A case of Mycobacterium fortuitum prosthetic joint infection successfully treated medically without prosthesis explantation or joint debridement.

A 58-year-old man with a history of end-stage degenerative joint disease developed a postsurgical infection at the right hip 4 weeks after hip replacement surgery. He underwent surgical washout of the right hip without opening the joint capsule. Arthrocentesis returned positive for Mycobacterium fortuitum He was started on antibiotics with the recommendation to remove the prosthesis. The prosthesis was retained. Based on antimicrobial susceptibilities, he was treated with 4 weeks of intravenous therapy using cefoxitin and amikacin and later switched to oral ciprofloxacin and doxycycline for 5 additional months. Eighteen months from his initial hip replacement surgery, he continues to do well. Joint aspiration culture is important to make a diagnosis of prosthetic joint infection (PJI) when periprosthetic culture is not available. In the absence of serious systemic or comorbid joint conditions, PJI due to M. fortuitum can be managed medically without having to remove the prosthesis or debride the joint.