INTRODUCTION: Morel-Lavallée lesion (MLL) is a posttraumatic closed degloving 
soft tissue injury, in which the subcutaneous tissues are separated from the 
underlying fascia. Surgical treatment is recommended if conservative management 
fails. The conventional surgical treatment for the lesion is surgical drainage 
and debridement.
PRESENTATION OF CASE: A 51-year-old male patient presented with swelling of the 
right thigh incurred during a traffic accident. The lesion was diagnosed with 
MLL. The MLL was successfully treated with a minimally invasive arthroscopic 
treatment after failure of conservative treatment. The arthroscopic treatment 
was chosen because of the patient's comorbidity that posed a risk of surgical 
wound complications. In addition, negative pressure wound therapy (NPWT) was 
performed postoperatively to ensure healing and to prevent recurrence of the 
lesion. The patient was successfully treated and the healing of the lesion was 
also confirmed with MRI.
DISCUSSION: In a patient with a risk of wound complications due to a 
comorbidity, this minimally invasive arthroscopic treatment is useful. In 
addition, NPWT was used to ensure healing and to prevent recurrence. Although 
the use of NPWT combined with endoscopic treatment has not been reported, 
additional NPWT reported in this case may be helpful to ensure healing.
CONCLUSION: In case of MLL with a risk of surgical complications, the 
arthroscopic treatment is a reasonable method and achieves the goal of an open 
surgical debridement without increased morbidity.