Musculoskeletal Tuberculosis

Abstract

Musculoskeletal tuberculosis (TB) accounts for approximately 10% of all extrapulmonary TB cases in the United States and is the third most common site of extrapulmonary TB after pleural and lymphatic disease. Vertebral involvement (tuberculous spondylitis, or Pott's disease) is the most common type of skeletal TB, accounting for about half of all cases of musculoskeletal TB. The presentation of musculoskeletal TB may be insidious over a long period and the diagnosis may be elusive and delayed, as TB may not be the initial consideration in the differential diagnosis. Concomitant pulmonary involvement may not be present, thus confusing the diagnosis even further. Early diagnosis of bone and joint disease is important to minimize the risk of deformity and enhance outcome. The introduction of newer imaging modalities, including MRI (imaging procedure of choice) and CT, has enhanced the diagnostic evaluation of patients with musculoskeletal TB and for directed biopsies of affected areas of the musculoskeletal system. Obtaining appropriate specimens for culture and other diagnostic tests is essential to establish a definitive diagnosis and recover M. tuberculosis for susceptibility testing. A total of 6 to 9 months of a rifampin-based regimen, like treatment of pulmonary TB, is recommended for the treatment of drug susceptible musculoskeletal disease. Randomized trials of tuberculous spondylitis have demonstrated that such regimens are efficacious. These data and those from the treatment of pulmonary TB have been extrapolated to form the basis of treatment regimen recommendations for other forms of musculoskeletal TB.

FIGURE 1

TB of the rib. Shown is a postero-anterior radiographic view of the chest of a man after 3 months of successful anti-TB chemotherapy. Note the mass in the left chest with destruction of a portion of the adjacent rib. A biopsy and culture confirmed TB. The mass resolved with continued therapy.

FIGURE 2

This photograph demonstrates a cold abscess of the chest wall in a patient with TB. Aspiration of this mass yielded material that was AFB smear positive, and the culture yielded M. tuberculosis.

FIGURE 3

Swollen knee of a patient with tuberculous arthritis. An HIV-infected patient presented with a painful, swollen knee. He had a recent history of trauma to the knee. On examination the knee was warm and an effusion was present. Culture of the synovial fluid following arthrocentesis grew M. tuberculosis.

FIGURE 4

Plain film radiograph of the lumbar spine of a patient with tuberculous spondylitis demonstrating anterior end plate destruction, sclerosis, loss of disk space, and evidence of bony debris. These findings are suggestive of tuberculous spondylitis. A CT-directed biopsy was performed to obtain material for cultures, which yielded M. tuberculosis.

FIGURE 5

CT evaluation of patients with tuberculous spondylitis. CT demonstrated a large right psoas abscess in an HIV-infected patient with tuberculous spondylitis of the lumbar spine. A percutaneous drain was placed into the psoas abscess, and the fluid culture yielded M. tuberculosis.

FIGURE 6

MRI of a patient with multifocal tuberculous spondylitis who has both thoracic and lumbar spine involvement which is not contiguous (i.e., skip lesions). The thoracic lesion reveals anterior collapse of adjacent vertebrae and a Gibbus formation leading to kyphosis. There is also evidence of lumbar disease in this patient.

FIGURE 7

Radiographs of the knee of a patient with tuberculous arthritis. (A) Plain radiograph of the knee shown in Fig. 3. Marginal erosions are visible, along with soft tissue swelling.

FIGURE 8

TB of the knee. The radiograph shows findings of TB (left) and the normal knee (right). Note the narrowed joint space, lytic bone destruction in the distal femur and proximal tibia, and soft tissue swelling in the abnormal knee, which had shown clinical evidence of TB for more than 10 years (but the patient had not undergone treatment).

FIGURE 9

TB of the hip. (A) Plain radiograph of a 12-year-old girl who presented with an abnormal gait for several months. The left femoral head is completely destroyed. (B) Operative specimen of the destroyed femoral head.

FIGURE 10

CT imaging of the knee of a patient with tuberculous arthritis, showing extensive marginal destruction as well as erosions.

FIGURE 11

CT imaging of a psoas muscle abscess. The CT shows the lower extremities in a patient with lumbar tuberculous spondylitis who has a psoas abscess that extends into the right thigh.