Tuberculosis Spine

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2259
Tuberculosis-Spine
Tuberculosis-Spine AIIMS PGI AIPGMEE
  • Tuberculosis of the spine (Pott’s disease) (crohn’s disease)
    • spine is the commonest site of bone and joint tuberculosis (MCQ)
    • dorso-lumbar region being the one affected most frequently. (MCQ)
    • Surgical anatomy
      • Development of a vertebra
        • A vertebra develops from the sclerotomes which lie on either side of the notochord.
        • Embyologic basis of Paradiscal tuberculosis of the spine (MCQ)
          • The lower-half of one vertebra and upper-half of the one below it, along with the intervening disc develop from each pair of sclerotomes and have a common blood supply.
      • Cord-segment localisation:Vertebral level-landmarks (MCQ)
        • Most prominent spinous process at the              base of the neck –C 7
        • At the level of the spine of the scapula – D3
        • At the level of lower angle of the scapulaD7               s
        • Floating rib –D12
        • At the level of the iliac crestsL4
        • At the level of the post. sup. iliac spine –S2
  • Relationship between spinal and cord segments (MCQ)
    • Cervical vertebrae -Add 1 to vertebral level
    • Upper dorsal vertebrae– Add 2 to vertebral level
    • Lower dorsal vertebrae– Add 3 to vertebral level
    • At D 10 -All dorsal segments over
    • At D12. – All lumbar segments over
    • At L1– All sacral segments over
    • Below L1 -Cauda equina
  • Pathology
    • TB of the spine is always secondary
    • The bacteria reach the spine via the haematogenous route, from the lungs or lymph nodes. (MCQ)
    • It spreads via the para-vertebral plexus of veins i.e., Batson’s plexus,
    • Types of vertebral tuberculosis:
      • Paradiscal
        • commonest type. (MCQ)
        • the contiguous areas of two adjacent vertebrae along with the intervening disc are affected.
      • Central
        • body of a single vertebra is affected.
        • This leads to early collapse of the weakened vertebra.
        • ollapse may be a ‘wedging’ or ‘concertina’ collapse
        • “wedging is commoner. (MCQ)
      • Anterior
        • infection is localised to the anterior part of the vertebral body.
        • The infection spreads up and down under the anterior longitudinal ligament.
      • Posterior
        • posterior complex of the vertebra i.e., the pedicle, lamina, spinous process and transverse process are affected.
    • Why does wedging occurs early, severe in lesions of the dorsal spine. (MCQ)
      • This is because, in the dorsal spine the line of weight bearing passes anterior to the vertebra, so that the anterior part of the weakened vertebra is more compressed than the posterior, resulting in wedging.
      • In the cervical and lumbar spines, because of their lordotic curvature (round forwards), wedging is less.
    • Cold abscess:
      • a collection of pus and tubercular debris from a diseased vertebra.
      • It is called a cold abscess because it is not associated with the usual signs of inflammation – found with a pyogenic abscess.
  • Clinical features
    • Back pain is most common presenting symptom (MCQ)
    • Stiffness:
      • It is a very early symptom in TB of the spine. (MCQ)
      • It is a protective mechanism of the body, wherein the paravertebral muscles go into spasm to prevent movement at the affected vertebra.
    • Cold abscess:
    • Paraplegia
    • Deformity:
      • Attention to TB of the spine may be attracted, especially in children, by a gradually  increasing  prominence  of the spine – a gibbus.
    • Constitutional symptoms
  • Physical examination
    • Gait:
      • A patient with TB of the spine walks with short steps in order to avoid jerking the spine. (MCQ)
      • He may take time and may be very cautious while attempting to lie on the examination couch.
      • In TB of the cervical spine, the patient often supports his head with both hands under the chin and twists his whole body in order to look sideways.
    • Attitude and deformity:
      • A patient with TB of the cervical spine has a stiff, straight neck.
      • In dorsal spine TB, part of the spine becomes prominent (gibbus or kyphus*).
      • Significant deformity is generally absent in lumbar spine tuberculosis; there may just be loss of lumbar lordosis.
