ABSTRACT
BACKGROUND: Osteoarticular tuberculosis (OATB) is a severe form of extrapulmonary tuberculosis (TB), which causes notable morbidity and warrants a high index of suspicion for prompt management. The diagnosis of OATB poses a challenge, because of the difficulty of collecting the samples and, secondarily, the paucibacillary nature of lesion, which gives poor sensitivity and reproducibility, with long turnaround time of routine/conventional laboratory tests and the requirement for invasive procedures and expertise. The Xpert MTB/RIF assay has been approved by the World Health Organization as a rapid diagnostic tool for diagnosing pulmonary and extrapulmonary TB. AIM: To emphasize the diagnostic efficiency of gene Xpert for OATB in suspected patients in a tertiary care hospital of Eastern India. METHODS: This retrospective study was conducted in the Department of Microbiology and Orthopaedics by analyzing the data of the gene Xpert assay over a 3-year duration from January 2018 to February 2021. Demographic and clinical data were recorded. The diagnostic efficiency of gene Xpert was evaluated against the composite reference standard (CRS). RESULTS: A total of 37 cases fell into positive, probable, and possible categories of osteoarticular TB out of 112 patients included in the study by CRS; gene Xpert result was positive in 35 out of the 37 different CRS categorized cases. Of the 112 cases, culture was put in 40 cases, and, of these cultures, 5 cases showed the growth of MTB. Of these, 4 cases were included in the 35 cases diagnosed by gene Xpert. Smear microscopy was positive in 6 out of 37 CRS categorized cases. When compared with CRS, the sensitivity of gene Xpert assay, culture, and smear was found to be 94.6%, 13.5%, and 16.2%, respectively, while specificity in all the three types of tests was 100%. When kappa statistics were applied, the percentage of agreement gene Xpert, culture, and microscopy with CRS was found to be 95%, 20%, and 22.6%, respectively. Follow-up of the gene Xpert positive patients after getting anti-tubercular treatment revealed improved conditions. CONCLUSION: Gene Xpert could detect 31 extra cases with a low and very low mycobacterial load that were missed by the routine culture methods. Hence, more samples should be processed for molecular diagnostic methods like gene Xpert along with other conventional methods for the validation of the molecular test prospectively for the timely diagnosis of osteoarticular TB.
ABSTRACT
Access to the cystic lesion of the talar body without damage to the articular surface is difficult. This case report is about a 23-year-old man who had a symptomatic huge cystic lesion in the left-sided talus bone. Radiograph and CT scan showed an expansile lytic lesion within the talar body. The MRI revealed a well-defined lesion with fluid-fluid levels. The needle biopsy aspirate was haemorrhagic, and hence a diagnosis of the aneurysmal bone cyst was made. As the lesion was beneath the talar dome with an intact neck and head, a medial approach with medial malleolar osteotomy was performed. The lesion was curetted out, and the cavity was filled up with a morselised bone graft. The limb was splinted for 6 weeks, and complete weight bearing was started after 3 months. At 1-year follow-up, the lesion was found to be healed up, and the patient was pain-free with no recurrence.
