Date post: | 20-Jul-2016 |
Category: |
Documents |
Upload: | endy-destriawan |
View: | 24 times |
Download: | 1 times |
TUBERCULOUS SPONDYLITIS
Marsilah Binti Mohammad Kamarulzaman
112012239
DEFINITION A spinal infection associated with
tuberculosis and characterized by a sharp angulation of the spine where tubercle lesions are present. Also called Pott's disease.
ETIOLOGY Mycobacterium tuberculosis-
extrapulmonary tuberculosis spread via hematogenous or miliary TB.
Predisposing conditions: - Chronic disorders. - Diabetes. - Drug abuse. - Prolonged corticosteroid medication. - AIDS. - Other disorders resulting in reduced
defence mechanisms.
INCIDENCE Bone and soft-tissue tuberculosis
accounts for approximately 10% of extrapulmonary tuberculosis cases and between 1% and 2% of total cases.
Tuberculous spondylitis is the most common manifestation of musculoskeletal tuberculosis, accounting for approximately 40-50% of cases.
Pott Disease is related to socioeconomic factors and historical exposure to the infection.
Male-to-female ratio of 1.5-2:1 In the United States and other
developed countries, Pott disease occurs primarily in adults. In countries with higher rates of Pott disease, involvement in young adults and older children predominates.
PREDILECTION The usual sites to be involved are the
lower thoracic and upper lumbar vertebrae, it is probably secondary to urinary tract tuberculosis through hematogenous route.
The commonest area affected is T10 to L1.
PATHOPHYSIOLOGY
Mycobacterium tuberculosis enters the lung through
inhalation of air that contain bacilli or Mycobacterium bovis transmitted through milk which is not adequately sterilized or
has been contaminated.
Within the lung, the tubercle bacilli incite a granulomatous type of inflammatory reaction.
Phagocytic macrophages engulf the bacilli.
Nevertheless, tubercle bacilli are able to survive
and multiple even in intracellular environment
The turbecle is relatively avascular, its central
portion eventually becomes caseous.
The turbecle may be healed in the form of
fibrosis. Even in healed tubercles, living tubecles tend to persist in dormant
state and are capable reactivation in
immunocompromise patient
Widespread via the blood stream occurs months or
years later, during a period of lowered
immunity.
Granulomatous inflammation is
characterized by slowly progressive bone
destruction in the anterior part of a vertebral body and is accompanied by regional osteoporosis.
Spreading caseation prevents reactive new
bone formation and at the same time renders segments of bone avascular, thereby
producing tuberculous sequestra.
Tuberculous granulation tissue penetrate the thin cortex of the vertebral
body to produce paravertebral abscess.
The infection spreads up and down the spine under the anterior and posterior
longitudinal ligamnets.
Progressive destruction of bone anteriorly and
resultant anterior collapse of the involved vertebral
bodies lead to progressive kyphosis (posterior
angulation)
CLINICAL FEATURES The onset is gradual/slowly. Back pain. Fever, night sweats, anorexia
and weight loss. Signs may include kyphosis (common)
and/or a paravertebral swelling. Affected patients tend to assume a
protective upright, stiff position.
DIAGNOSIS History of previous infection or recent
contact with tuberculosis. The sedimentation rate is elevated. The tuberculin skin test result is
positive.
RADIOGRAPHC EXAMINATION
Osteolytic lesion in the anterior part of a vertebral body.
Regional osteoporosis. Narrowing of the adjacent intervertebral
disc. Extensive anterior destruction,
involvement of other vertebrae. Paravertebral abscess
CONFIRMED DIAGNOSIS Aspiration of paravertebral pus which is
studied microscopically for tubercle bacilli.
Tissue obtained either by closed punch biopsy or open surgical biopsy reveals the typical histological picture of tuberculous infection.
DIFFERENTIAL DIAGNOSIS Pyogenic osteitis of the spine. -Pain and stiffness in the back which
may be of rapid onset. -The causal agent is predominantly
Staphylococcus. The vast majority of cases resolve after systemic administration of the appropriate antibiotic.
TREATMENT Antituberculosis drugs must be continued for
at least 1 year. - Intensive phase treatment (5 or 6 months) Isoniazid 300-400mg Rifampicin 450-600mg Fluoroquinolones 400-600mg - Continuation phase treatment (9 months) Isoniazid & Pyrazinamide 1500mg for 4
½months Isoniazid & Rifampicin for 4 ½ months - Prophylactic phase (3 or 4 months) Isoniazid & Ethambutol 1200mg
Nourishing diet. Immobilisation of the spine is usually for
2 or 3 months. After 1 month of drug therapy and
rest,the spinal lesion is most effectively treated by open operation to evacuate the tuberculous pus, to remove tuberculous sequestra as well as diseased bone.
PREVENTION As for all tuberculosis, BCG vaccination. Improvement of socio-economic
conditions. Prevention of HIV and AIDS.
COMPLICATION Paraplegi (Pott’s paraplegi)- The paraplegi of active disease
develops early- results from extradural pressure or from direct involvement of the spinal cord by tuberculous granulation tissue.
- The paraplegi of healed disease develops late- results from the gradual development of body ridge that impinges on the spinal canal or from progressive fibrosis.
Rupture of thoracic paravertebral abscess into the pleura to produce tuberculous empyema.
In the lumbar region, pus may enter the iliopsoas muscle and spread distally as a psoas abscess. Example of ‘cold abscess’.
- Cold abscesses are defined as having no associated erythema, heat, or tenderness.
PROGNOSIS The progress is slow and lasts for
months or even years. Prognosis is better if caught early and
modern regimes of chemotherapy are more effective.
A study from London showed that diagnosis can be difficult and is often late.