Background: Mycobacterium chelonae (M. chelonae), a non tuberculous mycobacteria (NTM) commonly found in soil and water, is seldom involved in joint or tendon sheath infections. Thus, only 16 arthritis, 11 tenosynovitis, and 2 concomitant arthritis and tenosynovitis due this bacterium are available in the literature, with varying issues.
Case Report: We report here a case of both digital tenosynovitis and interphalangeal arthritis due to M. chelonae occurring in a 73 years old man. This patient was not immunodepressed nor had underlying inflammatory rheumatism. He developed a painful oedema of the left middle finger, treated with several corticosteroids infiltrations. Worsening of the oedema and of the pain occurred, leading to a surgical washing of the finger. Mycobacterial culture completed by genotypic analysis leaded to the diagnosis of Mycobacterium chelonae infection. The patient healed with combination of digital synovectomy and prolonged antibiotic treatment. In order to improve the management of tenosynovitis and arthritis due to M. chelonae, we reviewed the literature and reported here the main messages.
Conclusions: As for our patient, in eighteen cases of the literature, supposed direct inoculations of M. chelonae during prosthetic joint replacement or corticosteroid infiltration were found. Patients with underlying chronic rheumatism or immunosuppressive treatment were most likely to have arthritis or tenosynovitis. M. chelonae was commonly sensitive to clarithromycin, doxycyclin, and members of the aminoside class. Osteo-articular infections due to M. chelonae require prolonged antibiotic therapy associated to surgical treatment. Although the mortality due to arthritis and tenosynovitis was comparable, the functional prognosis seemed worse in tenosynovitis as compared to arthritis. Asepsis rules during surgical or infiltration remains the best warrant to avoid M. chelonae osteo-articular infection.

Keywords: Atypical mycobacteria, synovitis, Iatrogenic Disease