tuberculosis of bones and joints

TUBERCULOSIS OF

BONES AND JOINTS

Historical aspects

Oldest recognized disease of mankind

Percival Pott presented the classic

description of spinal tuberculosis in 1779

Robert Koch discovered Mycobacterium

tuberculosis in 1882

Predisposing factors

• Malnutrition's

• Poor sanitation

• Living in crowded areas

• Close contact with TB patients

• Immunodeficiency states

Lesions of individual bones

• Spine

• Greater trochanter

• Phalanx

• Skull

Joint lesions

infection by mycobacterium tuberculosis of one or

more extradural components of spine namely the

vertebra, intervertebral discs, paraspinal soft tissues

and epidural space

Tuberculosis of spine

Pathophysiology

• Usually by hematogenous route

• Midthoracic spine and the region below it is

more frequently involved

• Usually two continuous vertebrae are involved

but several vertebrae may be effected

• Skip lesions or solitary vertebral involvement

may occur

Clinical features

Constitutional

symptoms

Malaise

Loss of

appetite/weight loss

Night sweats

Specific features

Stiffness

Enlarged lymph

nodes

Neurodeficit

Imaging modalities

• Conventional radiographs

• CT

• MRI

• Ultrasonography

1.Conventional Radiographs

• Reduced disc space

• Blurred paradiscal margins

• Destructions of bodies

• Loss of trabecular pattern

• Increased prevertebral soft tissue shadow

• Subluxation/dislocation

• Decreased lordosis/kyphosis

Central type of lesion:

• Spread through batson’s venous plexus/

branches

of posterior vertebral artery

• Minimal disc space reduction

• At the end concentric collapse

Anterior type lesion

Starts beneath the anterior longitudnalligament & periosteum

Collapse & disc reduction usually minimal & occurs late

Erosion is primarily mechanical

Appendicular type

Rare

Isolated infection of pedicles/lamina/transverse process/spinousprocess

Erosions

Paravertebral shadows

Intact disc space

Lateral shift & scoliosis:

• More destruction of vertebral body on one

side

• Posterior articulation involvement in addition

to usual paradiscal lesions

Skipped lesions:

• More than one TB lesion present in vertebral

column with one or more healthy vertebrae in

b/w the 2 lesions

• 7% on routine x-rays

• More frequently detected on CT/MRI

Healing is indicated by

• decreased soft tissue shadow

• Disappearance of erosions

• Return of normal density(mineralization)

• Bony ankylosis

CT & MRI

• the extent of involvement

• presence of epidural component

• cord compression

• Irregularity of both end plate and anterior

aspect of vertebral bodies

• Bone marrow edema

• Enhancement on MRI

T2 Weighted sagital image of lumbar spine shows altered

Marrow signals involving anterosuperior margin.

Ultrasonography

To diagnose the presence of tubercular

abscesses in dorsolumber vertebral disease

UltrasoundJoint effusion may be the

only finding but is

nonspecific.

Difference

TB spondylitis

a pattern of mainly bone destruction

• relative disc preservation(destruction is late sign)

• focal and heterogeneous contrast enhancement of the vertebral body

• well-defined paraspinal area of abnormal signal intensity

Pyogenic spodylitis

a pattern of mainly discitis

mild to moderate peridiscal

bone destruction

relative diffuse and

homogeneous contrast

enhancement of the vertebral

body

Difference

TB spondylitis

vertebral intraosseous rim

enhancement on sagittal

views.

Calcification when present

indictes TB.

Pyogenic spodylitis

• ill-defined paraspinal area of

abnormal signal intensity

• peridiscal rim enhancement

Tuberculous

dactylitis

spina = short bone

ventosa = expanded with air

• Plain Radiography is the modality of choice

• Tends to affect the bones distal to tarsus and wrist

• upper limb being more commonly involved

• involved bone shows a diaphyseal expansile lesion

• a periosteal reaction is uncommon

• healing is by sclerosis and is usually gradual

Poorly defined lytic change with medullary expansion, cortical erosion

and mild periosteal reaction in the mid and distal aspect of the right

middle finger in a patient with TB dactylitis.

Calvarial tuberculosis

• Rare entity

• May be localized and well defined

• Or may be more diffuse

• Associated with cold abscess

1)Lateral radiograph shows large circumscribed lytic lesion in frontal bone.

2) AP radiograph demonstrates a large frontoparietal lytic lesion suggestive

of diffuse spreading type.

3) Frontal radiograph shows a lytic lesion with a sclerotic margin.

Joint Lesions• One of the common cause of infectious arthritis in

developing countries

Never a primary lesion it is always a sequelae of

pulmonary or lymph node tuberculosis

It can occur at any age.

Radiographic features

Plain film

early stages (stage of synovitis and

arthritis)

• periarticular demineralisation

• joint space widening (due to joint effusion)

• mild subchondral erosion

late stages (stage of erosion and destruction)

• gradual narrowing of joint space (there is involvement of

articular cartilage)

• severe subchondral erosion and destruction

• pathological subluxation and dislocation

• fibrous ankylosis

• atrophic changes in bones may occur and lead to

atrophic arthropathy (seen in shoulder joint as carries

sicca)

CT degree of bone destruction or rarely sequestrum

Extension of infection in surroundings or any sinus tract

formation can also be demonstrated on post contrast

scan.

Caries sicca : there is erosion and destruction of humoral head and

glenoid cavity with soft tissue swelling, along with fibrotic opacites in the

right upper and middle lobe.

Osteolytic lesion in distal shaft of radius with osteopenia

There is a lucent lesion in the medial tibial metaphysis with thinning of

the cortex, subtle periosteal reaction and faint calcification in the

adjacent soft tissue.

Many Thanks