May 30, 2024

As per the scoliosis research society (SRS), scoliosis is defined as an abnormal lateral curvature of the spine measuring more than 10° on the radiograph. However, if the curvature is less than 10° then it is called spinal asymmetry.

Classifications of Scoliosis

  1. Idiopathic
    1. Infantile
    2. Juvenile
    3. Adolescent
  2. Neuromuscular
    1. Neurogenic
      1. UMN type
      2. LMN type
    2. Myogenic
  3. Congenital
    1. Failure of formation
    2. Failure of segmentation
    3. Combination
  4. Degenerative
    1. De-novo degeneration
    2. Adolescent deformity of adult
  5. Scoliosis in skeletal dysplasias
  6. Syndromic
  7. Dysplastic
    1. Neurofibromatosis
      1. Dystrophic
      2. Nondystrophic
  8. Others


SRS Classification:

  • Infantile (Birth- 3 years)
  • Juvenile (3- 10 years)
  • Adolescent (10 years – Skeletal maturity)

Dickson and Archer

  • Early-onset scoliosis (<5 years)
  • Late-onset scoliosis (> 5 Years)

Lungs alveoli increases from 20 million at birth to 250 million at 4 years (lungs development completed by 8 years)

Average growth velocity of the spine (>2 cm/yr)

Thoracic volume (5 %) at birth to 30% at 5 years (600 %)

So, scoliosis present before 5 years has significant Pulmo and CVS side effects

Pathoanatomy of idiopathic scoliosis

1. Intra-uterine packing disorder

2. Environmental factors (Sleeping position: better in prone position as it decompress spine)

Clinical features:

Infantile thoracic

  • Diagnosis in 1st 6 months
  • Most have a left-sided thoracic curve (infants)
  • In juvenile: Right-sided thoracic curve
  • They are associated with neural axis abnormalities ( around 20%)
  • 85% of ITS will resolve spontaneously and self-limiting
Idiopathic scoliosis
  • 60% of people are male
  • 90% convex= left-sided curvature
  • Ipsilateral : plagiocephaly (flat head)
  • Resolving / Progressive : more severe
Thoracic, lumbar and thoracolumbar scoliosis

Adolescent thoracic:

  • 90 % of the population are female
  • 90 % convex to Right curvature
  • Rib rotation exaggerates deformity
  • ( 50 % develop curve > 70 °)


  • Female: common
  • Slightly convex to Right common
  • Midway between adolescent thoracic and lumber


  • Female: common
  • Convex to left is the most common
  • Hip prominent ( no rib to accentuate deformity), So not noticed early

2 Broad types of scoliosis

Deformity is secondaryNon- correctable deformity
Condition outside spine: Short leg, FFD hip due to pelvic tilt When the patient sits canceling LLD=>Curve disappearsThe essential component is vertebral rotation Spinous process tilt towards concavity of curve In thoracic=>ribs in convex side become prominent==>RIB HUMP
Sometimes muscle spasms d/t PIVD cause scoliosis=>skew back (Sciatic Scoliosis)Secondary curves always develop to counterbalance primary deformity but with time secondary curves become fixed

Adams test: The prominence of scoliosis becomes more prominent when the patients bend forward.

Imaging of Scoliosis


1. Postero-anterior

2. Lateral

In Postero-anterior

  • Vertebrae towards the apex of the curve appear to be asymmetrical
  • Spinous process deviated towards concavity

Upper and lower level of vertebrae: (end of the curve)

The level where vertebrae start to angle away from the curve

Cobb's angle

UU: Upper border of uppermost vertebrae

LL: Lower border of lowermost vertebrae

Skeletal Maturity- RISSER’S SIGN

Curves often progress most during the period of rapid skeletal growth and maturation

Iliac apophysis starts shortly after puberty, ossification extends medially and when the iliac crest completely ossified: Scoliosis is minimal

Risser's sign

Stage 0: where the apophysis has not appeared

Stage 5: where the apophysis has fused to iliac crest

Treatment of scoliosis

Aims of treatments:

1. To prevent a mild deformity from severe

2. Correct existing deformity i.e. unacceptable to the patient

Non-Surgical treatment:

Observation for

  1. Curve < 20 ° in skeletally immature persons are examined every 6 months
  2. Curve < 20 ° in skeletally mature person requires no further evaluation
  3. Curve > 20 ° in skeletally immature person should be examined 3-4 monthly. Orthotic treatment if curves >25 °
  4. Curve >30-40 ° in skeletally mature person do not require treatment==>radiographic evaluation every 2-3 years

1. Exercises

No effect on a curve but helps to maintain the tone of muscle

2. Traction

  • Stretch contracted structure before OT
    • Skeletal/ Non- skeletal traction can be used

3. Electric stimulation

4. Orthotic treatments

          More than 20 hr/day (23hr daily)

          1. Boston brace (TLSO): most effective

          2. Milwaukee brace

          3. Charleston brace

Complications of bracing:

1. Discomfort and rejection due to poor appearances

2. Skin breakdown

3. Excessive sweating

4. Allergic skin reaction

5. Increase GI pressure, GE reflux

6. Spontaneous Sternum #

Curves response best to bracing:

  1. Curves < 40°
  2. Less severe lumbar hyperlordosis
  3. Curve with thoracic lordosis
  4. Hyperkyphosis
  5. Risers curve is (0)

The brace acts by de-rotating the spine using the rib or transverse process as a lever

Lateral forces in braces are Primary corrective forces.

Surgical treatment:

Indications for surgical treatments are:

  • Curve >50 ° in the mature patient
  • Curve > 10 ° with marked rotation
  • Double major curve > 30 °

The most common form of surgery in idiopathic scoliosis is Segmental instrumentation with a multi-back system

During the correction, spinal cord injury may occur d/t cord traction and column lengthening

Spinal column electrophysiological monitoring should be performed both somatosensory/ motor-evoked potential monitoring

If not available => the Wake Up test

Anesthesia is reduced to bring patients to semi-awake state and patient instructed to move their feet, if the sign of cord compromise: the instrumentation is removed and reapplied with a lesser degree of correction.

Methods of treatments:

  • Distraction Techniques:
    • Rarely used
    • Spinal instrumentation and spinal cord monitoring have been developed
    • Methods:
      • Halo-pelvic distraction
      • Halo-femoral distraction
    • Indications:
      • Kyphosis
      • Rigid scoliosis >100 °
      • Salvage procedure following failed spinal surgery
      • Unstable spine d/t laminectomy
  • Spinal Fusion
    • Indications:
      • Too late for Milwaukee brace, >15 years, >50 ° curve
      • Failure to respond to Milwaukee brace
      • Curve >60 °
      • Pain in adults
      • Paralytic and congenital scoliosis
    • Methods:
      • Anterior fusion
      • Posterior fusion

Unfavorable Prognostic Signs in Scoliosis

  • Congenital/ juvenile/ Paralytic
  • >20-40 ° curve
  • Thoracic curve
  • 2-4 degrees of rotation
  • Risser’s sign 0 / immature
  • Female
  • Pre-menarchal
  • Osteoporosis
  • Single short curve
  • Previous discectomy, laminectomy, etc

Complications of Surgery:

  • Neurological compromise (<1 %)
  • Pseudarthrosis (2% cases)
  • Implant failure