[Tarsal osteoarthritis: a rare localisation of tuberculosis]

We report the case of a 39-year-old woman with an uneventful medical history who presented an inflammatory left foot with no notion of trauma or fever. The plain x-ray and magnetic resonance imaging demonstrated talonavicular and subtalar osteoarthritis. A surgical biopsy with excision of inflammatory and necrotic tissue and removal of a fistular tract was performed. Histology revealed the presence of granulomas with caseous central necrosis suggesting tuberculosis of the bone. The diagnosis was confirmed when bacteriology samples grew Mycobacterium tuberculosis. Antituberculosis drugs were administered for twelve months. At 24 months, the patient presents a painful stiff rear foot after the development of secondary talonavicular degeneration. This case illustrates a particular clinical presentation of tuberculosis. This diagnosis should be considered in the presence of atypical bony lesions with a chronic course. Early diagnosis enables proper therapeutic management. Useful diagnostic imaging techniques include plain x-rays, computed tomography, and magnetic resonance imaging. Certain diagnosis is based on bacteriological and histological examinations.