Morel-Lavallée-Like Periosteal Degloving Lesion of the Tibia Following Trauma: A Novel Observation.

Morel-Lavallée lesion (MLL) is a closed degloving injury resulting from the separation of the subcutaneous tissue from the underlying deep fascia due to shearing forces. It most commonly occurs around the pelvis, hip, and thigh. We describe an unusual post-traumatic lesion resembling an MLL but occurring at the periosteal interface of the tibia. A 49-year-old man presented with a localized swelling over the upper anterior aspect of the right leg that developed two months after a blunt injury sustained while kick-starting a motorcycle. Physical examination revealed a firm, mildly tender swelling over the proximal tibia. Ultrasonography demonstrated a well-defined subperiosteal anechoic collection with minimal heterogeneous echogenic contents, consistent with an organized chronic subperiosteal hematoma. Unlike a conventional MLL, the lesion was confined to the plane between the tibial periosteum and the overlying fascial-soft tissue envelope, without intramuscular extension or internal vascularity. Plain radiographs showed no osseous involvement. Ultrasound-guided aspiration confirmed the diagnosis of chronic hematoma. This case highlights a previously undescribed Morel-Lavallée-like periosteal degloving lesion of the tibia resulting in a chronic subperiosteal hematoma. Recognition of this atypical injury pattern and its characteristic ultrasonographic appearance may facilitate the accurate diagnosis of chronic post-traumatic tibial swellings and help avoid unnecessary investigations.