Tuberculosis of peripheral joints: a dilemma in diagnosis

15 cases of peripheral joint tuberculosis presenting to a tertiary referral hospital are reviewed. The presentation is characterized by an insidious onset with a slowly progressive, painful, ankylosed or swollen monarthropathy with a mean length of history of 6.5 +/- 7 years. The knee joint was involved in 7 patients, hip in 6, elbow and shoulder 1 each. Significant systemic toxicity was absent, the white count was normal (mean 7.3 +/- 2.4 x 10(9)/1) and the erythrocyte sedimentation rate (ESR) was only slightly elevated (mean 31 +/- 23 mm/first h). Features of extra-articular pulmonary tuberculosis were present in 7 patients and periarticular findings were present (abscesses in 7 and sinuses in 4 patients). Despite a characteristic presentation, the diagnosis was initially missed in 10, leading to delay in instituting correct treatment. One patient presented with osteoarthritis and a Baker's cyst. Definitive joint arthropathy was present in all patients. The highest diagnostic yield was with a combination of synovial histology, synovial fluid culture and direct smear examination for acid fast bacilli (14 patients) and lowest if direct smear examination was used alone (2 patients). Chemotherapy with rifampicin and isoniazid alone (3 patients) or with at least 1 other drug was given for a mean of 15 +/- 5 months. Apart from debridement/drainage surgery, fusion/excision arthroplasty was performed in 6 cases and one had a total knee replacement. A heightened diagnostic acumen is needed in such cases.