Guest Post: Morel-Lavallée Lesion: A Rare Diagnosis for Lateral Hip Pain Following Trauma

What should we do when we encounter an unusual musculoskeletal differential diagnosis in clinic? While in fellowship practice, we do a CAT (critically appraised topics). CATs are an in depth analysis of a research article that answers your carefully thought-out clinical question. I completed this CAT after evaluating a patient with a Morel-Lavallée lesion. This lesion can occur after a shearing injury most commonly from a MVA or fall of over 10 feet. This lesion is rare and commonly missed however the patient’s prognosis depends on early detection of this lesion. Please see attached CAT and power point to learn more about this rare diagnosis and what we should be aware of as we are doing our patient subjective and objective exam.

---

The Mayo Clinic sought to retrospectively collect data on patients with the diagnosis of Morel-Lavallée Lesion and aggregate data regarding the patient presentation, diagnosis, and treatment. This study provides initial evidence to support diagnosis of Morel-Lavallée Lesions through mechanism of injury, patient symptoms, and confirmation with MRI or CT scan.1 Level 4 evidence: retrospective case series.

Citation: Nickerson TP, Zielinski MD, Jenkins DH, Schiller HJ. The Mayo Clinic experience with Morel-Lavallee lesions: establishment of a practice management guideline. J Trauma Acute Care Surg 2014;76:493-7.

Article co-author’s name and email: Henry Schiller; schiller.henry@mayo.edu.

Three part clinical question: In a 21 year old female with post-traumatic hip pain from a 20 foot fall, what is the best way to rule in a Morel-Lavallée lesion as a source of the patient’s pain?

Search Strategy:

Databases included PubMed, PEDro, Cochrane Database of Systematic Reviews, and National Guideline Clearing House. Through PubMed an initial search under Clinical Queries of “Morel-Lavallée lesion AND diagnosis” with category: diagnosis and scope: broad produced 39 hits and 2 systematic reviews. Search of PEDro, Cochrane Database, and National Guideline Clearing House included the same search terms without results. A subsequent search was performed using “Morel-Lavallée lesion”, “closed degloving injury”, and “posttraumatic seroma” without results. Triage of articles was limited to the PubMed results and due to the limited results, all abstracts were reviewed for applicability. Several abstracts were eliminated as they were a single case report or did not address diagnosis of the lesion. Ten articles were reviewed in their entirety, all were either level 4 or 5 evidence.

Background:

Morel-Lavallée Lesions are closed degloving injuries representing a severe traumatic separation of the skin and the subcutaneous tissue from the underlying fascia. The mechanism of injury is usually trauma that occurs tangential to fascial planes, resulting in a shearing type of injury which has been reported in motor vehicle collisions, falls from 10 or more feet, and contact sports.2 This creates a cavity that is filled with lymph or blood, resulting from the disruption of arteries perforating through the fascia and a mixture of viable and necrotic fat.3,4 After the cavity fills with fluid, a formation of a hematoma or seroma may occur. The inflammatory reaction that follows this injury if not treated in the acute phase can organize the granulation tissue into a fibrous capsule. The capsule prevents the absorption of the fluid and is thought to be the cause of recurrent fluid collection.5

Documented diagnosis and treatment has varied greatly in the literature. Patient presentation typically includes a traumatic mechanism of injury6, swelling, diminished sensation, and pain hours or days after the traumatic event.7 Imaging techniques to confirm a diagnosis include MRI, ultrasound, and CT.7,8 Depending on when the lesion is identified, treatment can include needle aspiration, incision drainage with compression, surgical debridement, and percutaneous drainage with irrigation, suction drainage, and debridement.3,9 Accurate and early diagnosis of this lesion plays a significant role in treatment options and prognosis of patients with a Morel-Lavallée Lesion.

