Computed tomographic features of Morel-Lavalleé lesions in three cats

Introduction / Purpose:
A closed degloving injury is a soft tissue trauma with abrupt separation of the dermis from the underlying deep fascia. If a closed degloving injury is accompanied by hemolymphatic fluid accumulation in the created space, this is known as a Morel-Lavallée lesion (MLL). MLL has been extensively reported in humans but rarely in animals. If left untreated, MLL can lead to extensive skin inflammation and necrosis. The computed tomography (CT) features of MLL have not been reported in cats.
Methods:
Institutional archives were searched for cats with clinical and CT features of posttraumatic limb swelling.
Results:
Three cases with MLL were identified, all of which affected the pelvic limbs with a gradually developing unilateral (2 cases) or bilateral (1 case) pelvic limb swelling, skin infection and necrosis. In all three cases, the swelling was caused by fluid accumulation between the dermis and pelvic limb muscles. There was also a vertical attenuation MLL fluid gradient in all cases and no to mild contrast enhancement of MLL fluid.
Discussion / Conclusion:
A well-defined, non- to mildly contrast-enhancing fluid accumulation between the skin and muscle layers in the proximity of a traumatic lesion may be a characteristic CT feature of MLL in cats, similarly as reported in humans. This is different from frequently observed CT features of subcutaneous oedema, cellulitis, and hematoma. Increased awareness and early recognition of MLL is important for clinical management decisions and improved patient outcome.