[Isolated osseous tuberculosis : Differential diagnosis of treatment refractory osteomyelitis?]

We report the case of a 66-year-old female patient with a treatment refractory disorder of wound healing of the knee, who had already been treated several times surgically and with antibiotics for several months. The examination revealed a skin defect with a fistula in the region of the knee joint. The X‑ray imaging showed an extensive bony defect of unclear etiology. After specific diagnostics for acid-resistant rod-shaped bacteria, it was possible to identify Mycobacterium tuberculosis as the causative pathogen. After antitubercular drug treatment complete healing of the lesions was observed. The bony defect could be filled with bone substitute. There was neither a history of primary foci nor of a potentially infectious environment.