1) Spinal tuberculosis commonly affects the thoracolumbar region and presents with nonspecific symptoms like backache. It can lead to abscess formation, deformity, and neurological deficits if left untreated. 2) Diagnosis involves correlating clinical findings with imaging like MRI and lab tests. Definitive diagnosis requires culture, histopathology or PCR identification of M. tuberculosis. 3) Treatment involves a 9-12 month course of multidrug antitubercular chemotherapy. Surgery may be needed for complications like deformity, instability or neurological deficits. The goals of surgery are decompression, debridement, stability and deformity correction.

1. Spinal Tuberculosis: Current
Concepts –Dr . Rajasekaran
Journal Club Meeting
SeThiNet presentations

2. Awards
North American Spine Society Outstanding Research Award consecutively for 2019 & 2020,
Asia Pacific Spine Society Best Clinical Research Award for 2019
International Society for the Study of Lumbar Spine, Canada - Prize for Spine Research for
four years – 2004,2010,2013 & 2017.

3. Epidemiology
• The incidence of extra pulmonary TB is low at 3%
• Skeletal TB contributes to around 10% of EPTB, and
• Spinal TB has been the most common site of STB – 50%
• The thoracolumbar junction remains to be the most affected region
of the spinal column followed by the lumbar spine and the cervical
spine.

4. Epidemiology
• The South East Asian Region alone had 46.5%
• The European region contributed only 3%
• The deaths related to TB remained to be one of the top 10 causes of
death worldwide.
Clinical importance
Increasing prevalence of immune deficient survivors
The emergence of multidrug resistance (MDR)

5. Pathophysiology
TB is caused by the Mycobacterium tuberculosis complex -
It is a slow-growing fastidious
Aerobic bacillus
The primary site of infections can be in the lungs, lymph nodes of the
mediastinum, mesentery, gastrointestinal tract, genitourinary system, or
any other viscera.
Spinal infection is always secondary
Caused by Hematogenous dissemination of the bacillus from a primary
focus.

6. Pathophysiology
Bacillus colonize the subchondral region of the vertebra
and forms granulomatous inflammation
Characterized by lymphocytic infiltration and
epithelioid cells, which may merge to form the classical
Langhans-type giant cells and end up in caseating
necrosis of affected tissues forming a cold abscess.
With progressive destruction of the vertebral body
leads to deformation of spine

7. Types of lesions
Paradiscal - Commonest
Central - Resulting in
vertebral body loss
Posterior - Nonosseous abscess
formation

8. Clinical Presentation of Spinal TB
The clinical picture of spinal TB is extremely variegated.
The manifestation of spinal TB depends on the
1. Severity of the disease
2. Duration of the disease
3. Site of the disease
• Insidious in onset
• Slow progression

9. Clinical presentations
Backache
Most common of all symptoms.
During the active stage
rarely can be radicular in nature.
Rest pain
The intensity is proportional to the
amount of bone destruction and
instability.
Constitutional symptoms
loss of weight
loss of appetite
fever
malaise
Cold Abscess
Cold abscess lacks inflammatory
features and initially forms in the
infective focus.
.

10. Clinical presentations…. Cold abscess
• The lumbar cold
abscess
• usually presents
as a swelling in Petit’s
triangle
• It can track down along
the psoas to cause
pseudo-flexion
deformity of the hip.

11. • In the cervical spine, it can present as a retropharyngeal abscess or
as a swelling in the anterior or posterior triangle of the neck or
even in the axilla.
• The retropharyngeal abscess can produce dysphagia, hoarseness of
voice, and respiratory stridor.

12. Clinical presentations –
Cold abscess
• Thoracic region - the cold abscess usually
presents as a fusiform paravertebral swelling
• It can track along the intercostal vessels and
presents as a swelling in the chest wall.
• Thoracic cold abscess can track down through
the arcuate ligament, or via the openings in
the diaphragm.

13. Deformity
Owing to the involvement of the anterior
column, progressive destruction results in
kyphotic deformity of the spine most often.
The clinical appearance depends on the
number of vertebrae involved causing
1. Knuckle - (1 vertebra)
2. Gibbus - (2 vertebrae)
3. Rounded kyphosis - (>3 vertebral
collapse)

14. Rajasekaran et al proposed a formula
To predict the final kyphotic deformity in adult population affected with
spinal TB
Y= a + bX
Y - Final angle
a – Constant – 5.5
b – Constant – 30.5
X - Is the initial loss of vertebral height in thoracic and
thoracolumbar spine.

15. Deformity…
• Kyphotic deformity of 60 or above is disabling and may increase the
likelihood of developing neurological sequelae.
• The vertebral loss is well tolerated in cervical and lumbar spine unlike
thoracic and thoracolumbar spine due to the inherent lordosis.
• However, rarely with active ongoing infection, progressive cervical
kyphosis may necessitate surgical intervention

16. Paediatric Spinal TB
Childhood spinal TB is considered two separate issues
1. Infectious disease
2. Spinal deformity
40% of the affected children develop severe deformity

17. Paediatric Spinal TB
Children develop rapid and more severe
deformities than an adult because the
immaturity and flexibility of the spine
In childhood TB, even after healing of
the disease, the deformity may progress
due to the growing nature of the spine.