    • Para-vertebral swelling:
      • A superficial cold abscess may present as fullness or swelling on the back, along the chest wall or anteriorly.
      • It is easy to diagnose because of its fluctuant nature
    • There are three types of kyphotic deformities:
      • Knuckle    – prominence of one spinous process
      • Gibbus     – prominence of two or three spinous processes
      • Kyphusdiffuse rounding of the vertebral column
  • Radiological investigations
    • X-ray examination: important radiological features.
      • Reduction of disc space: (MCQ)
        • This is the earliest signin the commoner, paradiscal type of tuberculosis (MCQ)
        • A lateral X-ray is better for evaluation of disc space. (MCQ)
        • Differential diagnosis : secondaries in the spine, the disc space is “well preserved” (MCQ)
      • Destruction of the vertebral body:
        • In early stages, the   contiguous   margins   of  the   affected vertebrae may be eroded
        • diseased, weakened vertebra may undergo wedging
        • In late stages, a significant part or -whole of the vertebral body may be destroyed leading to angular kyphotic deformity
      • Evidence of cold abscess
      • Abscesses seen on X-rays:
        • Para-vertebral abscess:
          • A para-vertebral soft tissue shadow corresponding to the site of the affected vertebra in AP view indicates a para-vertebral abscess.
          • Types
            • a fusiform paravertebral abscess
              • bird nest abscess – an abscess whose length is greater than its width (MCQ)
            • Globular or tense abscess (MCQ)
              • an abscess whose width is greater than the length
              • indicates pus under pressure
              • commonly associated with paraplegia. (MCQ)
        • Widened mediastinum:
          • An abscess from the dorsal spine may present as widened mediastinum on AP X-ray. (MCQ)
        • Retro-pharyngeal abscess:
          • In cervical spine TB, a retro-pharyngeal abscess may be seen on a lateral X-ray.
          • Normally, soft tissue shadow in front of the C3 vertebral body is 4 mm thick; an increase in its thickness indicates a retro-pharyngeal abscess (MCQ)
        • Psoas abscess:
          • In dorso-lumbar and lumbar tuberculosis, psoas shadow on an X-ray of the abdomen may show a bulge.
      • Rarefaction:
        • There is diffuse rarefaction of the vertebrae above and below the lesion.
      • Unusual signs:
        • In tuberculosis involving the posterior complex, there may be erosion of the posterior elements of pedicle, lamina etc.
          • These are better visible on oblique X-rays of the spine.
        • Aneurysmal sign(MCQ)
          • Anterior type of vertebral tuberculosis may show erosion of the anterior part of the body,
          • It is similar to what is  seen sometimes in cases with aneurysm of aorta
        • There may be lytic lesions in the ribs in the vicinity of the affected vertebra.
      • Signs of healing:
        • lesions are replaced by sclerotic bone.
        • adjacent vertebrae undergo bony fusion
    • CT scan:
      • very useful investigation in cases presenting as ‘spinal tumour syndrome’, where there may be no signs on plain X-rays (MCQ)
    • MRI  – investigation of choice to evaluate the type and extent of compression of the cord (MCQ)
    • Myelography: Indications(MCQ)
      • cases presenting with ‘spinal tumour syndrome
      • when the clinical level of neurological deficit does not correspond to the radiological level of the lesion.
  • Complications
    • Cold abscess
      • Most common complication of TB of the spine(MCQ)
    • Neurological compression
      • occurs most commonly in tuberculosis of the dorsal spine (MCQ)
        • Reason : Spinal canal is narrowest in this part,and even a small compromise can lead to a neurological deficit.
      • Causes of compression
        • Inflammatory oedema
        • Extradural pus and granulation tissue:
          • commonest cause of compression on neural structures.
        • Sequestra
        • Internal ‘gibbus’:
          • Angulation of the diseased spine may lead to formation of the bony ridge  on the anterior wall of the spinal canal – called the internal gibbus
        • Infarction of the spinal cord:
          • results from, blockage of the anterior spinal artery
        • Extradural granuloma
          • presents with a clinical picture of a spinal tumour – the so-called ‘Spinal tumour syndrome’.
