Scoliosis and Its Types

Scoliosis is defined as a lateral abnormal curvature of the spine. It could be classified by may parameters but broadly speaking, there are two types – nonstructural and structural

Types of Scoliosis

Nonstructural

In this type, the spine has a lateral curvature but there is no structural abnormality in the spine. The curvature is in response to habit or a disease process.

The spine is structurally normal with a lateral curvature, no spinal rotation, and no truncal asymmetry.

Types of nonstructural scoliosis:

• Postural
  • Prolonged use of a wrong posture. Resolves on lying down.
• Compensatory
  • In leg-length discrepancy
  • Usually goes off on sitting.
• Sciatic
  • This curve results from trying to avoid pain from an irritated sciatic nerve
• Inflammatory
  • Caused by an infective process such as an appendicitis. The body curves in response to the disease or abdominal muscle spasm.
• Hysterical
• Underlying psychological component

Structural

It is the one that involves both a lateral curvature and rotation of the vertebrae. Most common type is idiopathic. All other types form the group non-idiopathic.

Idiopathic

It is the most common type and is classified on the basis of the age when scoliosis develops. For example in a person less than 3 years old, it is called infantile idiopathic scoliosis.

Neuromuscular

It is caused by an abnormal development of the bones of the spine for example hemivertebra or due to other paralytic disorders.

Degenerative

Degenerative scoliosis occurs in older adults. Degenerative changes may lead to the weakening of the normal ligaments and other soft tissues of the spine. In presence of arthritic changes abnormal curvature may result

Miscellaneous

Any pathology in the spine like spine tumors may cause people to lean to the opposite side to reduce discomfort. Prolonged posturing may lead to scoliosis.

Here is the list of causes of nonidiopathic structural scoliosis. [This group includes all types except idiopathic]

• • Cerebral palsy
  • Spinocerebellar degeneration
  • Friedreich’s ataxia
  • Hereditary Motor and Sensory Neuropathies
  • Trauma
  • Spinal tumor
  • Syringomyelia
  • Poliomyelitis
  • Spinal muscular atrophy I-IV
• Muscular dystrophies
  • Duchenne and Becker’s
  • Limb-girdle
  • Facio-scapulo-humeral

• Myotonia dystrophica
• Achondroplasia and hypochondroplasia
• Spondylolisthesis
• Mesenchymal disorders
  • Marfan’s syndrome
  • Ehlers-Danlos syndrome
• Spina bifida
• Neurofibromatosis
• Rheumatoid disease
• Tumors
  • Osteoid osteoma
  • Osteoblastoma
  • Eosinophilic granuloma
  • Intraspinal tumors like  ependymoma, astrocytoma, epidermoid cyst