Adolescent Idiopathic Scoliosis

What is Scoliosis?

   Scoliosis is defined as a curvature in the spine from side to side (spinal curves from front to back are called kyphosis). Since many people have very small curves in the spine that are of no real consequence, a curve must measure more than 10 degrees to be called scoliosis. There are many different causes for scoliosis. When the vertebrae themselves are abnormally shaped because of failure of the vertebra to form correctly or separate correctly, we call it Congenital Scoliosis. When a spinal curvature occurs with another known syndrome or condition that affects the nervous system (such as cerebral Palsy or spina bifida), it is called Neuromuscular Scoliosis. When there is no clear cause of the curvature in a healthy person, it is called Idiopathic Scoliosis. This type of scoliosis is the result of an abnormal rotation of the vertebra. Scoliosis can involve the upper back (thoracic), mid-back (thoracolumbar), or in the lower back (lumbar). The neck is seldom involved in scoliosis, and is never part of idiopathic scoliosis.

   Adolescent idiopathic scoliosis is the most common type of spinal curvature. It occurs between the onset of puberty and age 18 in otherwise healthy boys and girls. The prevalence of scoliosis in the USA is 2 – 4% for curves as little as 10°. Girls are far more likely to have larger curves and curve progression than boys. We don't know why. For boys, curves are more likely to progress through the late teen years as long as skeletal growth continues.

Causes

   Unlike many types of scoliosis, the cause of adolescent idiopathic scoliosis is unknown. It does seem to run in families but is not strictly inherited. The likelihood of scoliosis is greater where there is a family history. Cases can also occur where there is no family history of scoliosis. The more that is learned about causation, the more complicated this deformity appears to be. Research is ongoing to try and connect the disorder to a specific gene or group of genes.

Signs and Symptoms

  Adolescent idiopathic scoliosis is a painless spinal deformity. The curve in the spine does not cause pain. If pain is present, it should be investigated further and not attributed to the curve.

   The most common physical finding in teens with scoliosis is the prominence of the ribs on one side. This so-called "rib hump" is best observed by parents or health care providers when viewing the teen bending forward. The ribs on one side of the back will often seem higher than the other side. Other findings include one scapula or shoulder blade that may seem more prominent than the other is. Careful observation of the standing teen may also reveal that one shoulder is higher than the other. One hip may seem higher and give the appearance that one leg is longer than the other is (it usually is not). Clothes fit differently than they used to. There are also patients who have a large curve and hide it very well clinically, without much noticeable deformity.

What Happens to Teens Who Have Scoliosis?

  For teens with scoliosis, the period of time carrying the greatest risk that the curve will get bigger (curve progression) is during the adolescent growth spurt. For girls, this may be from age 11-14 and usually lasts for 18 months after the first menstrual period. For boys, it is usually between ages 13-17. During this period of rapid growth, the curve can increase up to 1 or 2 degrees per month. It is not uncommon for parents wonder where the curve came from so quickly. Some parents feel guilty for not noticing the curve sooner. The nature of adolescent idiopathic scoliosis is one of possible rapid progression, and parents should not feel guilty. The likelihood of curve progression depends on the size of the curve in relation to the amount of growth the teen has remaining. For young teens who are still growing and have curves greater than 20 degrees, there is a 68% chance the curve will get larger over the next few years. If a teen’s growth is nearly complete and the curve is around 20 degrees, there is less chance the curve will ever increase. Most small and medium sized curves stop getting bigger once the body is finished growing. The spinal curvature will continue to be the same size throughout life that it was when the patient was a teen. If the curve is more than 40-50 degrees during the teen years, it will likely continue to get larger during adulthood, though at a much slower rate.

Conservative Treatment Options

  For simplicity and patient education, we break down scoliosis into three levels of severity.

  SMALL CURVES: 10-25 degrees. These patients are treated with observation. For teens still growing, follow-up x-rays are needed every 4 months until growth stops.

  MEDIUM CURVES: 26-40 degrees. If the patient is still growing, a brace should be considered. We use a custom molded TLSO (thoraco-lumbo-sacral orthosis) for most patients and our success rates have been similar to the national experience. The brace is about 70% successful at preventing curve progression. Nearly one third of patients that wear the brace experience curve progression anyway. The brace does not make the curve improve or go away. Successful bracing means that the patient avoids surgery because the curve does not increase. Successful bracing keeps the curve at the same degree it was when bracing was started.

   Certain types of braces (TLSO, Boston, Milwaukee, and Charleston have been studied by members of the Scoliosis Research Society and are successful in treating scoliosis. Some other types of braces have been widely advertised by their entrepreneur developers but their use is not supported by adequate data. If you have any questions about whether your brace is adequate, contact the Scoliosis Research Society or a SRS member in your area.

  Treatments which have been shown to have no affect on curve progression include physical therapy, an exercise program, chiropractic manipulation, medications, and electrical muscle stimulation. A brace is the only form of conservative care shown to affect the progression of scoliosis when compared to no treatment at all.

