Paediatric spinal deformities

from: Archer, Dickson. Curr. Orth. 3:72-6. 1989.

Kyphosis= failure in one plane, Scoliosis= failure in 3 planes (essential deformity is lordosis).

The axis of spinal rotation (determined b the orientation of the facet joints) lies behind the cervical & lumbar curves & in front of the thoracic curve. The centre of gravity lies in front of the whole spine. Therefore lordoses are unstable in forward flexion, tending to rotate. The cervical & lumbar lordoses are protected by the shape of the vertebrae being broader anteriorly & powerful stabilising muscles & ligaments. Thoracic vertebrae are narrower anteriorly & wedged asymmetricaly by aorta. Thus any loss of kyphosis -> rotational buckling.

Spine can be modelled as an elastic cantilever -> Eulers law of column buckling. P_crit = C(EI/L²) where P_crit is the critical load, C is the end conditions, E is the modulus of elasticity, I the cross sectional moment of inertia with respect to the direction of load and plane of buckling and L is the column length. Thus increasing the column length will reduce the critical load at which buckling occurs, as well as altering the cross-sectional shape or material strength which would also affect the critical load. Thus it is clear that taller and heavier individuals, intrinsic vertebral bone weakness or weak extrinsic support reduce the critical buckling load.

In scoliosis the essential deformity is lordosis, with the spinous processes being directed to the concavity of the lateral curve. As rotation progresses the load on the epiphysis on the side of the body which is more anterior increases (Heuter Volkmann law) -> lateral deformation -> rib hump.

Scoliosis= triplanar deformity of lordosis, rotation & lateral wedging of vertebrae.

= Pressure on an epiphysis retards the rate of growth whilst tension increases the rate. Thus the 'leading edge' of a deformity grows more rapidly than the 'trailing edge', increasing the rate of progression.(eg. Scoliosis)

of Spinal Deformities - Scoliosis Research Society:

• Idiopathic scoliosis

  • Early Onset - before 5yrs of age

  • Late onset - after 5yrs of age

• Idiopathic kyphosis

  • Type 1 - classical thoracic Sheuermann's disease

  • Type 2 - 'apprentices spine' - thoracolumbar or lumbar

• Neuromuscular deformities

  • Cerebral palsy

  • Poliomyelitis

  • True NMD

  • Familial dysautonomia

  • Malignant hyperpyrexia

• Deformities associated with Neurofibromatosis

• Mesenchymal deformities

  • Connective tissue disorders

  • Mucopolysaccharidoses

  • Bone Dysplasias

  • Metabolic bone disease

  • Endocrine disorders

• Traumatic

  • vertebral

  • extravertebral

• Infection

  • Pyogenic

  • TB

• Tumours

  • Intradural

  • Extradural

  • Paravertebral

  • Syringomyelia

  • Metastases

• Spondylolisthesis

  • Dysplastic

  • Isthmic

  • Degenerative

  • Traumatic

  • Pathological

• Spinal deformity in adults

  • True adult deformities

  • Adult presenting deformities

Scoliosis Classification (International Scoliosis Society):

• Idiopathic

  • Infantile 

  • Juvenile

  • Adolescent

  • Adult