammatory reaction and subsequent development of granulation tissue and the fibrous pseudocapsule. And as the pseudocapsule is formed around the contents of the MLL, patients often have no specific clinical symptoms, except for swelling of the site. The contents of the MLL thus may remain unrecognized for many days or even months.