Definition[edit | edit source]
A Morel-Lavallée lesion (MLL) was first described in 1853 . It is a closed soft-tissue degloving injury that usually occurs after blunt trauma. In recent literature, it can also be referred to as Morel-Lavallée seroma or effusion, post-traumatic soft tissue cysts or post-traumatic extravasations.
Epidemiology and aetiology[edit | edit source]
These injuries occur due to blunt trauma after:
Pathophysiology[edit | edit source]
MLL occurs due to shearing forces which separate the skin and subcutaneous tissue from the deep fascia, causing a potential space. Damage to the lymphatic and blood vessels leads to an accumulation of blood and lymph and necrotic fat in the potential space, causing a haematoma or seroma. Blood will start to be reabsorbed over time leaving a serosanguinous fluid surrounded by a haemosiderin layer. Inflammation is then induced by the haemosiderin layer leading to a fibrous capsule. This fibrous capsule prevents more fluid reabsorption, initiating a chronic MLL.
MLL are often associated with pelvic or acetabular fractures but can also occur without a fracture.
Secondary risk factors for an MLL include female gender and BMI of over 25.
Clinical Presentation[edit | edit source]
MLL occurs most commonly over the greater trochanter (>60% of cases) , proximal femur, buttock, knee and in rare cases, the lumbar region. It can also occur at the scapula. Delayed presentation (months or years) can occur in up to ⅓ of patients. The most common signs and symptoms include:
- Compressible, fluctuant swollen area. The fluctuant swelling is an essential clinical characteristic.
- Cutaneous anaesthesia or hypothesia may be present
- Ecchymosis may be present
- Abrasions may be present
- Secondary dermal changes e.g. discolouration, frank necrosis, drying/cracking
Complications[edit | edit source]
The necrotic tissue associated with the MLL is particularly susceptible to infection and if infection occurs, it can lead to
Classification[edit | edit source]
Mellado and Bencardino proposed a MRI classification and identified 6 types of MLL based on the lesion chronicity, appearance on MRI and tissue composition . The 6 types include the following:
Type I to III are the most common types with Type I being acute, type II, sub-acute and III, chronic.
Diagnosis and Imaging[edit | edit source]
Diagnosis of MLL should be based on the patient’s history, the physical examination and imaging.
Ultrasound, MRI and CT scan can be used to diagnose MLL. On ultrasound, the fluid mass is located anterior to the muscle but posterior to the hypodermis. MRIs are particularly important in the diagnosis of MLL  and help with differential diagnosis.
MLLs are often missed (up to one third of cases) and untreated lesions can lead to complications such as infection and chronic lesions. Early diagnosis is very important to prevent infection and development of the capsule (chronic lesion).
Differential diagnosis[edit | edit source]
- Soft tissue malignancy 
Physiotherapy management[edit | edit source]
Although physiotherapy cannot directly treat the MLL, it can help improve functional activities and reduce pain. There is no specific physiotherapy protocol, as the physiotherapy management will depend on what the patient requires e.g. range-of-motion improvement, gait re-education or strengthening. Physiotherapy management depends on the severity of the lesion, the medical/surgical management and the amount of bed rest the patient had. A case study (2022) of a patient with a thigh MLL, found that physiotherapy significantly improved joint range-of-motion, strength, cardiovascular/pulmonary function and functional independence. Another study (2021) found that physiotherapy was essential to get the best functional outcomes after surgery or conservative management.
Medical management[edit | edit source]
Compression bandaging can be done in acute and chronic cases , with or without sclerotherapy. Effective bandaging however not always possible in certain areas e.g. greater trochanter.
Existing evidence suggests that surgical treatment results is shorter healing time compared to compression bandaging alone. While some MLL can resolve spontaneously, others have symptoms that can persist for decades and affect quality of life in untreated cases.
Surgical management[edit | edit source]
Surgical management is indicated if conservative management fails; where an untreated chronic lesion has developed a fibrous capsule due to ongoing inflammation; where the diagnosis is unclear or where there is secondary infection. Surgical treatment options include:
- Sclerotherapy alone in lesions with a volume of up to 400ml. Sclerodesis with Doxycycline is most common but other agents such as erythromycin, vancomycin and tetracycline are also used. The majority of these sclerodesis agents cause fibrosis as they induce cell destruction.
- Percutaneous drainage with or without sclerotherapy (acute or chronic)
- Drainage and debridement. Open debridement is done when there is an open fracture.
- Open capsule excision in chronic and large, recurrent cases
References[edit | edit source]
- Diviti S, Gupta N, Hooda K, Sharma K, Lo L. Morel-Lavallee lesions-review of pathophysiology, clinical findings, imaging findings and management. Journal of clinical and diagnostic research: JCDR. 2017 Apr;11(4):TE01.
- Singh R, Rymer B, Youssef B, Lim J. The Morel-Lavallée lesion and its management: a review of the literature. Journal of orthopaedics. 2018 Dec 1;15(4):917-21.
- Zairi F, Wang Z, Shedid D, Boubez G, Sunna T. Lumbar Morel-Lavallée lesion: case report and review of the literature. Orthopaedics & Traumatology: Surgery & Research. 2016 Jun 1;102(4):525-7.
- LaTulip S, Rao RR, Sielaff A, Theyyunni N, Burkhardt J. Ultrasound utility in the diagnosis of a Morel-Lavallée lesion. Case Reports in Emergency Medicine. 2017 Feb 1;2017.
- Depaoli R, Canepari E, Bortolotto C, Ferrozzi G. Morel-Lavallée lesion of the knee in a soccer player. Journal of ultrasound. 2015 Mar;18(1):87-9.
- Mettu R, Surath HV, Chayam HR, Surath A. Chronic Morel-Lavallée lesion: a novel minimally invasive method of treatment. Wounds. 2016 Nov 1;28(11):404-7.
- Christian D, Leland HA, Osias W, Eberlin S, Howell L. Delayed presentation of a chronic Morel-Lavallee lesion. Journal of Radiology Case Reports. 2016 Jul;10(7):30.
- De Coninck T, Vanhoenacker F, Verstraete K. Imaging features of Morel-Lavallée lesions. Journal of the Belgian Society of Radiology. 2017;101(Suppl 2).
- Badjate DM, Jain D, Phansopkar P, Wadhokar OC. A Physical Therapy Rehabilitative Approach in Improving Activities of Daily Living in a Patient With Morel-Lavallée Syndrome: A Case Report. Cureus. 2022 Sep 24;14(9).
- Weiss NA, Johnson JJ, Anderson SB. Morel-lavallee lesion initially diagnosed as quadriceps contusion: ultrasound, MRI, and importance of early intervention. Western Journal of Emergency Medicine. 2015 May;16(3):438.
- Cruz N, Jiménez R. Morel-Lavallée lesion diagnosed 25 years after blunt trauma. International Journal of Surgery Case Reports. 2021 Apr 1;81:105733.
- Cochran GK, Hanna KH. Morel-Lavallee lesion in the upper extremity. Hand. 2017 Jan;12(1):NP10-3.
- Agrawal U, Tiwari V. Morel Lavallee Lesion.
- Dawre S, Lamba S, Gupta S, Gupta AK. The Morel-Lavallee lesion: a review and a proposed algorithmic approach. European Journal of Plastic Surgery. 2012 Jul;35(7):489-94.