Morel Lavallee lesions in orthopedics


A Morel Lavallee lesion is a post-traumatic soft tissue degloving injury, originally described by French surgeon Victor Auguste Francois Morel-Lavallee in 1863. These lesions result from direct or tangential shearing forces that separate the skin and subcutaneous tissues from the underlying fascia. These shearing forces can disrupt perforating vessels and nerves, creating a potential space that fills with blood, lymph, debris, and fat (necrotic and/or viable). This can also cause abrasions or friction burns.


Why Important?

Delayed diagnosis or delayed treatment can lead to

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Necrosis-of-the-back-and-bilateral-buttocks-black-arrows-seven-days-after  images

" Even if there is no direct injury to skin the hematoma due to pressure or the hemoglobin released has strong affinity to oxygen causes intense hypoxia and ischemia of skin leading to necrosis"


Closed degloving injuries are most commonly found adjacent to osseous protuberances, and have been described along the greater trochanter, flank, buttock, lumbar spine, scapula, and knee.



Natural history of Morel Lavallee lesions

In a setting of high-energy  injury,  the relatively mobile skin and subcutaneous  tissues are  torn away from the  less yielding aponeurotic  fascia by a crushing and shearing  force,resulting  in blood and  lymphatic vessel disruption.Thus,  a potential  space  is  created  that may  fill with blood,  lymph, and necrotic  fat. Based on this process,  the  resultant subcutaneous  fluid collection may  lead  to various  lesions,  such as  seroma,  subacute hematoma, or  chronic organizing hematoma.  As  the effusion evolves, the blood is largely resorbed and replaced  by serosanguinous fluid. The final step in the evolution of MLLs is creation of a peripheral capsule around the lesion as a  result of an anti-inflammatory  reaction, which may account for the permanence of the fluid mass. Although the swelling may continue  to enlarge gradually-possibly caused by  increased osmotic pressure  in  the cyst from  the chronic infammatory process, repeat trauma, bleeding from friable capillaries.



Clinical features of Morel Lavallee lesions

The clinical features of MLL vary depending on the amount of blood and lymphatic fluid collected at the site of injury and on the time elapsed since the injury. A soft fluctuant area with hypermobile skin is a typical finding on physical examination. Bruising,  ecchymosis,  laceration,  and/or contusion may be  found. MLLs may manifest  as  skin necrosis, which has been  reported  to occur as a  result of direct  trauma  to  the cutaneous  layers but may also occur on a delayed basis secondary  to swelling of  the degloved cavity,  resulting  in  ischemia of  the overlying  skin. Although MLLs  are  closed  injuries, previous  reports have documented  their potential  to be  colonized with bacteria. The skin over a MLL remains  intact,  thus, the  infection of  the cyst  is due  to bacterial  translocation from  the central circulation. Local wound sepsis and life-threatening  sepsis  accompanying MLL have been described.


Diagnostic Imaging

Plain radiography may reveal a noncalcified soft tissue mass and associated fractures. The sonographic appearance is nonspecific and variable, with lesions described as anechoic, hypoechoic and hyperechoic. Hyperechoic nodules of internal fat may be seen on ultrasound. CT can show fluid-fluid levels related to sedimentation of the hemolymphatic fluid, varying amounts of internal debris including internal fat lobules, and may show a peripheral capsule.



MRI is the imaging modality of choice in the evaluation of Morel Lavallee lesions. Morel-Lavalee lesions are well defined oval, fusiform, or crescentic and may have tapering margins that fuse with adjacent fascial planes. Morel-Lavallee lesions may show fluid-fluid levels, septations, and variable internal signal intensity dependent on the concentration of hemolymphatic fluid and the acuity of the lesion.  Lesions may have no capsule, a partial capsule, or complete capsule.  Capsules are hypointense on all pulse sequences related to fibrous tissue and/or blood-by-products. Lesions can have no enhancement, peripheral, septal, or internal enhancement.

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Mellado and Bencardino proposed an MRI classification system of Morel Lavallee lesions based on lesion shape, signal and enhancement characteristics, and presence or absence of a capsule.

classification of Morel Levalle lesion



Although various strategies for the treatment of MLL have been reported, including the application of compression bandages, percutaneous aspiration and drainage, open debridement and sclerodhesis, there are no established treatment modalities for patients with MLL. Conservative management such as compression bandage application, NSAID medication, physiotherapy and absolute bed rest are considered the first-line treatment regimen in patients with acute, small lesions without underlying fractures. Of these, the compression bandage can be used to supplement other treatment options.



