Proximal tibial tuberculous osteomyelitis with secondary knee joint arthritis: A case report.

Tuberculous osteomyelitis is an uncommon form of musculoskeletal tuberculosis and most frequently involves long bones such as the femur and tibia. We report the case of a 53-year-old woman presenting with a one-year history of progressive pain and swelling of the left knee. Imaging revealed a well-defined lytic cavitary lesion in the metaphyseal-epiphyseal region of the proximal tibia with cortical breach, intra-articular extension, and direct communication with a pre-tibial soft-tissue abscess. Surgical management included debridement and curettage of the intramedullary cavity, drainage of the pre-tibial collection, PMMA cement filling, and a knee joint washout. Histopathological analysis demonstrated epithelioid granulomas with Langhans-type giant cells and caseous necrosis, and PCR confirmed Mycobacterium tuberculosis. This case highlights the importance of considering tuberculous osteomyelitis in the differential diagnosis of chronic osteolytic lesions with associated soft-tissue collections or secondary joint involvement, particularly in endemic regions.