Elbow Tuberculosis: A Radiological Dilemma

Background: Tuberculosis is considered to affect approximately one third of the world population. Being an airborneinfection the percentage of skeletal tuberculosis is found to be very low compared to pulmonary tuberculosis. The incidence of musculoskeletal tuberculosis affecting elbow joint is extremely rare. Materials and Methods: We present a case of a 21 year old male residing in India presented with complaints of progressive left elbow pain for 6 months with restriction of movement later. On examination, the left elbow was in fixed flexion deformity with 40degree with diffuse swelling around the joint. There is fullness in the para olecranon fossa with doughy feeling of the joint which suggests synovial hypertrophic over posterior joint line and anconeus triangle. Range of movement on flexion was 40 to 90degree; supination 0 to 70 degree and pronation 0-30 degree. Inflammatory markers on examination were elevated and revealed C-reactive protein of 29.8mg/L and Erythrocyte Sedimentation rate (ESR) of 40mm/hr. Plain radiograph of left elbow joint shows multifocal geographical areas of lytic destruction involving proximal end of ulna predominantly in olecranon process and cortical irregularity at the head of radius. Computed tomography showed multifocal lytic areas involving the olecranon process of ulna, head of radius and lateral condyle of humerus with synovial thickening around the elbow joint. Magnetic resonance imaging of elbow joint showed homogeneously enhancing diffuse synovial thickening in and around the elbow joint with resultant widening of the joint space. The hypertrophic synovium is extending within the olecranon process of ulna through multiple cortical defects. A differential diagnosis of monoarticular rheumatoid arthritis and possibility of granulomatous lesion was given. Results: The patient was admitted and a synovial biopsy was taken. The histopathology report was suggestive of granulomatous lesion with possibility of tuberculosis. Patient was conservatively managed with anti-tubercular treatment. On further follow up the patient had better mobility of the joint. Conclusion: TB of the joint should be considered in the differential diagnosis of monoarticular arthropathy or arthritis due to its indolent course. This case highlights the diagnostic challenges of TB in an appendicular joint, non-specific imaging findings, and resultant joint dysfunction. It also underscores systemic flaws in healthcare, particularly the lack of drug susceptibility testing and the limited availability of GeneXpert in endemic regions, exacerbating the practice of empirical treatment amidst the rising tide of MDR-TB