Clinical features of tuberculous septic arthritis in Khon Kaen, Thailand: a 10-year retrospective study.

Tuberculous septic arthritis is difficult to diagnose. A retrospective analysis was done on patients over 15 years of age who attended Srinagarind Hospital, Khon Kaen, Thailand, between January 1, 1997 and December 31, 2006, whose synovial fluid culture was positive for Mycobacterium tuberculosis. The medical records of 77 patients were reviewed; one-third were in their sixth decade. Comorbid disease was found in 33 cases (42.9%), with systemic sclerosis being the most common (9 cases) followed by diabetes mellitus (5 cases) and chronic kidney disease (5 cases). Chronic monoarthritis was the most common presentation (34 cases) followed by acute monoarthritis (20 cases). More than half of the polyarticular involvements were disseminated tuberculosis. The knee was the most commonly affected joint (36.4%). Sixty percent had delayed diagnosis due to an incorrect diagnosis. Abnormal chest radiography and blood eosinophilia were found in 40 and 57.3% of cases, respectively. Synovial fluid and synovial tissue staining for acid-fast bacteria were positive in 30 and 40% of cases, respectively. A caseous granuloma was present in 57.5% of cases and non-specific synovitis in 12%. Sixty-three percent had bone erosions. Tuberculous septic arthritis should be considered in patients who present with acute or chronic monoarthritis, and who have an abnormal chest radiograph or eosinophilia. Polyarticular involvement was commonly related to having disseminated tuberculosis and may indicate systemic involvement of tuberculous infection.