Abstract

Introduction:
Morel-Lavallée lesions (MLLs) are rare closed degloving injuries caused by shearing forces, leading to hemolymphatic fluid collections. They are commonly associated with motor vehicle trauma and may result in infection, chronicity, and soft tissue complications if not treated promptly.

Case Presentation:
A 75-year-old male presented with extensive right thigh swelling following a motor vehicle collision. Imaging, including ultrasound, CT angiography, and MRI, confirmed a large encapsulated MLL with secondary infection. Initial management involved intravenous antibiotics and staged surgical debridement with capsulectomy and dead space reduction.

Management and Outcome:
Due to recurrence and delayed healing, definitive reconstruction was performed using a proximally pedicled medial gastrocnemius split muscle flap. The procedure successfully obliterated the dead space and improved wound healing. The patient achieved satisfactory functional recovery, with residual swelling managed conservatively.

Conclusion:
This case highlights the importance of early diagnosis, imaging—particularly MRI—and a multidisciplinary approach in managing complex MLLs. Advanced reconstructive techniques play a crucial role in achieving favorable outcomes, especially in elderly patients with comorbidities.