BACKGROUND
On physical examination, the patient’s temperature is 98.96°F(37.20°C), with a blood pressure of 129/67 mm Hg and a heart rate of 89 bpm. His respiratory rate is 20 breaths/min, and his O2 saturation is 95% while breathing room air. The patient is not in acute distress. The head, eyes, ears, nose, and throat (HEENT) examination shows well-healing facial lacerations with intact sutures. His chest is clear to auscultation on both sides, with normal cardiovascular and abdominal findings. The lower extremities have normal sensation and 5/5 strength (on a scale of 0-5, with 0 being no strength and 5 being normal strength).
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A visible fluid collection is observed in the proximal lateral aspect of his right thigh. The fluid seems to track up around the gluteus maximus muscle to the lumbosacral region, with slight crossing of the midline to the left (see patient photograph). The fluid appears to be a free-flowing, low-viscosity collection without evidence of erythema or ecchymosis. No loculation is noted on palpation, and the patient has no thickening or induration of the skin in the overlying and surrounding areas.
What is the diagnosis?
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HINT
This fluid collection was not appreciated during the patient’s previous admission to the hospital.
Authors:
Gil Z. Shlamovitz, MD, UCLA Emergency Medicine Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
Rick G. Kulkarni, MD, FACEP, Assistant Professor, Yale School of Medicine, Section of Emergency Medicine, Department of Surgery, Attending Physician, Medical Director, Department of Emergency Services, Yale-New Haven Hospital, CT
eMedicine Editor:
Eugene Lin, MD, Department of Radiology, Virginia Mason Medical Center, Seattle, Wash, Assistant Clinical Professor of Radiology, University of Washington Medical Center, Seattle, Wash
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{mosimage}ANSWER
Closed, internal degloving injury: The patient underwent computed tomography (CT) scanning of the pelvis, which showed a large, subcutaneous fluid collection extending from the region of the lumbosacral spine along the right lateral buttock to the thigh and down to the level of the femoral shaft (arrows, CT Images 1-2). The fluid collection was not present on a previous CT scan that was obtained 2 weeks before presentation (the time of the motor vehicle collision). The patient’s laboratory studies showed a white blood cell (WBC) count of 8.38 × 109/L; hematocrit, 0.363 (36.3%); platelet count, 953 × 109/L (953 × 103/µL); and an international normalized ratio (INR) of 1.0.
The patient underwent CT-guided aspiration of the fluid collection under local anesthesia. An 8F catheter was used to aspirate 800 mL of dark red fluid (see CT Image 3). Postaspiration CT images demonstrated near-complete resolution of the fluid collection (see CT Image 4), and the catheter was removed. A pressure dressing (elastic spica dressing) was applied. An elastic bandage was wrapped around the entire thigh, beginning just proximal to the knee, and continued upward across the proximal thigh and buttock. The bandage was wrapped around the waist several times and then brought back over the thigh to compress the entire lower back, buttock, and proximal thigh. The patient tolerated the procedure well and was discharged to home the following day. He was instructed to wear the compression dressing as much as possible, and a follow-up visit was scheduled. The aspirated fluid was sent for bacterial culture and found to be negative for bacteria.
A closed, internal degloving injury is a clinically significant soft-tissue injury that is associated with pelvic trauma. The subcutaneous tissue is torn away from the underlying fascia, which creates a potential space that can fill with serous fluid and/or a hematoma caused by the disruption of the arteries that perforate through the fascia mixed with viable and necrotic fat. The condition commonly occurs over the greater trochanter, but it can occur anywhere over the trunk, buttock, or thighs. When a closed, internal degloving injury occurs over the greater trochanter, the condition is known as a Morel-Lavallee lesion. As mentioned, this condition usually occurs in association with pelvic and acetabular fractures, but it can also occur in the absence of fractures. Direct crush injury to the pelvis or a high-speed motor vehicle crash are the most common mechanisms of injury. The importance of this soft-tissue injury may not be initially apparent; some patients present months after the initial event, complaining of soft-tissue swelling or contour abnormalities that are not resolving.
The diagnosis of a closed, internal degloving injury is usually based on physical findings (ie, a soft, fluctuant area over the lesion and a loss of local sensation). Diagnostic aids may include ultrasonography and CT imaging. Various methods or combinations of techniques for treating degloved areas have been suggested, including the application of compression dressings, fluid aspiration or liposuction, injection of sclerosing agents, deep fascial fenestration, prolonged closed surgical drainage, and open surgical debridement (ie, leaving the degloved area open for closure by secondary intention). A review of the available literature, while failing to reveal prospective comparisons, did demonstrate variable outcomes with different therapeutic approaches, ranging from complete resolution to the development of various complications, including infections and skin necrosis or breakdown. The complications associated with closed, internal degloving injuries often require extensive therapy and surgical management.
To determine the appropriate therapeutic modality, clinicians should carefully assess closed, internal degloving injuries while accounting for various parameters, including the size and location of the lesion, the time since the initial injury, and the patient’s comorbidities and accompanying injuries, as well as their expected management. Close follow-up should be arranged to ensure complete resolution of the injury and to diagnose post-therapeutic complications, such as infection, fluid reaccumulation, and skin necrosis.
References:
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 Jun;42(6):1046-51. [MEDLINE: 9210539]
Harma A, Inan M, Ertem K: The Morel-Lavallee lesion: a conservative approach to closed degloving injuries. Acta Orthop Traumatol Turc 2004;38(4):270-3. [MEDLINE: 15618769]
Hudson DA: Missed closed degloving injuries: late presentation as a contour deformity. Plast Reconstr Surg 1996 Aug;98(2):334-7. [MEDLINE: 8764723]
Hudson DA, Knottenbelt JD, Krige JE: Closed degloving injuries: results following conservative surgery. Plast Reconstr Surg 1992 May;89(5):853-5. [MEDLINE: 1561257]
Tsur A, Galin A, Kogan L, Loberant N: Morel-Lavallee syndrome after crush injury. Harefuah 2006 Feb;145(2):111-3, 166. [MEDLINE: 16509414]