  • Pott’s paraplegia
    • Types
      • Early  onset   paraplegia 
        • Paraplegia occurring during the active phase of the disease
        • usually occurs within two years of onset of the disease.
      • Late   onset   paraplegia
        • Paraplegia occurring several years after the disease has become quiescent
        • Usually at least two years after the onset of disease.

.

  • Clinical features
    • Onset of paraplegia is gradual in most cases, but in some it is sudden.
    • Tubercular paraplegia is usually spastic to start with (MCQ)
    • Clonus (ankle or patellar) is the most prominent early sign (MCQ)
    • Paralysis may pass with varying rapidity, through the following stages:
      • Muscle    weakness, spasticity and incoordination
        • Occur due to pressure on the corticospinal tracts which are placed anteriorly in the cord and are probably more sensitive to pressure.
      • Paraplegia in extension: (MCQ)
        • Tone of the muscles is   increased
        • due to  absence of  normal corticospinal inhibition, resulting in paraplegia in extension.
      • Paraplegia in flexion (MCQ)
      • Complete flaccid paraplegia
  • Potts’ paraplegia –  four grades
    • Grade I:
      • Patient is unaware of the neural deficit
      • physician detects Babinski positive and ankle or patellar clonus on clinical examination.
    • Grade II:
      • Patient presents with complaints of clumsiness, in-coordination or spasticity while walking, but manages to walk with or without support.
    • Grade III:
      • Patient is not able to walk because of severe weakness.
      • On examination, he has paraplegia in extension.
      • There may be partial loss of sensation.
    • Grade IV:
      • Patient is unable to walk
      • has paraplegia in flexion with severe muscle spasm
      • There is near complete loss of sensation with sphincter disturbances.
  • MRI is the investigation of choice, wherever available. (MCQ)
  • Treatment
    • Indications for surgery
      • Absolute indications(MCQ)
        • Paraplegia occurring during usual conservative treatment.
        • Paraplegia getting worse or remaining stationary despite adequate conservative treatment.
        • Severe paraplegia  with  rapid onsetmay indicate severe pressure from a mechanical accident or abscess.
        • Any severe paraplegia such as
          • paraplegia in flexion
          • motor or sensory loss for more than six months
          • complete loss of motor power for one month despite adequate conservative treatment.
          • Paraplegia accompanied by uncontrolled spasticityof such severity that reasonable rest and immobilisation are not possible.
      • Relative indications (MCQ)
        • Recurrent paraplegia, even with paralysis that would cause no concern in the first attack.
        • Paraplegia with onset in old age:
          • because of the hazards of recumbency.
        • Painful paraplegia,
          • pain resulting from spasm or root compression.
        • Complications such as urinary tract infection and stones.
      • Rare indications
        • Paraplegia due to posterior spinal disease.
        • Spinal tumour syndrome.
        • Severe paralysis secondary to the cervical disease.
        • Severe cauda equina paralysis.
  • Operative procedures for Pott’s paraplegia:
    • Costo-transversectomy (MCQ)
      • Indications
        • in a child with paraplegia
        • when a tense abscess is visible on X-ray.
    • Antero-lateral decompression (ALD):
      • most commonly performed operation. (MCQ)
      • Lamina or facet joints are not removed, otherwise stability of the spine will be seriously jeopardized.
    • Radical   debridement   and   arthrodesis (Hongkong operation): (MCQ)
      • Advantage of this operation is early healing of the disease and no progress of the kyphosis.
    • Laminectomy –Indications(MCQ)
      • spinal tumour syndrome
      • those where paraplegia has resulted from posterior spinal disease.
    • Surgery for the cervical spine tuberculosis requires a separate technique; anterior decompression is preferable in this area.
  • Prognosis of Pott’s paraplegia depends upon the following factors: (MCQ)
    • Age:
      • Children respond to treatment better than adults.
    • Onset:
      • Acute onset paraplegia has a better prognosis.
    • Duration:
      • Long standing paraplegia has a worse prognosis.
    • Severity:
      • Motor paralysis alone has a good prognosis.
      • Sphincter involvement i.e., urinary or bowel incontinence are bad prognostic indicators.
