Atypical Mycobacterial Infections of the Upper Extremity.

Atypical mycobacterial infections of upper extremity synovial-lined structures are often misdiagnosed and unrecognized. Despite an increasing incidence, lack of physician awareness of these pathogens may result in considerable delay in diagnosis and management, potentially leading to permanent disability. The authors conducted a literature review and analyzed 31 cases of penetrating atypical mycobacterial infection to better understand the clinical characteristics and to evaluate their posttreatment complication rate compared with available literature. Medical records for culture-positive cases of tenosynovial or intra-articular atypical mycobacterial infections of the upper extremity that were treated were retrospectively reviewed. Treatment outcomes were analyzed against published case reviews and case series. Thirty-one cases of penetrating atypical mycobacterial infection were identified. Mycobacterium marinum (n=11) was the most common organism and was associated with aquatic exposure. Twenty-eight cases received empiric treatment, 17 of which received contraindicated treatment. Patients saw an average of 5 physicians prior to receiving an accurate diagnosis, and the mean time to diagnosis was 10 months. All cases received antibiotic treatment in addition to surgical management. Twenty cases (68%) failed treatment outcomes. Delay in diagnosis and inappropriate management of atypical mycobacterial infections may lead to a treatment failure rate that is higher than what has been reported in the literature. Mycobacterium avium and M fortuitum had significantly higher failure rates than other organisms. A high index of suspicion is required to make a diagnosis and prevent residual disability. [Orthopedics. 2018; 41(3):e383-e388.].