The Study:

While Morel-Lavallée lesions are associated with considerable morbidity in trauma patients, there is a lack of consensus in how to identify and treat these patients.3,5 The Mayo clinic sought to define the factors associated with failure of percutaneous aspiration in order to better identify patients requiring immediate operative management. This study sought to establish a practice management guideline in this rare diagnosis.

Methods: The authors retrospectively searched the Mayo Clinic’s American College of Surgeons Level 1 trauma center database for patient records containing the terms “Morel-Lavallée, closed degloving injury, or posttraumatic seroma” from February 2, 2004 through December 23, 2011. They identified 79 patients with 87 Morel-Lavallée lesions. Patients with masses that were not filled with seroma fluid or with open degloving injuries were excluded. For all included patients, demographic information was collected. The authors also collected information regarding the lesion location, size, associated injuries, primary treatment, and wound course. The patients were divided into a non-operative management (NONOP), percutaneous aspiration (ASP), or operative drainage or debridement (OR) group. Univariate analysis was performed; factors associated with the type of the lesion management and recurrence were compared amongst the groups. Multivariable analysis was also done for features that were clinically relevant and nearing statistical significance.

Subjects: 79 patients were identified with 87 Morel-Lavallée lesions. There were 41 patients in the OR group, 21 in the NONOP group, and 25 in the ASP group. The mean age was 48 (OR), 44 (NONOP), and 41 (ASP). Total age range for all three groups was 14-88 years old. The percentage of males in each group was 54% (OR), 48% (NONOP), and 56% (ASP). A high-energy injury occurred in 54% (OR), 52% (NONOP), and 64% (ASP) of these patients. Recurrence of the lesion occurred in 15% (OR), 19% (NONOP), and 56% (ASP) of the patients with risk of recurrence at 1 year 16% (OR), 11% (NONOP), and 44% (ASP).

Are the results of this diagnostic study valid?

This study is at risk for selection bias which is a threat to is validity. The authors collected information from a single group of patients, in a single geographical area, and these patients sought treatment at a single trauma center. The patients included in this study comprise a limited group of people which might not be applicable to the greater population. For example, each of these patients were treated at a level 1 trauma center which may account for why many of the lesions were associated with high-energy mechanisms of injury (56%) or motor vehicle accidents (25%). Perhaps another hospital without a trauma center would find a lower association between the prevalence of the lesion in association with trauma.

The authors did a retrospective review of electronic medical records and noted occasional incomplete records and reasons for intervention not always documented. They used the Kaplan-Meier analysis to determine the risk of recurrence while censoring patient lost to follow-up. This leaves the study at risk for inaccurate or incomplete data regarding the diagnosis and recurrence of the lesion.

The Evidence:

This study is a descriptive study of the patient presentation, diagnosis, and treatment of patients with a Morel-Lavallée lesion, rather than a purely diagnostic study. Therefore, conclusions drawn regarding the patient presentation and the diagnostic study utilized to confirm the presence of the lesion is a low level of evidence. Identifying common patient presentation and the best utilized imaging tool can assist the provider in correctly identifying a patient that should have a differential diagnosis of a Morel-Lavallée lesion. Patient presentation that providers should consider are patients with a high-energy mechanism of injury as 56% of the lesions found had a high-energy mechanism, 25% of which were motor vehicle collisions. There were no differences found in sex, BMI, DM, smoking history, or alcohol use. The most common locations were thigh (32%), flank (17%), and hip (16%). Diagnosis was made via CT, MRI, US, and US with MRI. CT was used most frequently as the providers were also looking for fractures.

Are the valid results of this diagnostic study important?

Due to the lack of diagnostic evidence presented in this study, it is not possible to determine the statistical importance of clustering the patient presentation and correct image in the diagnosis of a Morel-Lavallée lesion. This study could provide initial evidence for future studies comparing the diagnostic utility of CT, MRI, US, or MRI and US. Other studies have described the characteristics of these imaging tools for Morel-Lavallée lesion3-8,10 but no study exists comparing the sensitivity or specificity of each image. This study could also provide initial evidence for future studies investigating the patient characteristics that lead to earlier diagnosis versus delayed diagnosis. This would be important as delayed diagnosis and treatment of a Morel-Lavallée lesion can lead to a poorer prognosis for the patient.5,6

Can you apply this valid, important evidence in caring for your patient?

