(P86) Morel-Lavallée Lesion: Point-of-Care Ultrasound Assessment of Soft Tissue Trauma in the Emergency Department

Chief Complaint : The patient complains of left thigh pain that is getting worse after he got in a car accident the previous day.

History of Present Illness : A 21-year-old male without past medical history presented complaining of worsening left thigh pain and swelling following a motor vehicle accident the previous day. Immediately after the accident he was evaluated at an outside hospital for an uncomplicated laceration to his right lower extremity.

Pertinent Physical Exam: GENERAL: Healthy appearing, well-developed.
PSYCH: Alert and Oriented to person, place and location. Normal memory, mood, and affect.
HEENT: Normocephalic, atraumatic, pupils equal and reactive bilaterally, Moist mucous membranes
CARDIOVASCULAR: Regular rate and rhythm, no murmurs, rubs, or gallops.
LUNGS: Clear to auscultation bilaterally, no wheezing.
ABDOMEN: Abdominal tenderness
SKIN: Warm, well perfused. No skin rashes or abnormal lesions.
MSK: Ecchymosis along the left superolateral thigh with marked fluctuance
NEURO: Ambulating with no limitations. Normal muscle strength and tone. No focal deficits.

Vitals signs included: BP 124/71, HR 97, RR 23, 98.4 F.

Pertinent Laboratory Data: Hemoglobin: 16.1. All coagulation studies were normal.

Case Discussion: Physical exam revealed ecchymosis along the left superolateral thigh with marked fluctuance. The emergency physician (EP) performed a point-of-care ultrasound (POCUS), visualizing an anechoic fluid collection deep to the subcutaneous adipose. A subsequent computed tomography (CT) with contrast demonstrated a high-density soft tissue fluid collection deep to subcutaneous adipose but superficial to the underlying fascia consistent with a Morel-Lavallée (MLL) injury. The patient was admitted for surgical drainage and discharged the next day in stable condition.

MLL is an internal degloving injury secondary to shearing forces separating the superficial subcutaneous tissue from the muscular fascia (1). Disruption of the capillaries and lymphatic structures leads to accumulation of hemolymph and necrotic fat that may encapsulate (1,2). It is often missed in the setting of polytrauma (1,3). Untreated, MLL may progress to skin necrosis, infection, poor cosmesis (1).

Point-of-care ultrasound is a useful diagnostic imaging modality for the rapid identification of MLL. POCUS will demonstrate an anechoic or hypoechoic fluid collection deep to the hypodermis but superficial to underlying fascia. Internal echogenic debris, such as necrotic fat globules, may be visualized as well (3,4). This case illustrates the strong efficacy of point of care ultrasound in the early diagnosis of Morel-Lavallée injury. Due to the severe complications of MLL injuries, ultrasound should be the preferred diagnostic modality for these cases.

References and Acknowledgements (Optional): 1. Scolaro, John A. MD, MA; Chao, Tom MD; Zamorano, David P. MD The Morel-Lavallée Lesion: Diagnosis and Management, Journal of the American Academy of Orthopaedic Surgeons: October 2016 - Volume 24 - Issue 10 - p 667-672 doi: 10.5435/JAAOS-D-15-00181

2. De Coninck, T., Vanhoenacker, F., & Verstraete, K. (2017). Imaging Features of Morel-Lavallée Lesions. Journal of the Belgian Society of Radiology, 101(S2), 15. DOI: https://doi.org/10.5334/jbr-btr.1401

3. Scott LaTulip, Rameshwar R. Rao, Alan Sielaff, Nik Theyyunni, John Burkhardt, "Ultrasound Utility in the Diagnosis of a Morel-Lavallée Lesion", Case Reports in Emergency Medicine, vol. 2017, Article ID 3967587, 3 pages, 2017. https://doi.org/10.1155/2017/3967587

4. Neal C, Jacobson JA, Brandon C, Kalume-Brigido M, Morag Y, Girish G. Sonography of Morel-Lavallee lesions. J Ultrasound Med. 2008 Jul;27(7):1077-81. doi: 10.7863/jum.2008.27.7.1077. PMID: 18577672.