    • Progress:

Sudden progress of the paraplegia has a bad prognosis.

  • Tuberculosis of the spine (Pott’s disease)
    • spine is the commonest site of bone and joint tuberculosis (MCQ)
    • dorso-lumbar region being the one affected most frequently. (MCQ)
    • Surgical anatomy
      • Development of a vertebra
        • A vertebra develops from the sclerotomes which lie on either side of the notochord.
        • Embyologic basis of Paradiscal tuberculosis of the spine (MCQ)
          • The lower-half of one vertebra and upper-half of the one below it, along with the intervening disc develop from each pair of sclerotomes and have a common blood supply.
      • Cord-segment localisation:Vertebral level-landmarks (MCQ)
        • Most prominent spinous process at the              base of the neck –C 7
        • At the level of the spine of the scapula – D3
        • At the level of lower angle of the scapulaD7               s
        • Floating rib –D12
        • At the level of the iliac crestsL4
        • At the level of the post. sup. iliac spine –S2
  • Relationship between spinal and cord segments (MCQ)
    • Cervical vertebrae -Add 1 to vertebral level
    • Upper dorsal vertebrae– Add 2 to vertebral level
    • Lower dorsal vertebrae– Add 3 to vertebral level
    • At D 10 -All dorsal segments over
    • At D12. – All lumbar segments over
    • At L1– All sacral segments over
    • Below L1 -Cauda equina
  • Pathology
    • TB of the spine is always secondary
    • The bacteria reach the spine via the haematogenous route, from the lungs or lymph nodes. (MCQ)
    • It spreads via the para-vertebral plexus of veins i.e., Batson’s plexus,
    • Types of vertebral tuberculosis:
      • Paradiscal
        • commonest type. (MCQ)
        • the contiguous areas of two adjacent vertebrae along with the intervening disc are affected.
      • Central
        • body of a single vertebra is affected.
        • This leads to early collapse of the weakened vertebra.
        • ollapse may be a ‘wedging’ or ‘concertina’ collapse
        • “wedging is commoner. (MCQ)
      • Anterior
        • infection is localised to the anterior part of the vertebral body.
        • The infection spreads up and down under the anterior longitudinal ligament.
      • Posterior
        • posterior complex of the vertebra i.e., the pedicle, lamina, spinous process and transverse process are affected.
    • Why does wedging occurs early, severe in lesions of the dorsal spine. (MCQ)
      • This is because, in the dorsal spine the line of weight bearing passes anterior to the vertebra, so that the anterior part of the weakened vertebra is more compressed than the posterior, resulting in wedging.
      • In the cervical and lumbar spines, because of their lordotic curvature (round forwards), wedging is less.
    • Cold abscess:
      • a collection of pus and tubercular debris from a diseased vertebra.
      • It is called a cold abscess because it is not associated with the usual signs of inflammation – found with a pyogenic abscess.
  • Clinical features
    • Back pain is most common presenting symptom (MCQ)
    • Stiffness:
      • It is a very early symptom in TB of the spine. (MCQ)
      • It is a protective mechanism of the body, wherein the paravertebral muscles go into spasm to prevent movement at the affected vertebra.
    • Cold abscess:
    • Paraplegia
    • Deformity:
      • Attention to TB of the spine may be attracted, especially in children, by a gradually  increasing  prominence  of the spine – a gibbus.
    • Constitutional symptoms
  • Physical examination
    • Gait:
      • A patient with TB of the spine walks with short steps in order to avoid jerking the spine. (MCQ)
      • He may take time and may be very cautious while attempting to lie on the examination couch.
      • In TB of the cervical spine, the patient often supports his head with both hands under the chin and twists his whole body in order to look sideways.
    • Attitude and deformity:
      • A patient with TB of the cervical spine has a stiff, straight neck.
      • In dorsal spine TB, part of the spine becomes prominent (gibbus or kyphus*).
      • Significant deformity is generally absent in lumbar spine tuberculosis; there may just be loss of lumbar lordosis.
    • Para-vertebral swelling:
      • A superficial cold abscess may present as fullness or swelling on the back, along the chest wall or anteriorly.