18. Spine at risk signs -
The “spine at risk” signs to identify children at risk for severe deformity
(A) Separation of facet joints in lateral radiographs which indicates instability
(B) Retropulsion of the posterior part of the affected vertebra
(C) Lateral translation of vertebrae in the anteroposterior radiograph
(D) The toppling of one vertebra over the other vertebra.

19. Gibbus Deformity

20. Neurological Deficit
Neurological complications can occur
• Early active disease
• In the late healed stage
Early active disease – Acute direct compression due to
• Abscess
• Inflammatory tissue
• Retropulsion of the Sequestrum
• Instability and translation of spinal column
Late-onset neurological deficit due to
1. Ossification ligamentum flavum
2. Increasing deformity

21. Classification
Complicated TB - Pharmacological + Surgical
• Deformity
• Instability
• Neurological deficit
Uncomplicated spinal TB - Pharmacological management
• Diagnosis is made prior to development of such complications

22. Investigations
• Radiological investigations –
• None of the imaging options are reliable in distinguishing spinal infection and
neoplasm
• Immunoassays -
• Laboratory investigations –
• Microbiological investigation -
• Histological investigation –
• Genetic studies

23. Radiological Investigations
Plain radiographs
• Have no role in early diagnosis of spinal TB.
• Disc space narrowing
• rarefaction of vertebral end plates
• kyphosis
• instability can be made out only in late
stages.
• 60% to 70% of spinal TB may have an active
pulmonary lesion, and thus chest radiography
is essential.

24. Radiological Investigations
Computed tomography (CT)
• CT is extremely useful in identifying extent of
bony destruction
• Posterior column involvement
• Junctional pathologies
• Joint involvement
• Regional stability
• Four types of destruction have been noticed

25. Fragmentary type
Associated hypodense paravertebral
softtissue mass with bone fragments
causing spinal cord compression.
Commonest pattern

26. Osteolytic type
Second most common pattern
Anterior and central parts of
vertebral body are completely
destroyed.
Associated large paravertebral
soft-tissue mass.

27. Anterior margin of vertebral
body has irregular ragged
appearance.
Characteristic hypodense
abscesses with rim
calcification are seen in each
psoas muscle.
Subperiostel type

28. Localized sclerotic type
Least common pattern
Localized destruction with
sclerotic margins.

29. Radiological Investigations
MRI
• It has been the imaging modality of choice as it has been able to detect
earliest changes.
• Gadolinium-enhanced MRI further helps in differentiating TB from other
causes of infective spondylodiscitis.
• The extent of soft tissue involvement
• Spread of abscess
• Neural compression
• Whole spine screening aids in identifying skip lesions
• Assessing the response to treatment

30. Histopathology
• Demonstrating classical granulomas and staining of smears to
identify acid fast bacilli (AFB)
• Sensitivity - 50– 80%
• specificity - NA

31. Microbiological investigations
Culture and ABST
• Growth of Mycobacterium in culture specimens obtained from the
infected tissue is the single most confirmatory diagnostic test of
spinal TB and is considered the gold standard method.
• However, due to its very poor sensitivity - 47%
• Lowenstein Jensen media, 6-8 weeks, requires 101 to 10 2 bacilli/mL
(live bacilli)
• BACTEC radiometric culture takes 2 weeks

32. Laboratory investigations
Erythrocyte sedimentation rate (ESR) - sensitivity – 60-90%
• Usually in TB, ESR is >20 mm/ h and decreases as healing progresses
• Used to monitor therapeutic response,
• But its low specificity is a concern.
C- reactive protein (CRP) - Sensitivity - 71%
• is more specific for acute infection rather than TB.

33. Immunoassays
• Immunoassays are high in active and chronic infective stages of TB
• Would not be able to differentiate between
1. active and healed disease
2. BCG vaccinated individuals
• Not recommended - WHO

34. Immunoassays
Mantoux tuberculin skin test
• WHO recommends usage in low-income countries
• It is of no diagnostic value in endemic areas
• It may also be false negative in immunodeficient individuals
• Sensitivity - 40% to 55%
• Specificity - 75%

35. Interferon-g (IFN-g) release assays and Whole blood-based enzyme-
linked immunosorbent assays
Measuring the amount of IFN-g produced in response to
Mycobacterium tuberculosis antigens.
They are specific and differentiate between natural TB and BCG
vaccination, these tests cannot differentiate between latent TB and
active TB.
• Sensitivity - 50% to 65%
• Specificity - 85%

36. Gene Xpert MTB/RIF - 2010
• It is an automated diagnostic test that can identify Mycobacterium
tuberculosis (MTB) DNA and resistance to rifampicin (RIF).
• Sensitivity of 95.6% and specificity of 96.2%.
Xpert MTB/RIF Ultra -2017
• New generation
• More sensitivity and specificity
• Specimens with low numbers of bacilli, especially in smear-negative, culture-
positive specimens, in pediatric specimens and in extrapulmonary specimens.
Genetic studies

