Morel-Lavallée Lesion in the Sacrococcygeal Area with Associated Coccygeal Fracture.

A Morel-Lavallée lesion is a posttraumatic, closed internal degloving injury caused by shearing force abruptly separating the skin and superficial fascia from the deep fascia and creating a potential space. Blood, lymphatic fluid, and debris collect and fill the space. The most commonly affected sites are the thigh, knee, hip, and pelvic area, but the lesion can occur anywhere in the body.