Everyone's spine has natural curves. These curves round our shoulders and make the lower back curve slightly inward. But some people have spines that also curve from side to side, a common condition called scoliosis. Scoliosis is defined as curvature of the spine greater than 10 degrees, as measured on an X-ray. Anything less is simply due to normal variation. On an X-ray, a spine with scoliosis looks more like an "S" or a "C" than a straight line. Some of the bones in a scoliotic spine also may have rotated slightly, making the person's waist or shoulders appear uneven.
Scoliosis affects approximately 20 million people in North America, about 2 percent of the population, including children and adults. The condition tends to run in families. If someone in a family has scoliosis, the likelihood of another family member having it is much higher — about 20 percent.
As the population ages, adult degenerative scoliosis is becoming more common, with the condition typically developing at between age 50 to 70. The condition can have devastating effects on a person's life in later years.
Treatment in this older population presents particular challenges due to other back conditions, such as osteoporosis. But significant advances — including minimally invasive surgery, new neuro-monitoring techniques and 3-dimensional imaging — allows older patients to receive limited doses of anesthesia and benefit from quicker recovery.
Scoliosis may be divided into five types:
Congenital Scoliosis — Congenital means that a person is "born with" scoliosis. Congenital scoliosis is caused by an abnormality of one or more vertebrae where they fail to form properly. This can be seen on X-ray and directly in the operating room.
Idiopathic Scoliosis — This is the most common form of scoliosis. The name idiopathic means "the cause is unknown." Those with this type of scoliosis are otherwise healthy and normal. The spine shows no abnormality of the bones themselves on X-rays or by looking at it directly in the operating room. Idiopathic scoliosis may involve pain, which is more common in adults with scoliosis.
While the overall incidence is equal in females and males, progressive or severe idiopathic scoliosis is about six to seven times more frequent in females.
Neuromuscular Scoliosis — This type of scoliosis occurs in people who have a disease of the nervous system, such as cerebral palsy.
Postural Scoliosis — Also known as "hysterical scoliosis," postural scoliosis may be a result of pain, as a patient tilts to relieve the pain. It can be reversed by relieving the pain or by having the patient lie flat. X-rays don't show any abnormality of the vertebrae.
Syndromic Scoliosis — This type of scoliosis occurs in people with a syndrome, such as Marfan syndrome or one of the skeletal dysplasias such as achondroplasia.
Progressive, severe scoliosis can produce three major problems:
If the part of the spine in the chest, called the thoracic spine, curves more than 60 degrees, the volume of the chest can be reduced, potentially compromising the function of the heart and lungs. For example, the heart may have to work harder to pump the normal volume of blood or the affected individual may have shortness of breath.
Severe curvature of the lower half of the spine that connects the chest with the pelvis, known as the lumbar spine, may push the contents of the abdomen against the chest and interfere indirectly with heart and lung function. Curvature of the lumbar spine also may alter sitting balance and posture.
Severe curvature of either the thoracic (upper) or the lumbar (lower) spine, or both, eventually becomes visible to others. The resulting tilting and twisting of the back, shoulders and pelvis may produce an appearance that the individual finds unacceptable. If idiopathic scoliosis affects a girl around the time of puberty, when body image is developing hand-in-hand with self-esteem, the condition can pose significant psychological and emotional challenges.
Traditional medical management of scoliosis is determined by the severity of the curvature and skeletal maturity, which together help predict the likelihood of progression.
Conventional treatment options include: