Minor variations in the anatomy of the vertebral column are common. These deformities arise mainly within the Lumbar and Sacral regions and are of little clinical importance. The main conditions in this group include: 

  • Deficient lowest rib
  • Sacralisation of the fifth lumbar vertebra
  • Lumbarisation of the first sacral vertebra
  • Hypertrophy of the fifth lumbar transverse process (can be bilateral or unilateral)


The remainder of the deformities of the spine are of clinical significance. They are classified depending on the region of the spine affected and the plane in which an excessive convexity is formed. The three terms used to denote a deformity are: 


  1. Scoliosis
  2. Kyphosis
  3. Lordosis 


These terms are used to describe the normal curvature of the spine; however, when altered beyond the normal they are also used to describe the resultant deformities.


Scoliosis refers to lateral curvature of the spine. The deformity can be classified into two main groups depending on the underlying pathogenesis:


  1. Structural Scoliosis
  2. Postural Scoliosis



Structural Scoliosis

-          Involves bony changes and is often accompanied by vertebral rotation

-          Deformity is fixed and does not disappear on postural change

-          Secondary curves develop to counteract the primary curves

-          Involves three main types:


1.       Infantile Scoliosis

2.       Idiopathic Structural Scoliosis

3.       Secondary Structural Scoliosis



Infantile scoliosis

  • Presents in first 12 months of life as simple curvature
  • 90% are convex to the left
  • 60% males
  • Cause unknown
  • Associated with ipsilateral plagiocephaly
  • Can be either resolving or progressive


Idiopathic Structural Scoliosis

  • Commonest form
  • Presents in childhood/adolescence e.g 10-12 years
  • Deformity increases progressively until skeletal growth finishes
  • Can affect any region of the thoraco-lumbar spine
  • Often primary structural curve has secondary compensatory curves above and below
  • Accompanied by rotation of vertebra along a vertical axis
  • Vertebral bodies rotate towards convexity and spinous processes rotate away from the convexity
  • 90% convex to the right
  • 90% females
  • 50% develop curves greater than 70º



  • Assessment of prognosis made on age of onset, site and severity of the curve
  • Severity of curve deduced by assessing the Cobb angle
  • Cobb angle = The angle between the uppermost and lowermost vertebra of the primary curvature seen on an erect AP radiograph of the spine
  • Early onset of thoracic scoliosis with a Cobb angle greater than 45º carries a poor prognosis


Active treatment required

  • Period of observation may be needed before deciding on management course
  • Patient examined, photographed and x-rayed at 4 month intervals to check curve progression




  • Have no effect on the curvature
  • Maintain mobility
  • Useful adjunct to operative treatment



  • All progressive curves between 20º and 40º
  • Well balanced double curves
  • Younger patients who ultimately require operative intervention but need curve held stationary until they reach adolescence
  • After spinal fusion to prevent recurrence
  • Two main braces used include the Milwaukee brace and the Boston brace



  • Indicated if curve > 40º
  • Number of techniques used
  • Based on the principal of reducing the curve
  • Full correction rarely achieved
  • Can result in neurological complications


Boston Brace

Secondary Structural Scoliosis

  • Deformity secondary to underlying abnormality
  • Three most common abnormalities causing the scoliosis are:


    1. Congenital abnormalities e.g. Hemivertebra – Only one half of vertebra formed laterally. Affected vertebral body is wedged shaped with the spine angled laterally at the area of the defect. 
    2. Poliomyelitis – ‘Paralytic Scoliosis’ deformity is secondary to unequal pull of the paraspinal muscles. 
    3. Neurofibromatosis


      • Pattern of presentation is determined by the underlying cause
      • Long standing abnormalities may result in neurological complications
      • If spinal cord compromised may result in paralysis below the level of the defect
      • Management is the same as that for Idiopathic Scoliosis



      Postural Scoliosis

      • Deformity is secondary to a pathology outside the spine itself
      • Conditions causing leg asymmetry such as a short leg or pelvic tilt will see a resolution of the deformity when the patient sits (as the asymmetry is cancelled)
      • Local muscle spasm of the para-spinal muscles may also result in scoliotic deformities
      • Involves two main types:


      1.       Compensatory Scoliosis

      2.       Sciatic Scoliosis



      Compensatory Scoliosis

      • Cause of lumbar scoliosis
      • Compensation is for a lateral tilt in the pelvis secondary to e.g. unequal length of lower limbs or fixed abduction/adduction deformity of hip 
      • Lumbar spine is curved by the same angle of pelvic tilt in order to keep trunk upright
      • Scoliosis will disappear when pelvic tilt is corrected
      • If un treated for long duration, deformity may become fixed


