Introduction::The onset of prosthetic joint infections (PJIs) is characterized by early on-set defined as within 90 days of the procedure, delayed onset defined as within 3 to 12 months, and late onset defined as over 12 months. In only a scant number of case reports, Mycobacterium flavescens-associated infections are typically found in sputum cultures and associated with various forms of penetrating joint traumas, particularly post-surgical interventions. Due to its rarity in presentation among cases of PJIs, we have presented a case of PJI caused by Mycobacterium fla-vescens.

Case Presentation::We have, herein, reported a case of a 70-year-old male presenting with stab-bing left knee pain over the past several months along with accompanying erythema and swelling with the presence of purulent discharge. Outpatient cultures have shown the growth of Mycobacte-rium flavescent; subsequently, the patient underwent a 2-stage revision arthroplasty and was treat-ed with a three-drug regimen and implant 5 months later. Although being an atypical cause of PJIs, we emphasize the importance of considering NTM as a differential for immunocompromised patients, especially those with prior surgical intervention.

Discussion::Mycobacterium spp. related PJIs manifest clinical features similar to other bacteria-causing PJIs, such as warm, indurated edema at the surgical site resulting in wound dehiscence and joint effusion. Diagnosis of Mycobacterium spp. related PJIs includes history and physical exami-nation findings, serum inflammatory markers, synovial fluid analysis, and culture. Concurrently with surgical interventions, utilization of antimicrobial agents provides additional control in My-cobacterium-related PJI. Mycobacterium flavescens should be included among other NTMs as a possible cause of PJIs.