Morel-Lavallée lesion

Case contributed by Dr Yasser Asiri


Knee trauma with swelling and tenderness medially

Patient Data

Age: 30 years
Gender: Male

Subcutaneous soft tissue edema in the medial aspect of the knee is noted. Alignment is maintained. Joint space and outline are maintained. No acute fracture or dislocation. No joint effusion noted. 


There is an oblique/ horizontal high signal intensity seen in the of the posterior horn of the medial meniscus in keeping with oblique tear. Mild intermediate signal intensity in the lateral meniscus suggestive of mucoid degeneration or related to contusion. The medial collateral ligament is intact.

There is subcutaneous laminar collection noted in anteromedial aspect of the knee separating fascia from the subcutaneous fat with peripheral medial fat lobules and internal septations.  It shows high signal intensity on T2 weighted images and low signal intensity on T1 weighted images. The imaging appearance is compatible with type I Morel-Lavallée lesion.

Case Discussion

Subcutaneous fluid collection located along the fascial planes in the setting of trauma would raise the possibility of degloving injury. MRI imaging is helpful to diagnose these lesions due to their characteristic location and imaging appearance and also help to rule out other trauma-related injuries. 

This patient sustained trauma while playing football and presented with pain and hematoma in the medial aspect of the knee which clinically mistaken for medial collateral ligament injury. Mellado-Bencardino classification is used to differentiate between the types of Morel-Lavallée lesions based on the signal intensity and other features. 

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Case information

rID: 65276
Published: 11th Jan 2019
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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