      Sciatic Scoliosis

      • Temporary scoliosis secondary to protective movement of spinal muscles
      • Generally due to painful prolapsed disc which is impinging spinal nerve roots
      • Results in lumbar deformity
      • Associated with severe back pain ± sciatica  made worse on spinal movement
      • Deformity poorly compensated therefore trunk tilted to one side
      • No rotation of vertebra



      Kyphosis describes the rounding of the dorsal spine. In the thoracic region an exaggeration of the normal kyphosis results in a marked curvature. Any reduction in the normal lordosis of the cervical or lumbar regions constitutes cervical/lumbar kyphosis. A Kyphos is a sharp posterior angulation secondary to localised collapse of vertebra.


      Kyphosis results from a number of underlying disorders of the spine:


      1. Spinal TB (Pott’s Disease)
      2. Wedge fracture of vertebral body
      3. Scheuermann’s Kyphosis
      4. Calvé’s Vertebral Compression
      5. Ankylosing Spondylitis
      6. Osteoporosis
      7. Spinal tumours 



      Spinal TB

      • Infection originates at anterior aspect of vertebral body
      • Disc involved at early stage
      • Anterior collapse of affected vertebrae results in angular kyphosis
      • Mainly affects young adults
      • Presents with painful, stiff back with kyphotic changes
      • All spinal movements are restricted
      • Abscess may form = mass in flank, iliac fossa or thigh
      • Pott’s paraplegia = signs of spinal cord or nerve root compression
      • Narrowing of intervertebral space early on plain radiograph
      • Later there is loss of bone at the anterior margin, resulting in wedge deformity on plain radiograph
      • Psoas abscess shadow also seen on imaging


      Scheuermann’s Kyphosis

      • Also known as Adolescent vertebral osteochondritis
      • Intrusion of part of the vertebral disc into the vertebral end plate across many levels
      • Mainly affects thoracic spine
      • Due to developmental disturbance of vertebral ring epiphyses
      • Mainly anterior aspect of vertebrae affected
      • Intervertebral disc becomes narrowed anteriorly
      • Vertebral bodies become wedged shaped
      • Usually 13-16 years of age
      • > in males
      • Present with pain in spine, and rounding of the back
      • Plain radiograph in active phase shows deep notches at anterior corners of affected vertebra with irregular shaped ring epiphyses and slight joint space narrowing
      • Often self limiting course of disease therefore treatment often not required
      • Some patients may benefit from bracing or active exercises
      • Severe cases may require surgical correction


      Calvé’s Vertebral Compression

      • Due to changes in central bony nucleus of vertebral body
      • Affects single vertebra mainly in the thoracic region
      • Rare condition caused by eosinophilic granuloma
      • Bony nucleus of vertebral body becomes soft and body develops into a thin slice
      • Vertebra above and below unaffected
      • Affects children aged 2-10 years
      • Presents with pain in thoracic spine with localised kyphosis
      • Plain radiograph shows marked flattening of single vertebral body with increased radiodensity



      • Lordosis describes the normal ventral curvature of the lumbar spine
      • Intrinsic disorders of the spinal column rarely cause lordosis
      • Exaggeration of the normal lumbar lordosis is generally a result of postural deformity due to a combination of lax spinal muscles and a bulky abdomen
      • Excess lordosis may also be due to a compensatory mechanism for other deformities surrounding the lumbar spine including:


      1. Kyphosis above or below lumbar spine
      2. Fixed flexion deformity of the hips




      Hamblen D.L., Simpson A.H.R.W. Adam’s outline of orthopaedics. 14th ed. pp 213-240. Churchill Livingstone, 2010.


      Solomon L., Warwick D., Nayagam S. Apley’s concise system of orthopaedics and fractures. 3rd ed. 185-199. Hodder Arnold, 2005.


      Collier J., Longmore M., Turmezei T., Mafi A.R. Oxford Handbook of Clinical Specialties. 8th ed. pp 672-673. Oxford University Press, 2008.


      http://www.graphicshunt.com/health/images/scoliosis-1434.htm - Accessed 4/3/12


      http://www.orthoticsprostheticsne.com/home/images/stories/soft-boston-scoliosis-brace.jpg - Accessed 4/3/12


      http://dccdn.de/pictures.doccheck.com/photos/0/e/45a8a1c5e9bd6b4_m.jpg- Accessed 4/3/12


      http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/9499.jpg- Accessed 4/3/12



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