What is the initial management for a Morel-Lavallee lesion?

Initial Management of Morel-Lavallée Lesions

Early percutaneous drainage with débridement, irrigation, and suction drainage is the recommended initial management for Morel-Lavallée lesions to prevent complications such as recurrence, infection, and chronic pain. 1, 2, 3

What is a Morel-Lavallée Lesion?

A Morel-Lavallée lesion (MLL) is a closed degloving injury that occurs when trauma delivers a shearing force to soft tissue, causing separation between the subcutaneous tissue and underlying fascia. This creates a potential space that fills with blood, lymph, and necrotic fat.

• Most commonly affects the greater trochanter, thigh, and pelvis
• Results from high-velocity trauma (often motor vehicle collisions)
• Creates a hematoma/seroma that has high risk of bacterial colonization and recurrence

Diagnosis

• Clinical presentation: fluctuant swelling, bruising, decreased cutaneous sensation
• Imaging:
  • Ultrasound: hypoechoic or anechoic collection with potential internal septations
  • MRI: fluid collection between subcutaneous tissue and fascia (gold standard for evaluation)
  • CT scan with IV contrast: helpful when associated with pelvic fractures 1

Initial Management Algorithm

1. Assessment and Stabilization

   • Evaluate vital signs and hemodynamic status
   • Assess for associated injuries, particularly pelvic fractures
   • Apply pelvic binder if unstable pelvic fracture is suspected 1

2. Lesion Evaluation

   • Determine size, location, and chronicity of the lesion
   • Assess for active bleeding and contamination
   • Key Decision Point: Measure fluid volume if aspiration is performed

3. Treatment Based on Fluid Volume

   • If aspiration yields >50 mL of fluid: Proceed directly to operative management

     • This is a critical threshold - lesions with >50 mL have 83% recurrence rate with aspiration alone 2

   • If aspiration yields <50 mL of fluid: Consider non-operative management with compression and observation 2

4. Operative Management Technique

   • Percutaneous drainage through two 2-cm incisions (one distal, one superior/posterior)
   • Débridement of injured fatty tissue using a plastic brush
   • Thorough irrigation with pulsed lavage
   • Placement of medium Hemovac drain until drainage <30 mL/24 hours 3
   • Consider wound vacuum-assisted closure for larger lesions 2

Special Considerations

• Associated Fractures: If pelvic or acetabular fracture fixation is needed:

  • Percutaneous fixation can be performed during the same operative setting
  • Open fixation should be delayed until at least 24 hours after drain removal 3

• Chronic Lesions: More likely to require formal operative debridement with potential need for split-thickness skin grafting 2, 4

• Complications to Monitor:

  • Recurrence (56% with aspiration alone vs. 15% with operative management)
  • Infection
  • Chronic pain
  • Skin necrosis 2, 4

Follow-up Care

• Regular wound assessment
• Monitor for signs of infection or recurrence
• Continue compression therapy during healing phase
• Evaluate for proper healing and functional recovery 1

By following this algorithm with early intervention focused on drainage and debridement, particularly for lesions with >50 mL of fluid, clinicians can significantly reduce the risk of recurrence and complications associated with Morel-Lavallée lesions.