Multidrug-Resistant Musculoskeletal Tuberculosis: An Aggressive Clinical, Radiological and Molecular Confirmation With Genotypic Drug Susceptibility Testing Approach

Introduction Increasing evidence suggests that musculoskeletal tuberculosis (MSTB) causes significant morbidity due to the late presentation of symptoms and lack of accurate diagnosis. We aimed to assess the utility of two modalities, viz. radiology and molecular methods, in the early diagnosis of MSTB. Also, the rate of resistance to two basic first-line antitubercular drugs in musculoskeletal TB cases among clinically suspected patients was analyzed. Methods Samples from 119 patients with clinical suspicion of musculoskeletal TB were included. A radiological workup of patient and smear microscopy, mycobacterial culture, real-time multiplex polymerase chain reaction (PCR), cartridge based nucleic acid amplification test (CBNAAT), and line probe assay (LPA) of samples were carried out. Results Maximum positivity (69.74%) was observed by real-time multiplex, followed by CBNAAT and LPA (68.9%), mycobacterial culture (40.3%), and smear microscopy (19.3%). One additional advantage of using multiplex PCR was the detection of non-tuberculous mycobacteria (NTM) isolate. Forty-five strains (54.9%) on LPA were susceptible to rifampicin and isoniazid, eight (9.8%) were rifampicin mono-resistant, seven (8.5%) were isoniazid (INH) mono-resistant, and 22 (26.8%) were multidrug resistant. Conclusions MSTB diagnosis can be expedited by the combination of radiology and molecular methods. The positivity rate escalates, turnaround time improves, and the additional advantage of detection of drug resistance is added when this algorithm is included for clinching the diagnosis of MSTB.