Abstract: A 68-year-old female presented with skin ulceration in the left knee tibial tuberosity surgical scars for 3 days, with a history of total knee arthroplasty 5 years ago. Routine bacterial culture of wound swabs showed Mycobacterium fortuitum. We thought that the pathogenic bacteria of this case was from the external environment according the course of disease, the image data of the soft tissues infection around the prosthesis, the intact fascia layer. The patient was treated with anti-tuberculosis drugs and a skin graft surgery, and the patient is improving.

Key words: Mycobacterium fortuitum, total knee arthroplasty, skin infection