A 44-year-old otherwise healthy Sri Lankan male presented with left ankle joint swelling of 6 months duration. He had progressive ankle swelling with restricted movement and pain while weight-bearing. He denied any respiratory symptoms, pyrexia and constitutional symptoms. Patient did not have a history of previous trauma or surgery. On examination, his left ankle joint was swollen without tenderness or warmth (Figure 1). There was global restriction of movements at the ankle joint. Apart from this, the general physical examination was unremarkable. His basic haematological tests were normal; however, his erythrocyte sedimentation rate (ESR) was 35 mm in the first hour. A Mantoux test was performed and it was positive with an induration of 18 mm. However, Ziehl-Neelsen stain for acid-fast bacilli was negative and the chest X-ray was unremarkable. Arthritis workup with rheumatoid factor (RF), anti-cyclic citrullinated peptide antibody (anti-CCP), and antinuclear antibody (ANA) was negative. His fasting blood sugar level was normal and retroviral screening was negative. X-ray of the ankle region showed irregular outline at ankle mortise and loss of joint space with an irregular articular outline at subtalar joint (Figure 2). The magnetic resonance imaging (MRI) showed a marked loss of articular cartilage with associated bone marrow oedema in the subarticular region of distal tibia extending to distal metaphyseal region (Figure 3). The subtalar joint also showed evidence of chronic inflammation. Aspiration was not possible due to minimal effusion. Since initial workup, including MRI, was inconclusive, the patient underwent open synovial biopsy which showed granulomatous type of inflammation without any Langhans type of giant cells or associated caseating granulomas. Xpert MTB/RIF test was negative; however, culture for mycobacteria was positive for Mycobacterium tuberculosis. The ankle was splinted with a back slab and was kept non-weight-bearing for the initial 2 months, followed by gradual mobilisation. Anti-tuberculosis treatment was initiated immediately after the synovial biopsy result, that is, 7 weeks after the initial presentation. Patient was treated for 2 months with isoniazid 300 mg, rifampicin 600 mg, pyrazinamide 1500 mg, and ethambutol 800 mg once daily (intensive phase), followed by 7 more months with isoniazid 300 mg and rifampicin 600 mg once daily (continuation phase). With anti-tuberculosis treatment and physiotherapy, his pain and swelling improved dramatically and he was able to bear weight by 3 months of treatment. Patient completed anti-tuberculosis treatment at 9 months and remains asymptomatic after 1-year follow-up. A repeat MRI was not performed since patient clinically improved.