Spinal Disorders: Scoliosis and Spinal Deformity

Scoliosis is the most common spinal deformity and is described as an abnormal side-to-side spinal curve.  Scoliosis can develop in the thoracic (mid-back) and lumbar (low back) spine.  When progressive, scoliosis may cause the spine to turn or rotate.  Rotational forces can pull the ribs and further distort the shape of the spine, cause one side of the body to be a different height, and create a rib hump on the back.  Sometimes, scoliosis is caused by muscle problems, does not involve spinal rotation, and is almost always reversible.

Left: Normal spine    –    Right: Scoliotic curves

Scoliosis can cause:

  • One shoulder or hip to be higher than the other
  • One leg longer than the other
  • Head appears not centered over the body
  • Hemlines and trousers hang unevenly
  • Shoulder blade / rib cage prominence when bending forward at the waist
  • Visible curvature of the spine
  • Back pain (severe scoliosis)
  • Shortness of breath (severe scoliosis)

About Scoliosis

There are many types of scoliosis.  Sometimes the cause is known.  When the cause of the disorder is unknown, it is termed idiopathic scoliosis.  There are 3 types of idiopathic scoliosis:

  • Congenital (at birth) and Infantile: ages 3 years or younger
  • Juvenile: ages 4 to 10 years
  • Adolescent: ages 10 to 18 years


  • Adolescent idiopathic scoliosis is more common
  • Girls are affected more than boys
  • Heredity play a part; it can run in families

Scoliosis affects adults too.  Causes of adult scoliosis include:

  • Untreated congenital (at birth) or childhood scoliosis
  • Spinal degeneration (i.e. degenerative disc disease, osteoarthritis, osteoporosis)
  • Neuromuscular problems (i.e. muscular dystrophy, cerebral palsy, Marfan’s disease)

Known Causes

The causes of scoliosis fall into one of three categories: functional, neuromuscular, or degenerative.

Functional scoliosis is also termed nonstructural scoliosis because poor posture, a short leg, and/or the back muscles cause the spine to curve abnormally.  This type of scoliosis is almost always reversible. 

Neuromuscular scoliosis can be caused by cerebral palsy, Marfan’s disease, muscular dystrophy, muscle atrophy, polio, spina bifida, or spinal cord injury.  Abnormal spinal curvature may worsen during growth spurts and lead to weak trunk muscles making it difficult to sit upright, stand, or walk.

Degenerative scoliosisaffects adults and develops secondary to a spinal condition such as bone spurs, degenerative disc disease, osteoarthritis, osteoporosis, spinal fracture, or weakening of soft tissues such as the spine’s ligaments.

Curve Types

A component of a scoliotic curve is called a compensatory curve or counter curve.  This means to compensate for the major curve, a curve develops above or below the major curve.  The compensatory curve is usually less severe than the major curve.  This is how the body tries to deal with maintaining balance.  For example, if the major curve is to the left, the compensatory curve is to the right.