      • It is easy to diagnose because of its fluctuant nature
    • There are three types of kyphotic deformities:
      • Knuckle    – prominence of one spinous process
      • Gibbus     – prominence of two or three spinous processes
      • Kyphusdiffuse rounding of the vertebral column
  • Radiological investigations
    • X-ray examination: important radiological features.
      • Reduction of disc space: (MCQ)
        • This is the earliest signin the commoner, paradiscal type of tuberculosis (MCQ)
        • A lateral X-ray is better for evaluation of disc space. (MCQ)
        • Differential diagnosis : secondaries in the spine, the disc space is “well preserved” (MCQ)
      • Destruction of the vertebral body:
        • In early stages, the   contiguous   margins   of  the   affected vertebrae may be eroded
        • diseased, weakened vertebra may undergo wedging
        • In late stages, a significant part or -whole of the vertebral body may be destroyed leading to angular kyphotic deformity
      • Evidence of cold abscess
      • Abscesses seen on X-rays:
        • Para-vertebral abscess:
          • A para-vertebral soft tissue shadow corresponding to the site of the affected vertebra in AP view indicates a para-vertebral abscess.
          • Types
            • a fusiform paravertebral abscess
              • bird nest abscess – an abscess whose length is greater than its width (MCQ)
            • Globular or tense abscess (MCQ)
              • an abscess whose width is greater than the length
              • indicates pus under pressure
              • commonly associated with paraplegia. (MCQ)
        • Widened mediastinum:
          • An abscess from the dorsal spine may present as widened mediastinum on AP X-ray. (MCQ)
        • Retro-pharyngeal abscess:
          • In cervical spine TB, a retro-pharyngeal abscess may be seen on a lateral X-ray.
          • Normally, soft tissue shadow in front of the C3 vertebral body is 4 mm thick; an increase in its thickness indicates a retro-pharyngeal abscess (MCQ)
        • Psoas abscess:
          • In dorso-lumbar and lumbar tuberculosis, psoas shadow on an X-ray of the abdomen may show a bulge.
      • Rarefaction:
        • There is diffuse rarefaction of the vertebrae above and below the lesion.
      • Unusual signs:
        • In tuberculosis involving the posterior complex, there may be erosion of the posterior elements of pedicle, lamina etc.
          • These are better visible on oblique X-rays of the spine.
        • Aneurysmal sign(MCQ)
          • Anterior type of vertebral tuberculosis may show erosion of the anterior part of the body,
          • It is similar to what is  seen sometimes in cases with aneurysm of aorta
        • There may be lytic lesions in the ribs in the vicinity of the affected vertebra.
      • Signs of healing:
        • lesions are replaced by sclerotic bone.
        • adjacent vertebrae undergo bony fusion
    • CT scan:
      • very useful investigation in cases presenting as ‘spinal tumour syndrome’, where there may be no signs on plain X-rays (MCQ)
    • MRI  – investigation of choice to evaluate the type and extent of compression of the cord (MCQ)
    • Myelography: Indications(MCQ)
      • cases presenting with ‘spinal tumour syndrome
      • when the clinical level of neurological deficit does not correspond to the radiological level of the lesion.
  • Complications
    • Cold abscess
      • Most common complication of TB of the spine(MCQ)
    • Neurological compression
      • occurs most commonly in tuberculosis of the dorsal spine (MCQ)
        • Reason : Spinal canal is narrowest in this part,and even a small compromise can lead to a neurological deficit.
      • Causes of compression
        • Inflammatory oedema
        • Extradural pus and granulation tissue:
          • commonest cause of compression on neural structures.
        • Sequestra
        • Internal ‘gibbus’:
          • Angulation of the diseased spine may lead to formation of the bony ridge  on the anterior wall of the spinal canal – called the internal gibbus
        • Infarction of the spinal cord:
          • results from, blockage of the anterior spinal artery
        • Extradural granuloma
          • presents with a clinical picture of a spinal tumour – the so-called ‘Spinal tumour syndrome’.
  • Pott’s paraplegia
    • Types
      • Early  onset   paraplegia 
        • Paraplegia occurring during the active phase of the disease
        • usually occurs within two years of onset of the disease.
      • Late   onset   paraplegia
        • Paraplegia occurring several years after the disease has become quiescent
        • Usually at least two years after the onset of disease.

.

  • Clinical features
    • Onset of paraplegia is gradual in most cases, but in some it is sudden.
    • Tubercular paraplegia is usually spastic to start with (MCQ)
    • Clonus (ankle or patellar) is the most prominent early sign (MCQ)
    • Paralysis may pass with varying rapidity, through the following stages:
      • Muscle    weakness, spasticity and incoordination
        • Occur due to pressure on the corticospinal tracts which are placed anteriorly in the cord and are probably more sensitive to pressure.
      • Paraplegia in extension: (MCQ)
        • Tone of the muscles is   increased
        • due to  absence of  normal corticospinal inhibition, resulting in paraplegia in extension.
      • Paraplegia in flexion (MCQ)
      • Complete flaccid paraplegia
  • Potts’ paraplegia –  four grades
    • Grade I:
      • Patient is unaware of the neural deficit
      • physician detects Babinski positive and ankle or patellar clonus on clinical examination.
    • Grade II:
      • Patient presents with complaints of clumsiness, in-coordination or spasticity while walking, but manages to walk with or without support.
    • Grade III:
      • Patient is not able to walk because of severe weakness.
      • On examination, he has paraplegia in extension.
      • There may be partial loss of sensation.
    • Grade IV:
      • Patient is unable to walk
      • has paraplegia in flexion with severe muscle spasm
      • There is near complete loss of sensation with sphincter disturbances.
  • MRI is the investigation of choice, wherever available. (MCQ)
  • Treatment
    • Indications for surgery
      • Absolute indications(MCQ)
        • Paraplegia occurring during usual conservative treatment.
        • Paraplegia getting worse or remaining stationary despite adequate conservative treatment.
        • Severe paraplegia  with  rapid onsetmay indicate severe pressure from a mechanical accident or abscess.
        • Any severe paraplegia such as
          • paraplegia in flexion
          • motor or sensory loss for more than six months
          • complete loss of motor power for one month despite adequate conservative treatment.
          • Paraplegia accompanied by uncontrolled spasticityof such severity that reasonable rest and immobilisation are not possible.
      • Relative indications (MCQ)
        • Recurrent paraplegia, even with paralysis that would cause no concern in the first attack.
        • Paraplegia with onset in old age:
          • because of the hazards of recumbency.
        • Painful paraplegia,
          • pain resulting from spasm or root compression.
        • Complications such as urinary tract infection and stones.
      • Rare indications
        • Paraplegia due to posterior spinal disease.
        • Spinal tumour syndrome.
        • Severe paralysis secondary to the cervical disease.
        • Severe cauda equina paralysis.
  • Operative procedures for Pott’s paraplegia:
    • Costo-transversectomy (MCQ)
      • Indications
        • in a child with paraplegia
        • when a tense abscess is visible on X-ray.
    • Antero-lateral decompression (ALD):
      • most commonly performed operation. (MCQ)
      • Lamina or facet joints are not removed, otherwise stability of the spine will be seriously jeopardized.
    • Radical   debridement   and   arthrodesis (Hongkong operation): (MCQ)
      • Advantage of this operation is early healing of the disease and no progress of the kyphosis.
    • Laminectomy –Indications(MCQ)
      • spinal tumour syndrome
      • those where paraplegia has resulted from posterior spinal disease.
    • Surgery for the cervical spine tuberculosis requires a separate technique; anterior decompression is preferable in this area.
  • Prognosis of Pott’s paraplegia depends upon the following factors: (MCQ)
    • Age:
      • Children respond to treatment better than adults.
    • Onset:
      • Acute onset paraplegia has a better prognosis.
    • Duration:
      • Long standing paraplegia has a worse prognosis.
    • Severity:
      • Motor paralysis alone has a good prognosis.
      • Sphincter involvement i.e., urinary or bowel incontinence are bad prognostic indicators.
    • Progress:
      • Sudden progress of the paraplegia has a bad prognosis.