Prosthetic joint infection by Mycobacterium tuberculosis: an unusual case report with literature review.

Prosthetic joint infection with Mycobacterium tuberculosis usually involves the hips or knees and can result from either local reactivation, or less often from hematogenous spread. Predisposing conditions include rheumatoid arthritis, chronic steroid use and pulmonary diseases. The most common symptom at presentation is pain, and the most common physical finding is joint swelling and/or a draining sinus tract. The sedimentation rate is helpful when elevated but is nonspecific, and initial skin testing is only helpful when positive. The diagnosis depends on culture and histologic examination of tissue. Removal of the joint combined with oral antituberculous treatment is necessary when the infection is discovered greater than six weeks post joint replacement. Early diagnosis leads to decreased morbidity. Tuberculous infection of prosthetic joints is a rare disease and its diagnosis depends on a high degree of clinical suspicion.