Morel-Lavallée lesion of the anterior leg: a rare anatomical presentation

A Morel-Lavallée lesion (MLL) is a rare injury caused by blunt force trauma causing separation of subcutaneous tissue from the deep fascia. It is frequently seen in orthopaedic cases involving fractures of the hip or pelvis but is rare in the lower leg. The rarity of this condition often leads to misdiagnosis. A 66-year-old man presented to the emergency department after a 300-pound safe sheered across his left anterolateral leg causing skin avulsion, tenderness, swelling, ecchymosis, and erythema. The patient was treated for suspected cellulitis with oral antibiotics, but the lesion evolved into a necrotic eschar necessitating surgical intervention. In hindsight, MLL is a more appropriate diagnosis based on injury mechanism, disease progression and intraoperative findings. A history of shearing trauma with diffuse ecchymosis and erythema should prompt consideration of MLL. Due to rampant misdiagnosis, this case aims to increase awareness, as early diagnosis of MLL will improve patient outcomes.