Delayed Onset of Pediatric Morel-Lavallée Lesion: A Case Report

Abstract

Introduction: A Morel-Lavallée lesion (MLL) is a closed degloving injury secondary to shearing forces. MLL is a rare, easily overlooked diagnosis, especially in those without recent trauma or fracture. Patients will present with ecchymosis, edema, fluctuance, and skin hypermobility or tightness. We present a case of pediatric MLL that was initially challenging to diagnose as the inciting trauma was 2 months before her diagnosis.

Case report: A 14-year-old girl presented with 5 days of left leg bruising, swelling, and pain. Two months prior, she collided with another softball player's cleat and developed a hairline fracture. Magnetic resonance imaging of the left lower extremity (LLE) showed a closed, soft-tissue degloving injury, and she was diagnosed with a MLL. Throughout her admission, she had improvement in her bruising but continued to have pain with ambulation that was somewhat alleviated with the use of a compression stocking. Pediatric Orthopedic Surgery and Interventional Radiology were consulted, and a conservative approach was recommended with 3 months of LLE compression.

Conclusion: MLL typically occurs in patients in their 30-40s and rarely occurs in children. Identifying MLL in children is essential as children are more susceptible to shock and multi-organ damage from blunt trauma than adults. They are also more vulnerable to fractures and deep organ injuries. In the setting of MLL, children can quickly develop hypovolemic shock due to lower blood volumes and necrosis secondary to mass effect in the dead space. MLL should be included on the differential for children with trauma or a history of a shearing injury.

Keywords: Pediatrics; bruising; orthopedics; trauma.

Figure 1

Anterior and lateral view of the left lower extremity on presentation to the emergency department on the day of admission.

Figure 2

Sub-Figure 1 is the frontal view and sub-Figure 2 is the lateral view of the patient’s left lower extremity witch arrows indicating the anterior, medial, and lateral subcutaneous soft-tissue edema of the proximal and mid leg.

Figure 3

Ultrasound still image with arrows indicating the complex fluid collection in the lateral subcutaneous soft tissues.

Figure 4

Lateral left lower extremity upon presentation to the medical floor <5 h after Figure 1 was taken.

Figure 5

Magnetic resonance imaging images confirming Morel-Lavallée lesion. Sub-Figure 1- Axial T1 image without fat saturation demonstrates fat globules in the collection. Sub-Figure 2 - Axial T1 image with fat saturation shows loss of signal of the globes confirming the presence of fat. Sub-Figure 3 – Axial T2 image with fat saturation demonstrates crescent-shaped fluid collection tracking through the subcutaneous fat.

Figure 6

Anterior and lateral view of the left lower extremity on discharge.