Tuberculosis infection of the talonavicular joint

Isolated tuberculosis osteomyelitis affecting the foot is extremely rare. Symptoms are nonspecific and haematological investigations are often unhelpful making diagnosis difficult. We report the case of a 41-year-old female who presented with a 7-month history of a painful hindfoot following a minor ankle sprain. Inflammatory markers were mildly raised and initial radiographs showed only some mild narrowing of the talonavicular joint. MRI scanning suggested osteomyelitis centred over the talonavicular joint. Open biopsy confirmed areas of caseous necrosis but no acid-fast bacilli were seen. The final diagnosis was confirmed with culture of mycobacterium tuberculosis. A good recovery was seen following debridement and commencement of anti-tuberculosis chemotherapy. Unless an awareness of this condition exists, the diagnosis and therefore the appropriate treatment can often be delayed which may lead to significant consequences for the patient.