This study presents evidence of a lesion that can occur after a shearing, high-mechanism of injury to the thigh, flank, or hip. This would be an important differential diagnosis to consider in a deployment scenario where military members are at high risk for falls or trauma associated with blast injuries. The mechanism of injury presented in this study is applicable to the patients a deployed physical therapist may see in a direct access setting. Unfortunately the availability for advanced imaging may be limited in a deployment setting. The age of the patients presented in this study range from 14-88 with a mean age of 44 which is consistent with the population of patients at Brooke Army Medical Center (BAMC). At BAMC, however, physical therapists do not frequently have the opportunity to practice in a direct access setting and patients most at risk will likely be referred by their primary care manager and may already have imaging ordered. This differential diagnosis should be considered in patients who present to physical therapy with a history of trauma, that have persistent pain lasting past the expected time frame of healing.

Bio: Rachel Condon is an active duty physical therapist in the United States Navy. She earned her DPT from Saint Louis University in 2010 and then went on to Great Lakes Naval Base. While at Great Lakes she eventually became the Physical Therapy Department Head and lead the way by expanding services to include Pelvic Physical Therapy and Telerehab. She pursued continuing education by earning her CSCS and Trigger Point Dry Needling credentials. These skills served her well on her second assignment on the USS Theodore Roosevelt where she served as the primary care provider for all musculoskeletal injuries. She is currently earning her DSc and FAAOMPT through the Army-Baylor University Fellowship in Orthopedic Manual Physical Therapy at Brooke Army Medical Center in San Antonio, TX.

References:

1. Nickerson TP, Zielinski MD, Jenkins DH, Schiller HJ. The Mayo Clinic experience with Morel-Lavallee lesions: establishment of a practice management guideline. J Trauma Acute Care Surg 2014;76:493-7.

2. Bonilla-Yoon I, Masih S, Patel DB, et al. The Morel-Lavallee lesion: pathophysiology, clinical presentation, imaging features, and treatment options. Emerg Radiol 2014;21:35-43.

3. Hak DJ, Olson SA, Matta JM. Diagnosis and management of closed internal degloving injuries associated with pelvic and acetabular fractures: the Morel-Lavallee lesion. J Trauma 1997;42:1046-51.

4. Mellado JM, Bencardino JT. Morel-Lavallee lesion: review with emphasis on MR imaging. Magn Reson Imaging Clin N Am 2005;13:775-82.

5. Weiss NA, Johnson JJ, Anderson SB. Morel-lavallee lesion initially diagnosed as quadriceps contusion: ultrasound, MRI, and importance of early intervention. West J Emerg Med 2015;16:438-41.

6. Parra JA, Fernandez MA, Encinas B, Rico M. Morel-Lavallee effusions in the thigh. Skeletal Radiol 1997;26:239-41.

7. Goodman BS, Smith MT, Mallempati S, Nuthakki P. A comparison of ultrasound and magnetic resonance imaging findings of a Morel-Lavallee lesion of the knee. PM R 2013;5:70-3.

8. Puig J, Pelaez I, Banos J, et al. Long-standing Morel-Lavallee lesion in the proximal thigh: ultrasound and MR findings with surgical and histopathological correlation. Australas Radiol 2006;50:594-7.

9. Powers ML, Hatem SF, Sundaram M. Morel-Lavallee lesion. Orthopedics 2007;30:250, 322-3.

10. Mukherjee K, Perrin SM, Hughes PM. Morel-Lavallee lesion in an adolescent with ultrasound and MRI correlation. Skeletal Radiol 2007;36 Suppl 1:S43-5.