Scoliosis

 According to the Scoliosis Research Society (SRS), scoliosis is a lateral curvature of the spine that measures greater than 10 degrees on x-ray. With scoliosis, there is also structural changes causing wedging and rotation of the vertebra. This creates a 3-dimensional deformity with forward, sideways and rotational movement of the vertebra. The rotation of the vertebra also produces the rib cage and torso asymmetries.

Scoliosis affects 2-3% of the population, or an estimated 6 million people in the U.S. More than 80% have a type called idiopathic, as its cause is unknown.

 
Abnormal spinal curvatures can be affected by an unknown trigger which creates asymmetric loading on the spine. Subsequently this may then lead to a vicious cycle of progressive spinal deformity. 

Idiopathic

This is the most common form of scoliosis, and it is classified depending on the age in which it develops. Idiopathic scoliosis occurs in both girls and boys, however, as children enter adolescence, scoliosis in girls is five to eight times more likely to increase in size and require treatment. Progression is most common during the growing years. Severe curves may however, progress during adulthood. 

Congenital

Present since birth and starts when the spine forms prior to birth. This occurs from a structural deformity of the spine or individual vertebrae.
 

Neuro-muscular

Due to neurological changes i.e cerebral palsy or Arnold Chiari malformation/syrinx
 

Syndromic

Myopathic conditions i.e muscular dystrophy or polio, connective tissue disease i.e. Marfans or Ehlers-Danlos syndrome or genetic syndromes

Adult idiopathic

Occurs from a pre-existing scoliosis, usually from adolescence. May be combined with degenerative changes or imbalances.
 

Adult degenerative

Is adult onset, or de novo scoliosis. This occurs due to degenerative changes of the joints and discs in the spine.
 

Secondary Scoliosis 

Can be either neuro-muscular or congenital

When observed from the side, the normal shape of the thoracic spine has 26-46 degrees of roundedness, called kyphosis.  If there is an excessive amount of this round back, i.e >50 degrees, it is called hyperkyphosis and if it is developmental, can be classified as either postural or structural. 

Postural kyphosis 

This type of kyphosis is flexible and can be improved when patient is asked to stand straight. In postural kyphosis there is no abnormality in the vertebra shape.

Structural kyphosis

This may occur with other spinal problems, ie. healed vertebrae fractures, rheumatoid arthritis, osteoporosis. If it occurs during growth, i.e adolescence,  it is called Scheuermann's kyphosis and the spine is more rigid. There is an abnormal wedging of the vertebra shape as the front sections of the vertebrae grow slower than the back sections, which creates a more sharp, angled kyphosis. 

Congenital kyphosis

Similar to scoliosis, congenital kyphosis is present at birth.