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Morel-Lavallee Lesion

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Morel-Lavallee Lesion, Morel Lavallee Lesion

  • Definitions
  1. Morel-Lavallee Lesion
    1. Closed, soft-tissue degloving injury results from high energy Trauma (esp. shearing forces)
    2. Results in hemolymphatic fluid collection between subcutaneous tissue and fascia
    3. Most commonly affects the thigh, hip and Pelvis
  • Background
  1. First described by French physician, Morel-Lavallee in 1863
  • Precautions
  1. Delayed presentation is common (one third of cases)
  2. Consider in high mechanism Trauma, especially Fractures of the hip, Pelvis and lower extremity
  • Pathophysiology
  1. Stage 1: Hypodermis (Epidermis/Dermis/subcutaneous fat) separates from the underlying deep fascia influenced by shearing forces
  2. Stage 2: Disrupts vessels and Lymphatics which leak into the space above the fascial plane
  3. Stage 3: Creates a cavity filled with hemolymphatic fluid (blood, serous fluid, necrotic fat) between subcutaneous and fascial layers
  4. Stage 4: Pseudocapsule forms as a result of chronic inflammation (if untreated)
  • Causes
  1. High Velocity, Multisystem Trauma (e.g. MVA, Crush Injury, Blunt Trauma)
    1. Pelvis Fractures
    2. Acetabular Fractures (MLL in 8% of cases)
    3. Proximal Femur Fractures
  2. Sport Injury (e.g. football)
    1. Direct impact to region (e.g. knee)
    2. Road Rash (e.g. Bicycle accidents)
  3. Abdominoplasty
  4. Liposuction
  • Signs
  • Distribution
  1. Greater trochanter Region or Hip (30% of cases)
  2. Thigh (20% of cases)
  3. Pelvis (18% of cases)
  4. Knee (15% of cases)
  5. Gluteal Region (6%)
  6. Lumbosacral Spine (3%)
  7. Abdominal Wall (1%)
  8. Calf and lower leg (1%)
  • Signs
  • Characteristics
  1. Localized swelling, Ecchymosis and pain in region of Trauma
  2. Region may be fluctuant and compressible, and skin may be hypermobile over the affected area
  3. Decreased Sensation in the affected region may occur
  • Imaging
  1. Ultrasound
    1. Hypoechoic fluid collection overlying Muscle and fascial layer
    2. Fluid is compressible, with possible internal echoes of fat globules
    3. No internal flow with doppler
  2. CT of affected region
  3. MRI of affected region
    1. Preferred definitive study
    2. Mellado and Bencardino Classification defines 6 types (e.g. seroma, Type 2 subacute Hematoma...)
      1. However, classification system correlates poorly with management and prognosis
  • Management
  1. Consult orthopedic surgery early in course
  2. Various management options depending on multiple factors
    1. Conservative Management with compressive therapy (small lesions)
    2. Percutaneous serial aspiration or percutaneous drain (small lesions <50 ml)
    3. Sclerodesis (lesions <400 ml)
      1. Start with aspiration of fluid collection
      2. Inject sclerosing agent (e.g. Doxycycline)
      3. Aspirate sclerosing agent
    4. Early surgical Debridement
      1. Necrosis of overlying skin
      2. Large fluid collection refractory to aspiration
  • Complications
  1. Skin Necrosis
    1. Exposes underlying tissues
  2. Infection
    1. Lesions are colonized in 46% of cases
    2. Increases risk of perioperative infection (esp. orthopedic procedures)
  3. Pseudocyst
  4. Poor Cosmetic result
  • References
  1. Long and Carlson in Swadron (2023) EM:Rap 23(4): 5-7
  2. Morrin and Copeli (2023) Crit Dec Emerg Med 37(9): 20-1
  3. Nair (2014) Indian J Radiol Imaging 24(3):288-90 +PMID: 25114393 [PubMed]
  4. Scolaro (2016) J Am Acad Orthop Surg 24(10):667-72 +PMID: 27579812 [PubMed]