Mycobacterium tuberculosis (MTB) is a rare cause of prosthetic joint infection. The diagnosis is challenging
especially in cases of latent tuberculosis. QuantiFERON-TB Gold (QFT®) is an interferon-gamma relative assay
(IGRA) which is highly specific and sensitive for detection of MTB infection. We report a case of 76-year-old lady
diagnosed with tuberculous prosthetic joint infection following total knee replacement. Histological examination of
abnormal synovial tissue taken intraoperatively reveals chronic granulomatous lesion and raised suspicion of
tuberculous infection in otherwise asymptomatic patient. The tuberculin skin test, MTB acid-fast stain and
tuberculosis polymerase chain reaction were negative. The diagnosis dilemma was solved with positive result of
QuantiFERON TB Gold Test. The patient was treated with anti-tuberculous drug without any surgical intervention.
At five months follow-up, patient was clinically well with no symptoms and signs of infection.