Skeletal
Tuberculosis
(Part-1)
Dr. Sunil Arora
Junior Resident
Deptt. of Chest &TB
Govt. Medical College, Patiala.
1
Introduction
Skeletal TB accounts for 10 to 35 percent of cases
of extrapulmonary tuberculosis.
 After Lung and Lymph nodes,skeletal TB is the
next common type.It constitutes about 1-4% of total
TB cases.(More In HIV-infected patients)
Skeletal
TB
generally
occurs
due
to
hematogenous spread from a primary focus.
Coexisting pulmonary TB is seen in appr.50%
cases
Pathogenesis
• It produces similar response as in lungs i.e. Chronic
granulomatous inflammation.The disease process
can start either in bone or in the synovial membrane.
• Active focus forms in the metaphysis (in children) or
epiphysis (in adults) and the inflammation extends
peripherally along the shaft to reach the
subperiosteal space.
• The inflammatory exudate may extend outward
through the soft tissue to form cold abcess and
sinuses.The affected bone may undergo fracture.
• Metaphyseal infection reaches the joint through
subperiosteal space by penetrating the capsular
attachment.In adults,the inflammation can
spread up to the subchondral area and enter the
joint at the periphery where synovium joins the
cartilage which leads to the loosening the
attachment of articular cartilage and joint
displacement.
• The epiphyseal plate is not destroyed as the
cartilage is resistant to destruction by the TB
inflammatory process.
• Sometimes the synovium is infected first and the
bone is infected secondarily.It is usually in the form
of low-grade synovitis with thickening of the synovial
membrane and leading to the formation of
pannus.Eventually,the
articular
cartilage
is
destroyed,joint gets distended with pus,which may
burst out to form a cold abcess or discharging
sinus.The joint may also get subluxated due to the
laxity of the joint capsule and ligaments.
• Fibrous ankylosis is a common outcome of healed
tuberculosis of the joints except in spine where bony
ankylosis follows more often.
Types
Two classical forms of disease have been seen;granular and
and exudative(caseous) that involve the bone and
synovium.Both the patterns have been observed in patients of
skeletal TB,one form may predominate.
1.Osseous granular type :-often follows trauma
-insidious onset,constitutional symptoms rare,
-soft tissue are slightly warm and tender
-healing without residual joint scarring&ankylosis
2. Osseous exudative(caseous) type:-rapid onset,constitutional symptoms,muscle pain and
spasm more marked
-soft tissue are warm,swollen and tender
-caseous material penetrates into jointdestructive arthritis
-healing by joint scarring&ankylosis
Classification
 TUBERCULAR SPONDYLITIS- 50%
TUBERCULAR VERTEBRAL OSTEOMYELITIS
TUBERCULAR DISCITIS
 TUBERCULAR ARTHRITIS- 30%
HIP JOINT
KNEE
WRIST JOINT
SACROILIAC JOINT
ANKLE JOINT AND FOOT
SHOULDER JOINT
 TUBERCULAR OSTEOMYELITIS- 19%
LONG TUBULAR BONES
SHORT TUBULAR BONES
FLAT BONES- RIBS,STERNUM, SCAPULA, PELVIS
 TENOSYNOVITIS/BURSITIS- 1%
Pott’s Spine
• Tubercular spondylitis has been documented in
ancient mummies from Egypt and Peru and is
one of the oldest demonstrated disease.Percival
Pott presented the classic description of spinal
TB in 1779.
• Spinal TB constitutes about 50% of all cases of
osteoarticular TB.
• MC site: Lower thoracic and lumber region
followed by middle thoracic and cervical
vertebrae.
Regional Distribution
•
•
•
•
•
•
1 Cervical 12%
2 Cervicodorsal 5%
3 Dorsal 42%
4 Dorsolumbar 12%
5 Lumbar 26%
6 Lumbosacral 3%
Anatomy
• Vertebre develops from the sclerotome on either
side of notochord
• Each pair of sclerotome (common blood supply)
form Lower half of one vertebra and upper half
of one below it along with intervening disc.
• Therefore ,infections via the arteries involve the
embryological section.
Patterns of Vertebral
Involvement
Four patterns :
• Paradiscal
• Central
• Anterior
• Appendiceal
(Posterior)
Paradiscal
• Commonest type
• Spread through arterial supply
• Bacteria lodge in the contiguous areas of two
adjacent vertebrae  granulomatous
inflammation leading to erosion of vertebral
margins loss of nutrition of intervertebral disc
Disc degeneration
• When the intervertebral discs have been
completely destroyed,the adjacent bodies fuse
with each other.
Central Lesions
• Body of single vertebra is affected.
• Starts in the centre of the vertebral body.
• Infection at this site probably reaches through
Batson’s venous or branches of post.vertebral artry.
