Mycobacterium Tuberculosis Monoarthritis of the Knee in Children: A Case Report

Abstract

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.

Figure 1

(a,b) – AP (a) and lateral (b) radiographs of the right knee. Overall alignment is anatomic, with the presence of a knee effusion. No osseus pathology observed.

Figure 2

(a,b) – Coronal section of T2-weighted MRI (a) and sagittal section of T2-FS weighted MRI of the right knee demonstrating diffuse synovitis and free intra-articular bodies.

Figure 3

(a, b) – Intra-operative photographs demonstrating synovitis (a,b) and free-floating articular bodies (a).

Figure 4

(a,b) – a. Histopathology slide (100x power) of resected synovial tissue demonstrating granulomatous synovitis with central focal necrosis (black arrow). Histopathology slide (400x power) re-demonstrating granuloma with focal necrosis.