" Type 1  and 4 lesion Simple aspiration with needle will not suffice if collection >50ml use  closed suction drain "


Percutaneous drainage can be used to manage larger acute lesions that cannot be resolved with a single application of compression bandages. It may also be attempted along with sclerotherapy as a first-line therapy in patients with chronic lesions. Various methods of sclerodhesis, including some that involve the use of alcohol and doxycycline, have been reported.  Sclerotherapy is performed by injection of sclerosant into the dead space; the sclerosant is allowed to remain for a few minutes, followed by percutaneous drainage. Sclerotherapy can be used as a first-line therapy in patients with acute lesions that are refractory to compression bandages and in patients with chronic lesions. In patients with chronic lesions, percutaneous drainage may result in recurrent postoperative hematoma or secondary infection. It is therefore mandatory to combine percutaneous drainage with sclerotherapy.


“Type 2 lesions  Sclerotherapy with Doxycyline 600mg dissolved in 50ml saline and 10ml lignocaine 1% injected into cavity after aspiration and place continuous drainage tube”

There  is no consensus about  the  surgical  indications or the proper  timing of  the surgery. Its recommended early,  thorough debridement because development of a hematoma  in  the zone of  the operation could  reduce  the safety of any early operative intervention by increasing the risk of  infection and compromising  the skin’s vascularity. When the overlying skin and soft tissue has partial- to full-thickness abrasions or areas of skin necrosis, debridement should be performed at a separate operative setting, before formal open  reduction of  the pelvic  ring or acetabular fracture. When the skin and soft tissue envelope are intact, debridement of the degloved area can be performed during the  same procedure as  the open  reduction and  internal fixation. The wound  should be  left open and  repeated surgical debridement undertaken,  allowing  it  to heal by secondary  intention.


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The lesions can be completely evacuated through incisions at  their proximal and distal extents followed by irrigation and suction drainage. Percutaneous fixation of the posterior part of the pelvic ring may undertaken subsequent to  treatment of  the MLL but during  the  same operative setting. Open  fixation of pelvic  fractures and acetabular fractures is deferred until at  least 24 hours after  the drains are removed. Percutaneous procedures for pelvic fixation  in  the same operative setting are usually well tolerated, and open procedures appear to be safe when performed in a delayed fashion.

Various management  techniques have been proposed based on the consensus of treating MLL with open surgery, which  involves evacuating  the hemolymphatic collection by  excising  the pseudocapsule  and debriding necrotic tissue. Several authors advocated  the use of vacuum dressings and wound closed by  secondary  closure  or  split-skin  coverage. Fibrin sealant spray and  resorbable quilting sutures after surgical debridement have been successfully employed  to eliminate any potential space, thereby reducing the chance of recurrence.


" All Type 3 and 5 lesions require operative surgery with excision of capsule and obliteration of cavity with quilting sutures or fibrin sealant" 

"Type 6 lesion require operative management with debridement and secondary healing or delayed grafting"


Management of Overlaying skin

"Never assume wait and watch attitude you should control the wound"



"In cases where the skin is thin and completely devascularized following drainage of hematoma then completely de fat the skin and make fenestrations and place over raw area as full thickness graft and apply negative pressure wound therapy, alternatively harvest split skin graft from flap and graft the wound "



The difficulty in management of Morel-Lavallee lesion is in predicting skin viability. Fluorescein is a fluorescent dye used in flow cytometry, which has been used experimentally to assess tissue viability. It is administered intravenously upon flap elevation, and the fluorescence is subjectively measured with the aid of ultraviolet light approximately 10 to 15 minutes postadministration. Viable skin appears bright yellowish green; flaps that are blue and nonfluorescent are not viable. Skin with spotty areas of fluorescence lies somewhere in between. In one study, the fluorescein test was extremely reliable even when it contradicted traditional clinical signs of viability such as capillary refill and flap color. Fluorescein is relatively safe; side effects include nausea and vomiting. The manufacturers have found no reports of death related to its use. Despite the study's success, fluorescein has not been widely studied for this application. With further investigation, this may be a valuable asset to the physician faced with assessing skin viability of a Morel-Lavallee lesion.





" Use a cost effective and simple technique of fluorescent dye injection and observation of skin flap with Woods lamp intraopratively any Areas of nonfluorescence <4 cm2 typically survive and >4cm2 may be debrided"



Have a high index of suspicions in cases which present with swelling or eccymosis and abrasion of skin. MRI is the ideal diagnostic modality. Always drain the underlying hematoma. Early management of skin can help in early bone intervention and early recovery.




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