• Lytic area develops in the centre of vertebral body
leading to balooning of vertebral body mimicking
tumour
• Later stages-concentric collapse resembling
Verebra Plana.
• Disc space is not/minimally affected
• Anterior lesions— Infection starts in the
anterior part of vertebral body and spreads
under the ant. Longitudinal ligament.
• Post/Appendiceal— Pedicle,lamina,spinous
process or transverse process of vertebra are
affected.
Clinical Features
• Constitutional symptoms,such as fever, night
sweats,loss of weight and appetite may occur before
symptoms related to spine.
1. Pain-can be Localised to the site(MC early
symptoms)
Radicular
worsen with activity and at night(night
cries)
2. Stiffness-Protective mechanism of body where
paravertebral muscle go into spasm to prevent
movement at the affected vertebra.
3. Cold abcess- Patient may present the first time with
swelling(cold abcess) or due to its compression effects:Retropharyngeal abscess --Dysphagia,dyspnea,
Hoarseness of voice
Mediastinal abscess
--Dysphagia
Psoas abscess
-- Flexion deformity of hip
-No usual signs of inflammation like heat ,redness etc.
-Follows paths of least resistance along facial
planes,blood vassels &nerves.
Presentation of cold abscesses from
different regions of spine
• Cervical spine- Exudate collects behind prevertebral facia
and may protrude as Retropharyngeal abscess, It may
track down in mediastinum to enter into trachea,esophagus
or pleural cavity.It may spread lateraly into sterno-cleido
mastoid and form abscess in neck.
• Thoracic spine- It may confined locally and may appear
on X-ray as fusiform or bulbous paravertebral abscess .It
can compress spinal cord or penetrate the ant.longitudinal
ligament to form a mediastinal abscess or pass downward
through medial arcuate ligament to form lumber abcess.
• Lumber spine- Most commonly enters the psoas
sheathPsoas abscess,also abscess in scarpa’s
triangle,medial aspect of thigh
4.Fallacious history of trauma- Trauma may draw
attention to a pre-existing lesion or may activate a latent
tubercular focus
5. Paraplegia-Rarely it is the presenting symptom.
6. Wedging :Dorsal spine : Line of weight bearing passes ant to
vertebrae.Ant wedging occurs.In late stages leading to
kyphotic deformity
Cervical and lumber spine : Wedging is less due
lordotic curvature
7. Gibbus-If patient presents late
Examination
1.
2.
Gait- Patient walks with short steps to avoid jerking the
spine.In TB of cervical spine,patient often supports his
head with both hands under the chin and twists his
whole body in order to look sideways.
Attitude and deformity :Cervical spine : Stiff,straight neck
Thoracic spine : Kyphus or gibbus,walks very
carefully
Lumber spine : Loss of lumber lordosis
3. Paravertebral swelling- Superficial cold abcess may
present as fullness or swelling on the back,along the
chest wall, usually fluctuant. It is important to look for
cold abcesses in not so obvious locations,depending
upon the region of spine involved.
4. Neurological Examination- To determine if there is any
neurological compression and to determine level and
severity of neurological compression
5. General examination- For any active or healed
lesion,for any other systemic illnesses
like,diabetes,HT,jaundice etc.
Investigation
Radiological examination :1. Xray spine-AP,Lateral
2. CXR-for primary focus
3. Xray abd-KUB,if psoas abcess is
suspected or to find out Primary in abd.
 The classic roentgen triad in spinal tuberculosis
is primary vertebral lesion, disc space narrowing
and paravertebral abscess.
 On an avg. 2.5 to 3.8 vertebrae are involved
1.



Paradiscal : Reduction in disc space- Initialy there is
demineralization with indistinct bony margins-gradually
disc space narrowing occurs.The disc space may
eventualy disappear leading to wedging.
Lateral X-ray is better for evaluation of disc space.
Takes 3-5 months for bony destruction to become
visible on X-ray
More than 30 % of mineral must be removed from
bone for a radiolucent lesion to be visible
Radiological Examination
2. Central : Lytic area in the centre of vertebral body which
enlarges and baloons out like tumour.Disc space is
preserved.
3. Anterior : Shallow excavation on anterior or lateral
surface of vertebral body.
4.TB of posterior elements is usually not detected in early
stages in radiographs.
Late Stages --Kyphotic deformity,lateral shift and
scoliosis,if one side of vertebrae is completely destroyed
Hemivertebrae
Signs of healing—bone density improves,sclerosis,
fusion of contiguous vertebrae.
Skip lesions as involvement of non contiguous vertebrae
(7 – 10 % cases).
Tuberculous spondylitis. Lateral radiograph demonstrates
obliteration of the disk space (straight arrow) with destruction of
the adjacent end plates (curved arrow) and anterior wedging.
