Page 125 - Journal of Special Operations Medicine - Spring 2016

An Ongoing Series

All That Swells Is Not a Bruise

The Morel-Lavallée Lesion

Carol L Callahan, FNP-BC, MSN, RN; Justin Eisenman, DO, MS

ABSTRACT
Frequently overlooked, Morel-Lavallée lesions are asso- Morel- Lavallée lesions are often misdiagnosed or diag-
ciated with a closed degloving or shearing mechanism nosed up to months following the initial injury. 1,2
causing a dehiscence of underlying soft tissue with for-
mation of a potential space. This space fills with blood, Case Presentation
lymph, and cellular debris, giving the lesion a fluctuant
appearance on examination. The potential space associ- A 26-year old, African American, male Special Opera-
ated with larger lesions can be a source for hemorrhage tions Forces Soldier presented with the complaint of
in the appropriate clinical context. However, these le- pain and swelling to his sacral area following a fall. He
sions are often diagnosed late in their clinical course or reported that 6 days earlier, he had fallen against the
are misdiagnosed, leading to long-term complications. side of a metal table-like structure at a playground and
Management of this injury typically depends upon the slid to the ground. Since then, he noticed persistent pain
size of the lesion. This article discusses a Morel-Lavallée and an enlarging bulge at the site of impact. He was ini-
lesion in an active-duty Servicemember requiring treat- tially evaluated at his troop medical clinic (TMC) 2 days
ment by a plastic surgeon and includes the pathophysi- after injury. On examination, it was noted that he had
ology of Morel-Lavallée lesions, diagnostic strategies, an area of swelling at L4–S1 with moderate to severe
and management pearls. pain on palpation, as well as decreased lumbar range
of motion. He was prescribed oxycodone/acetyl-para-
Keywords: Morel-Lavallée; injury, degloving; injury, shear- aminophenol (acetaminophen) and methocarbamol
ing; pain, back and directed to apply cool compresses to the affected
area. He presented again to his TMC 2 days later for
increased pain, and a worsening area of swelling esti-
mated at 6cm diameter over the lumbar spine area. He
Introduction
was subsequently directed to the emergency department
The Morel-Lavallée lesion is an frequently overlooked (ED) for further evaluation.
condition that was first described by the French phy-
sician Maurice Morel-Lavallée in 1853. Often char- On examination in the ED, the patient was noted to be
1
acterized as a closed degloving injury, Morel-Lavallée uncomfortable with sitting and standing. There was an
lesions occur as a result of shearing forces applied at estimated 6cm × 6cm area of fluctuance at the L5–S1
the junction of subcutaneous tissue with muscle fascia level with no overlying erythema or induration (Figures
or bone, resulting in formation of a cavity or potential 1 and 2). The patient had a normal neurologic examina-
space. Disruption of surrounding capillaries leads to a tion and no further systemic complaints.
2
leak of blood and lymphatic fluid, filling the potential
space and creating an effusion containing a milieu of An ultrasound (US) scan of the dorsal lumbar paraspi-
blood, lymph, and necrotic tissue. An ensuing inflam- nous soft tissues demonstrated a predominately anechoic
matory reaction results in the formation of a peripheral fluid collection between the deep fascial layer overlying
capsule, which may account for the perpetuation and the erector spinae musculature and the deep subcuta-
occasional slow growth of this lesion. For this reason, neous fat (Figure 3). Both the underlying musculature

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