|Year : 2015 | Volume
| Issue : 6 | Page : 801-803
Amit Kharat1, Dhaval K Thakkar1, Mansi N Jantre1, Amarjit Singh1, Harshil J Vora2
1 Department of Radio-Diagnosis, Dr. D. Y. Patil Medical College and Hospital and Research Centre, Pimpri, Pune, Maharashtra, India
2 Department of Orthopedics, Bharati Vidyapeeth Deemed University, Pune, Maharashtra, India
|Date of Web Publication||19-Nov-2015|
Dhaval K Thakkar
403, Alaknanda, Neelkanth Valley, Ghatkopar (East) Mumbai - 400 077, Maharashtra
Source of Support: None, Conflict of Interest: None
Morel-Lavallée lesion is a degloving injury occurring at the interface of the subcutaneous fat and the underlying fascia. The lesion usually results from shearing forces due to trauma separating the skin and subcutaneous tissue. We report here a case of a patient diagnosed with Morel-Lavallée lesion in the hip region.
Keywords: Degloving injury, Morel-Lavallée lesion, Ultrasound, Trauma, Hip
|How to cite this article:|
Kharat A, Thakkar DK, Jantre MN, Singh A, Vora HJ. Morel-Lavallée lesion. Med J DY Patil Univ 2015;8:801-3
| Introduction|| |
Morel-Lavallée lesion was first described by in 1863 by the French Physician Maurice Morel-Lavallée.  It is a lesion located in the deep subcutaneous tissue and composed of blood, lymph or fat as its contents. The lesions occur due to trauma. It was first described at the external aspect of the thigh. However over a period of years, it has been recognized in other anatomic regions which include knee, lumbar region and the scapula. 
They represent a traumatic separation that is primarily caused due to avulsion of the skin from the underlying fascia. Deforming forces of pressure further result in a closed soft tissue degloving injury, in which the skin and subcutaneous tissue are separated from the underlying fascia, are disrupting the perforating vessels. Cavity formation may occur due to rupture of small perforating vessels that may be filled with blood, lymph and fat foci. , This can potentially lead to bacterial colonization and infection.
Morel-Lavallée lesions may occur in patients with pelvic fractures or blunt trauma. Most commonly, lesions are seen in the proximal thigh and trochanteric region. 
The development of granulation tissue may occur, and it may organize into a pseudo capsule, leading to the persistence of collections.  The lesion may remain asymptomatic in a few cases. In some cases the patient may not give a history of antecedent trauma. 
| Case Report|| |
A 29-year-old male patient came with the complaints of pain and swelling around right hip since 2 months. The pain was dull aching in character and aggravated on movements. A history of trauma to the hip due to fall was present and the patient developed these complains a few weeks after trauma and the swelling gradually increased in size.
A high resolution ultrasonography (US) of the region of interest using a 7-11 MHz transducer revealed a hypo echoicfusiform collection along the lateral aspect of the right hip. Few fine moving echoes are noted. No evidence of definable wall. The lesion is compressible. Gradual pressure of the probe lead to dispersion of the fluid and the lesion was compressible. No abnormal vascularity was noted. No obvious artifacts due to foreign body or air are noted. The underlying muscle and bone is normal. The lesion may show few hyperechoic foci arising from traumatized fat. The underlying muscle and bone is normal. The lesion may show few hyperechoic foci arising from traumatized fat [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5] and [Figure 6].
|Figure 1: Reveals a cystic lesion in the subcutaneous plane with smooth tapering of the upper end|
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|Figure 2: Reveals a cystic lesion in the subcutaneous plane with smooth tapering of the lower end|
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|Figure 3: Cystic lesion in the upper thigh along the lateral aspect without compression. Fine echoes and debris are noted within it|
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|Figure 4: Cystic lesion in the upper thigh along the lateral aspect with compression|
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|Figure 5: It demonstrates the cystic lesion in the subcutaneous plane with an echogenic fat globule within it|
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| Discussion|| |
The other synonyms for these lesions is Morel-Lavallée hematoma, Morel-Lavallée extravasation,
pseudolipoma, pseudocyst, ancient hematoma, organizing
Closed degloving injuries have been found adjacent to bony prominences and are been described adjacent to greater trochanter, flank, buttock, lumbar spine, scapula and knee. ,,, These are due to direct trauma that result in separation of skin and subcutaneous tissues from the underlying fascia.
Morel-Lavallée lesions may often be missed during an initial investigation and may present weeks to months after trauma. It is essential for the radiologist to know the characteristics of acute and chronic lesions on imaging.
Sonographically, Morel-Lavallée lesions appear hypoechoic and well defined. However, their appearance can vary depending on the contents like blood and fat and chronicity of the lesion. , Usually, these lesions are long, and extend craniocaudally over >10 cm. Extended field of view can be used to define the exact extent of the lesion.
Though magnetic resonance imaging (MRI) is the preferred modality for imaging in the evaluation of Morel-Lavallée lesions. The lesions can be mapped and diagnosed easily on ultrasound. Ultrasound can be used to screen the patients, aid planning of therapeutic treatmentoptions and for subsequent follow-up. It can also be used to guide aspirations. Ultrasound is also the modality of choice to determine the capsule.
On MRI the lesions appear homogeneously hypointense on T1-weighted sequences and hyperintense on T2-weighted sequences. The lesions may also appear bright on both T1-weighted and T2-weighted sequences, which may reflect a high internal concentration of methemoglobin, which is a product of hemoglobin degradation. 
Plain radiography reveals soft tissue opacity in the region of the lesion; tangential views may be required to demonstrate the swelling. There may be presence of associated fractures.
The differential diagnosis of the Morel-Lavallée lesion includes other posttraumatic injuries, such as fat necrosis or coagulopathy-related hematoma.  Morel-Lavallée lesion should be considered in a patient presenting with joint swelling and pain in the differentials of other posttraumatic lesions.
These lesions can be managed conservatively by using compression. This is best if done early and the lesions are acute and without capsule.  Larger lesion can be drained percutaneously. However presence of capsule increases chances of recurrence to percutaneous aspiration and drainage and surgical debridement may be necessary.  Percutaneous drainage, debridement, irrigation and suction drainage have been successfully used to manage lesions, as shown by Tseng and Tornetta.  Sclerosing agents like talc and doxycycline have been used to obtain adequate sclerodesis after percutaneous drainage. 
Furthermore, US is the modality which can aid treatment planning [Figure 7]. Sonologists should comment on presence or absence of capsule of the lesion which can assist in choosing the treatment. 
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]