Tuberculous osteomyelitis masked by concomitant staphylococcal infection

A systematic and easily reproduced bone protocol was used over a 14-month period to evaluate bone histologically and by mycobacterial culture in patients with chronic osteomyelitis. On examination of 140 bone specimens, we found four patients with unsuspected tuberculous osteomyelitis whose diagnosis was obscured by a concomitant staphylococcal osteomyelitis. Three of the patients had axial skeleton involvement, and one had disease of the femur. No patient had a history of a positive skin test or of tuberculous disease, and none had coexistent pulmonary disease. The underlying granulomatous infection was initially revealed in one patient by histologic examination of bone and in three others only by mycobacterial culture of bone. Concomitant osseous tuberculosis should be excluded in patients with staphylococcal osteomyelitis. Evaluation using a bone protocol with histologic study and culture on Löwenstein-Jensen medium is effective in diagnosing occult osseous tuberculosis.