An Introduction to Scoliosis and Its Causes
Scoliosis is a musculoskeletal disorder in which there is a sideways curvature of the spine, or backbone. In most people (80 to 85 percent of cases), the cause of scoliosis is unknown. This type of scoliosis is called idiopathic scoliosis.
Before concluding that a person has idiopathic scoliosis, the doctor will look for other possible causes. These are generally classified into one of two types:
- Nonstructural (functional) scoliosis
- Structural scoliosis.
Different causes are common within each of these different types of scoliosis.
Nonstructural (Functional) Causes of Scoliosis
Nonstructural scoliosis is when the spine is structurally normal but appears curved because of another cause.
This type of scoliosis is most often caused by an underlying condition, such as:
- A difference in leg length
- Muscle spasms
- Inflammatory conditions, such as appendicitis.
Doctors treat nonstructural scoliosis by correcting the underlying problem.
(Click Scoliosis Treatments for more information about treatment options for this condition.)
Causes of Structural Scoliosis
In structural scoliosis, the spine has a fixed curve that is structurally abnormal.
The causes for this type of scoliosis include:
- Neuromuscular diseases (such as cerebral palsy, poliomyelitis, or muscular dystrophy)
- Birth defects (such as hemivertebra)
- Injury
- Certain infections
- Tumors (such as those caused by neurofibromatosis)
- Metabolic diseases
- Connective tissue disorders
- Rheumatic diseases
- Unknown factors (idiopathic scoliosis).
Structural scoliosis can be one part of a syndrome or disease. An example of this is
Marfan syndrome, which is an inherited connective tissue disorder. In other cases, structural scoliosis occurs by itself.