There is narrowing of the disk space at L4-5,
with end plates indistinctly outlined. CT
section through the disk space clearly
shows destructive changes of the disk and
vertebral end plate characteristic of
infection
X-ray dorsolumbar spine showing vertebra plana of T10 vertebra.
Disc space is well maintained.
Subligamentous spread of spinal tuberculosis. Lateral radiograph
demonstrates erosion of the anterior margin of the vertebral
body (arrow) caused by an adjacent soft-tissue abscess.
Destruction of the right side of the vertebral body and the neural arch, with
the remainder of the body maintaining its shape. The lower disc space is
narrowed on the right side; the upper space is almost normal and there is a
small paravertebral abscess.
X-rays of cervical region showing retropharyngeal
abscess.
Evidence of cold abcess on X-rays
Paravertebral abcess : Paravertebral soft tissue
shadow corresponding to the site of affected
vertebrae in AP view can
• Fusiform [bird nest abcess] : L>W,seen in dorsal
spine area.
• Globular or tense : W>L,pus under pressure a/w
paraplegia
• Widened mediastinum : Abscess from dorsal
spine may present as widened mediastinum
• Aneurysmal phenomena : Concave erosions
along the margins of vertebral bodies produced
by long standing tense paravertebral
abcess,usually in dorsal spine
• Retropharyngeal abcess : In cervical spine
TB,seen on lateral view : increase in soft tissue
thickness (>4mm) in front of C3 vertebral body.
• Psoas Abcess : In dorso-lumber and lumber
TB,psoas shadow on X-ray of abd may show a
bulge.
CT Scan
• CT demonstrates abnormalities earlier
than plain radiography. It is of great value
in the demonstration small paravertebral
abscess,not otherwise seen on plain X-ray
or any calcification within the cold abscess
or visualizing epidural lesions containing
bone fragments.
A CT scan showing destruction of the neural arch on both sides,
as well as of the vertebral body. Arrows, anterior spinal abscess
Tuberculous spondylitis. Axial
CT scan demonstrates lytic
destruction of the vertebral
body (black arrow) with an
adjoining soft-tissue abscess
(white arrow).
Calcified psoas abscess.
Axial CT scan demonstrates
bilateral tuberculous psoas
abscesses with peripheral
calcification (arrows).
MRI
• Investigation of choice to evaluate the type and
extent of compression of cord,to know the spread of
disease under the anterior or post.ligament, most
effective to demonstrate neural compression,helps
to differentiate between TB and pyogenic infection :TB – Thin and smooth enhancement of the abcess
wall
Pyogenic – Thick and irregular
• MRI is more sensitive than x-ray and more specific
than CT in the diagnosis of spinal tuberculosis.
Cord changes
• Conventional radiograph-no information
• CT –inadequate assesment
• MRI -gives invaluable information
Cord oedema or focal myelomalacia is
seen as hyperintense signal and It can
also diagnose extraosseous extradural
granuloma.
‘Gibbus formation’ in the thoraco-lumbar region of a patient with spinal
tuberculosis (left). The magnetic resonance shows spinal tuberculosis at
T10–T12. Spinal tuberculosis causes the destruction, collapse of vertebrae
and angulation of vertebral column
X-ray of cervical region which shows spinal tuberculosis of cervical six
to seven vertebrae and a retropharyngeal abscess (left). T1-weighted
image of an MRI of same patient, which shows destruction of C6–C7
vertebrae
T2WI MRI-bilateral psoas abscess
Myelography
• To determine the level of obstruction
• May be indicated in cases with ‘spinal
tumour syndrom’
• In cases of multiple vertebral lesion
• When pt has not recovered after
decompression
• FNAC : Especially of cold abcess,ZN Stain,C/S
• Biopsy : May be required in cases of doubtful
diagnosis
• Other Investigation : To support the diag:Increased ESR,Decreased Hb,relative
lymphocytosis,Mantoux
Differential Diagnosis
• Congenital defects like Schmorl’s disease,
Scheurermann’s disease.
• Infetious conditions like Acute pyogenic,Typhoid
spine,Brucella spondylitis,Mycotic Spondylitis,Syphillis
• Tumours Conditions :Benign : Hemangioma,Giant cell tumour,Aneurysmal
bone cyst.
Malignant : Ewing’s sarcoma,Osteogenic
sarcoma,Multiple myeloma,secondaries
• Traumatic conditions
Treatment
• Before availability of ATT,mortality rate was 30
% or severe crippling deformities
• Aim of treatment is to achieve healing of disease
& to prevent,detect early and promptly any
complication like paraplegia
• Rest: Bed rest for pain relief and to prevent
further collapse and dislocation of diseased
vertebrae.in children body cast is used.For
cervical spineMinerva jacket&coller
• Building up of patient’s resistance : High protein diet.
• ATT : This remains the cornstone of management,
completed by rest,nutritional support and splinting, as
necessary.However, there is difference of opinion
reg.the duration of drug therapy.Short course
chemotherapy for nine months has shown good results
in patients with disease coused by succeptible
microorganisms.