37. Biopsy samples should be send for
• AFB staining -
• AFB culture -
• Aerobic culture along with antibiotic sensitivity testing by line probe
assays
• Polymerase chain reaction (PCR)
• Other molecular diagnostic tests

38. Summary of diagnosis
The diagnosis of spinal TB is based on
• Correlating clinical and classical imaging findings on MRI
• Confirmed by either
1. Culture and sensitivity,
2. Histopathological evidence.
3. Gene Xpert PCR test

39. Management
Uncomplicated spinal TB Chemotherapy only
Complicated spinal TB Chemotherapy + Surgery

40. Uncomplicated spinal TB is a medical disease and can be effectively managed by
chemotherapy alone

43. MRC trials
Conclusion
• The Medical Research Council after randomly subjecting spinal TB
patients to chemotherapy alone, debridement, and radical
debridement along with fusion found similar functional outcomes in
all 3 groups.

44. Chemotherapy
• Multidrug antitubercular treatment (ATT) is the mainstay of
treatment in both complicated and uncomplicated TB.
Advantages
• Can eliminate intracellular, extracellular, dormant, or rapidly multiplying
forms and each has different growth and metabolic properties.
• Multidrug ATT reduces instances of drug resistance.

45. Chemotherapy - First line drugs
• 9 months of treatment where 4 drugs—isoniazid,
• Rifampicin,
• Pyrazinamide,
• Ethambutol, or Streptomycin
• Initiation phase —all 4 drugs for 2 months
• Continuation phase - isoniazid and rifampicin for 7 months in the

46. Chemotherapy – 2nd line drugs
• Kanamycin
• Amikacin
• Capreomycin
• Levofloxacin
More side effects
Expensive than the standard first-line ATT drugs

47. • A 2013 meta-analysis of both clinical trials and observational studies did not
find any difference between Directly Observed Treatment, Short Course (DOTS)
and Self administered therapy.
• WHO and all other TB programs continue to use DOTS as an important strategy
in fear of drug resistance.

48. Chemotherapy - Drug-Resistant TB
MDR-TB
• is that which is resistant to INH and rifampicin.
• Primarily it occurs because of improper treatment
• Resistant strains can also be communicable
Extensively drug-resistant TB (XDR-TB)
• When there is resistance to INH and rifampicin
• along with resistance to any fluoroquinolone and
• at least one injectable second-line anti-TB drugs

49. Predictors for successful outcome in MDR-TB
1. Progressive clinical improvement at 6 months following
chemotherapy
2. Radiographic improvement during treatment
3. Disease with strains that are resistant to less than 3 ATT drugs,
4. Use of less than 4 second-line drugs in treatment
5. No changes of regimen during treatment.

50. Surgical management
Indications of surgery
• Lack of response to chemotherapy or recurrence
• Severe weakness at presentation
• Static or worsening neural deficit even after initiating chemotherapy
• Instability
• Incapacitating pain
• Deformities

51. Surgical Management
Goals of treatment
The fundamentals of surgical management are
• Adequate decompression
• Debridement
• Maintenance and reinforcement of stability
• Correcting the deformity or halting the progress of deformity

52. The advantages of surgical treatment
1. Adequate sampling for histological confirmation of the diagnosis
2. Early and better healing by removal of the disease focus
3. Correction and prevention of the spinal deformity
4. Reducing the rates of recurrence
5. Promoting early neurological recovery

53. Approach
Anterior Approach
• Spinal TB mainly affects anterior column
and thus anterior approaches enable
adequate exposure, debridement, and
reconstruction.
Disadvantage
• Graft slippage – 50 -80%
• Fracture
• Absorption, or subsidence of graft.
• Mortality 4% morbidity 18%

55. Safety of instrumentation
MRC trial :Conclusions 1999
• TB bacilli is slowly growing and has little bioadhesive properties and
biofilm formation
• Titanium implants can be safely used in active spinal tuberculosis

56. Approach
Posterior approach
• Commonly used approach
• Easy, familiarity
• The ability to achieve adequate exposure for circumferential spinal cord
decompression, better deformity control through pedicle screws
• Possibility of extension of instrumentation
• Avoidance of thoracotomy-related complications
• Transpedicular decompression and posterior instrumentation facilitates
faster recovery and also prevents deformity progression and neurological
sequelae in early disease.

57. Anterior approach
Can go for thorough
debridement and application
of bone graft.

58. Complete destruction of L1 vertebra fixation by posterior approach

59. Approach
Combined Approach
Indications
• Osteoporotic bones,
• Multiple vertebral body involvement, and in
• Severe kyphotic deformities. 104
Posterior instrumentation with anterior decompression and fusion can be
performed in 1 or 2 stages.
Anterior debridement removes infected foci and allows for direct neural
decompression and rigid anterior reconstruction.
Posterior instrumentation enables better deformity correction and reduces the
stress on grafts placed anteriorly, thus helping in maintaining sagittal deformity
correction.
However, due to the high associated morbidities, combined approaches are
reserved only in severe destructive lesions and junctional pathologies that are
inherently unstable.

60. Thank you