This MRI study shows a focal well defined lentiform shaped subcutaneous collection on medial aspect of knee joint superficial to the superficial fascia. Collection is clear, hypo intense on T1-weighted images without any septations or loculations. No obvious high signal intensity methaemoglobin staining on T1-weighted images to suggest any frank haematoma.
Morel-Lavallée lesion
These are focal well defined lentiform shaped subcutaneous serous collections commonly encountered during MRI knee joint in the setting of severe trauma. However these lesions are typically described in thigh as a well defined collection overlying the greater trochanter of the femur and the tensor facia lata.
These are actually localized haemolymphatic collections secondary to closed degloving injuries, where the skin and subcutaneous fatty tissue abruptly separate from the underlying fascia owing to trauma. The potential space thus created superficial to the superficial fascia is filled by serous fluid, some times frank blood. Similar collection secondary to similar biomechanical forces are described in lumbar region and over the scapula as well.
The accumulated collection usually needs nothing to be done, resolves spontaneously. However may persist longer if it gets organized and encapsulated. The conservative management is with compression bandage. Surgical drainage may be sufficient for larger collection. However, the capsule may need to be resected to prevent recurrence if it is long standing and encapsulated collection with thick organized wall.
Bonilla-Yoon, I, Masih, S, Patel, DB, et al. The Morel-Lavallée lesion: pathophysiology, clinical presentation, imaging features, and treatment options. Emerg Radiol. 2014; 21: 35–43.
ReplyDeleteThe location of Morel-Lavallee lesion is supposed to be just superficial to the deep fascia.
There is a confusion in the literature itself.