Mycobacterium tuberculosis monoarthritis is a rare form of TB, occurring in 1-2% of cases in the United States. Delays in definitive diagnosis and subsequent treatment are common. While case reports of tuberculous arthritis have been presented in international literature, there is a relative paucity of literature from within the United States. Given the difficulty in diagnosis and adverse outcomes of delayed diagnosis, we present the case of an 11-year-old otherwise healthy male with isolated monoarticular TB septic arthritis of the right knee. A discussion, including review of current literature, regarding presentation, diagnosis, and treatment of tuberculous monoarthritis follows. The emerging role of arthroscopy as a diagnostic and treatment modality for tuberculous monoarthritis of the knee is discussed.
Level of evidence: VI.