• Antibiotics : For persistently draining sinuses which get
secondary infection.
• Bed soar care and to treat other comorbid conditions.
• Mobilisation : Gradual as improvement begins
 sit & walk,the spine is supported with
coller(cervical),brace (dorso-lumber spine)
• Cold abcesses may subside with ATT,if present
superficially may need aspration(antigravity
insertion of needle through a zig-zag tract) or
evacuation(wound closed without a drain)
• Sinuses: Mostly heal within 6-12 weeks.If no
improvement  Excision of tract
Indication for surgery
1. Doubtful diagnosis where open biopsy is
necessary
2. Failure to respond to ATT
3. Radiological evidence of progression of
bony lesion or paraspinal abcess shadow.
4. Imminent vertebral collapse.
5. Instability of spine and subluxation or
dislocation of vertebral body.
Procedures
1. Anteriolateral decompression with interbody bone
grafting.Grafts placed anteriorly.
2. Costo transversectomy with dempression
3. Metallic implants& titanium cage filled with
cancellous bone when whole body is destroyed.
4. Kyphotic deformity is prevented by ant
debridement,ant inerbody fusion&post fusion.
Pott’s Paraplegia
• It is a most serious complication of spinal
TB,incidence is appr 20%.
• MC in dorsal spine because it is the
narrowest region,abcess remains confined
under tension and even a small
compromise can lead to neurological
deficit,infection is common in this area and
spinal cord terminates below L1
• Early onset paraplegia- occurs during
active phase of disease,usually within 2
yrs-favourable prognosis
• Late onset- After many yrs,poor prognosis
Causes of Paraplegia
• Early onset:Inflammatory causes- Abcess(MC)
Granulation tissue
Circumscribed TB focus
Post spinal disease
Infective thrombosis
Mechanical causes- Seuestrum in canal,infected
degenerated disc in canal,pathological dislocation
• Late Onset:Reccurance
Internal gibbus
fibrous septa following healing
Grades of Paraplegia
I. Negligible
-
Patient unaware of Neuro-deficit, physician detects
extensor planter and ankle or patella clonus
II. Mild
-
Patient aware of deficit but manages to walk
with/without support+signs of spasticity.
III. Moderate
IV. Severe
-
-
Non ambulatory because of severe
weakness,paraplegia in extension on
examination.
Pt unable to walk,Paraplegia in flexion with severe
muscle spasm,near complete loss of sensation
with sphincter disturbance.
Management
• Usually possible to diagnose clinically and by typical
radiological signs.CT scan may be done to see type of
vertebral
destruction,cause
of
paraplegia
i.e.pus,sequestra etc
• Treatment of Paraplegia: Three schools of thought:1.Immediate operative decompression, of cord by ant
debridement
improvement
occurs
in
short
time.Otherwise TB penetrates the duramaterrecovery
impossible.
2.Initially immobilisation or complete bed rest,if no
improvement in specified time than surgery.
3.Middle path regimen-wait for 4 weeks to recover with
rest and ATT,if no improvement than surgical
decompression.
Principles of Treatment
• Reverse the cause -drugs or operation.
• Support the spine
• Rehabilitative measures to regain strength and to
prevent contractures.
1.Conservative: ATT &restabt 80% improve
2.Surgery:If indicated.
Indication for surgery in patients
with spinal TB and paraplegia
• Absolute indications :-Onset of paraplegia during conservative Tt or
paraplegia remaining stationary or getting worse with
conservative Tt
-Persistance or complete loss of motor power for
one month despite conservative Tt
-Paraplegia accompanied by uncontrolled spasticity
of such severity that rest and immobilisation are not
possible
-Severe paraplegia of rapid onset,paraplegia in
flexion,flaccid paraplegia,complete sensory or motor loss
for > 6 months.
• Relative Indication :-Recurrent paraplegia even with paraplegia
that would cause no concern in first attack
-Paraplegia with onset in old age
-Painful paraplegia
-complications such as UTI and stones
• Rare Indications:-Post. Spinal disease,spinal tumour
syndrome,severe paralysis from cervical
disease,severe cauda equina paralysis
Surgeries for Pott’s Paraplegia
1. Anterio-lateral decompression (MC)-Spine is opened
up from its lateral side & access is made to the front
and side of the cord.The cord is laid free from
granulation tissue,caseous material,bony spur or
sequestrum
2. Costo-transversectomy-Removal of 2 inches of
rib&transverse processpus comes out.
3. Radical debridement and arthrodesis(Hongkong
operation)
4. Laminectomy-Indicated in spinal tumour syndrome and
paraplegia resulted from post. spinal disease.
Cervical spine: Anterior decompression is preffered.
Paraplegia in adults,sudden onset,with sphincter