Morel-Lavallee lesion: An uncommon internal degloving injury in trauma patients

Introduction: Morel-Lavallee (ML) lesion is an uncommon closed internal degloving soft tissue injury seen in patients with blunt trauma. As it often takes days to weeks after trauma to develop, it may go undiagnosed and can be missed in up to 44% of the cases.Methodology: A comprehensive literature search was performed using various databases till August 2022. Twenty-eight articles related to the pathophysiology, clinical presentation, diagnosis, treatment or complications of ML lesions were included and summarized in this review.Discussion: Shearing forces lead to separation of the skin and subcutaneous tissues from the fascia superficial to underlying muscles, and collection of fluid in this space leads to development of a palpable fluctuant swelling. The most common etiologies were motor vehicle crashes, falls and contact sports. It usually forms adjacent to a bony protuberance. Common symptoms include pain and swelling over the injured area, either presenting acutely after the trauma, or developing few days to weeks after the injury. It is often misdiagnosed as muscle contusion or hematoma, abscess or neoplasm. Use of bedside ultrasound and computed tomography (CT) can aid in its identification, but magnetic resonance imaging (MRI) is the imaging modality of choice. Depending on the size and severity of the lesion, as well as presence or absence of a capsule, definitive management can be conservative or surgical.Conclusion: 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.