Morel-Lavallée Lesions (Internal degloving injuries) of the Lower Extremity in the Pediatric and Adolescent Population.

PURPOSE: To describe the largest case series of lower extremity traumatic internal degloving injury i.e. Morel-Lavallée lesion (MLL) in the pediatric and adolescent population, its treatment and outcomes.

METHODS: Retrospective review of patients under 18 years who presented with MLL to a tertiary children's hospital. Demographic, clinical, radiographic, treatment and outcomes data were collected. Descriptive statistical analysis was conducted.

RESULTS: 38 patients having MLL with mean age 14.6 years were classified into 2 groups: hip/thigh MLL (9 patients) and lower leg MLL (29). Most common cause of lower leg and hip/thigh MLL was sports injury (79.3%) and motor vehicle accident (MVA) (33%) respectively. Most implicated sports were football and baseball. Primary care physicians/pediatricians were the initial treating providers for 63% of patients. Imaging modality of choice was magnetic resonance imaging (MRI) for lower leg MLLs (72.4%) and ultrasonography(US) for hip/thigh MLL (66.7%). 25 (65.8%) patients were treated with conservative management, 12 (31.6%) with minimally invasive methods and 1 (2.6%) needed surgical management. Average return to normal activities took 14.3 and 9.1 weeks for hip/thigh and lower leg MLL respectively. 24 patients with adequate documentation demonstrated lower extremity functional score (LEFS) and pain level of 74/80 (92.5%) and 0.7/10 respectively at mean 12.5 months follow-up.

CONCLUSION: In contrast to adult injury literature, pediatric MLLs are more common in the leg/knee than hip/thigh region and caused mostly by sports injuries. Primary care physicians are the initial treating providers for the majority of the patients. Intervention is more often needed in the hip/thigh MLLs as opposed to non-operative management for lower leg injuries. This large case series on MLL in the pediatric population demonstrates differences in the management of hip and thigh lesions when compared to the management of the knee and leg lesions in the majority of these patients. Non-operative management in the majority of these lesions provided overall satisfactory outcomes.