Morel-Lavallee Lesion

Morel-Lavallee Lesion

David Ray Velez, MD

Table of Contents

Definition and Pathophysiology
Presentation
Diagnosis and Classification
Treatment

Definition and Pathophysiology

Definition: Closed Degloving Soft Tissue Injury Causing Dermal-Fascial Separation

Pathophysiology

  • Skin and Subcutaneous Tissue are Separated from the Underlying Fascia
  • Shear Injury Causes Disruption of Blood Vessels and Lymphatics
    • Creating a Space for Fluid Collection

4-Stages

  • Stage 1: Shearing Force Causes Dermal-Fascial Separation
  • Stage 2: Fluid is Produced from Injured Blood Vessels and Lymphatics
  • Stage 3: Fluid is Replaced by Serosanguinous Fluid Over Time
  • Stage 4: Local Inflammation Causes a Pseudocapsule Formation

Morel-Lavalle Lesion – Mechanism of Injury 1

Presentation

Presentation

  • Classic Presentation: Enlarging Painful Lesion with Swelling and Fluctuance
  • Ecchymosis with Pain Out-of-Proportion
  • High Risk for Infection – 46% Have Bacterial Colonization
  • High Risk for Skin Necrosis

Up to 33% are Missed on the Initial Examination

Locations

  • Peri-Trochanter Region of Proximal Thigh – Most Common Site
  • Buttock
  • Back
  • Abdomen
  • Flank

Most Common Etiology: Motor Vehicle Crash (MVC)

Morel-Lavallee Lesion – Skin Necrosis on Day #4 2

Diagnosis and Classification

Diagnosis Requires a High Index of Suspicion

Diagnosis – Primarily Based Upon Imaging

  • CT – Most Common
  • MRI (Preferred in Some Literature)
  • May Be Seen on US but Less Common

Classification (Mallado and Bencardino)

  • *Largely Based on MRI Findings
  • Type I: Seroma
  • Type II: Subacute Hematoma
  • Type III: Chronic Organizing Hematoma
  • Type IV: Perifascial Dissection with Closed Fatty Laceration
  • Type V: Perifascial Pseudonodular Lesion
  • Type VI: Infected Lesion

Morel-Lavallee Lesion of Left Hip on MRI 3

Treatment

Primary Treatment: Incision & Drainage

  • Any Pseudocapsule Should be Resected to Decrease the Recurrence Risk
  • Necrotic Skin Requires Debridement and Possibly Skin Grafting

Conservative Management – Generally Preferred if Small (< 50 cc)

  • Compression (ACE Wrap or Compressive Bandages)
  • Percutaneous Drainage/Aspiration

References

  1. De Coninck T, Vanhoenacker F, Verstraete K. Imaging Features of Morel-Lavallée Lesions. J Belg Soc Radiol. 2017 Dec 16;101(Suppl 2):15. (License: CC BY-4.0)
  2. Rha EY, Kim DH, Kwon H, Jung SN. Morel-lavallee lesion in children. World J Emerg Surg. 2013 Dec 30;8(1):60. (License: CC BY-2.0)
  3. Kontis E, Vezakis A, Psychogiou V, Kalogeropoulos P, Polydorou A, Fragulidis G. Morel-lavallée lesion: report of a case of unknown mechanism. Case Rep Surg. 2015;2015:947450. (License: CC BY-3.0)