  LARGE CURVES: 45 degrees and higher. These patients have a large enough deformity to warrant surgery in many cases. Remember that bracing does not improve a curve. It only prevents the curve from getting larger, if it works. Wearing a brace is a less attractive option for severe curves since the curve will still be large at the conclusion of treatment. For this reason, bracing is usually not an option for these patients. Without surgery, progression of these large curves during adulthood still remains a risk.

Surgery for Adolescent Idiopathic Scoliosis

  The decision to have surgery to correct scoliosis is a highly personal decision. This type of decision should always be made on an individual basis with consultation from the patient, parents, and their Spine Surgeon. Many patients and their families find additional information from national and local scoliosis support groups. We encourage our patients get in touch with the Arizona Chapter of the Scoliosis Association (480-839-9822).

Indications For Surgery (Who Needs It?)

Patients with any of the following could be candidates for surgery:

• Curves greater than 40 - 45 degrees in a teen who is still growing
• Large curves which cause spinal imbalance
• Curves associated with neurological signs and symptoms (Not adolescent idiopathic)
• Curves larger than 50 degrees in patients who have stopped growing

Surgical Approaches

   There are three approaches to scoliosis surgery currently used, namely anterior only (from the front), posterior only (from the back), or combined anterior and posterior. There are various techniques using these approaches.

  Anterior - This is done by making an incision in the side of the chest or flank, removing the discs, and filling them with bone graft often taken from a rib. The bone goes on to heal and the spine becomes fused. Screws are inserted into the vertebrae and a rod connects the screws. The spinal curvature is corrected and held in place with the rod and screws. Screws, rods, and hooks are usually made from a titanium alloy or from surgical grade stainless steel.

  Posterior - This is the traditional technique for surgically treating scoliosis, approaching the spine from the back. The muscles are spread aside (not cut) and the spine is exposed. Bone screws and sometimes hooks or cables are used to attach to the spine and are connected together by rods. The hooks, screws, and rods are manipulated to correct the deformity, and bone graft is laid on top to fuse the spine in its new straightened position.

  Combined Anterior and Posterior (Front-Back) - This is reserved for very young patients or those with the largest and stiffest spinal deformities. Both front and back surgeries are usually done the same day under the same general anesthetic. The anterior part is usually done first and can often be done through the scope, saving patients from a large flank incision (see section on thoracoscopic surgery). The posterior surgery follows.

Results

  The object of surgery is to safely straighten the curve and stop its progression. Safety is always first. In most cases, the severity of the curve can be improved at least 50% (average of 67%) with surgery. We do not try to make the spine perfectly straight since it is usually not safe to do so.

  Our success rate at achieving our surgical goals without any complications is about 92%. Patients and parents are almost always happy with the functional and cosmetic results.

Complications

  The most common complication is the failure of the spine to fuse solidly, despite good bone graft and instrumentation. These so-called "nonunions" occur in 5% of patients. If there is no loss of correction and if there is no pain associated with the nonunion, it can be observed without further surgery. If pain is present, revision surgery may be required to fuse the unfused segment.

  There is a 2% risk of infection with this type of surgery. It occurs despite antibiotics being given before, during, and after surgery and is usually attributed to bad luck. When it is diagnosed, usually in the first several weeks following surgery, a revision surgery is needed to thoroughly clean out the spine wound in order to prevent a chronic infection from setting in. Occasionally more than one "wash out" surgery may be required to get rid of the infection.

  The risk of instrumentation failure is about 1%. When this happens, revision surgery may or may not be required, depending on several factors.

  Other complications can occur but are very rare, occurring in less than 1 per 100. According to the Scoliosis Research Society data, the risk of paralysis with scoliosis surgery is about 1 per 2000 cases. Thankfully, we have never had a case.

  We have our patients donate blood before surgery whenever possible. It they need blood, we give them their own blood back. The risk of contracting hepatitis from a blood transfusion from the blood bank is around 1 per 10,000. The risk of getting AIDS from infected blood is about 1 per 100,000. Neither of these risks applies if the patient receives their own blood back.

  The risk of death from surgery is about 1 per 1,000,000. Thankfully, we have never had a case.

Recovery

  Even though we have come light years in our technology and approach to scoliosis surgery since the 1970's, it is still major surgery. Hospitalization is usually about 4-6 days. Teens are up walking right away and are ready to go back to school in 3 weeks (no lifting more than 5 pounds). No exercise more than walking is allowed for the first 6 months. After that, jogging and gentle swimming is started. After 9-12 months from surgery, patients are allowed to do most everything except collision sports (football, rugby, rodeo, etc.).

Long-Term Outlook After Surgery

  Once the spinal curvature is corrected and successfully fused, a normal or near normal life can be resumed. Most people do not have significant back pain, even long after surgery. Patients who were fused low in the lumbar spine (L4 or lower) while in their teens are more likely to have some back pain later in life.

  In some patients over time, arthritis develops in the next level below the fusion. When this occurs, back pain slowly increases as the arthritis increases. Bone spurs may form and pinch the spinal nerves, causing leg pain. This is called spinal stenosis. To alleviate the pain, surgery is required to clean out the bone spurs and extend the fusion lower in the lumbar spine.

  About 5% of patients will at some point in their lives need to have their hooks and rods removed for some reason. Occasionally, a fluid collection or bursa forms over the implants and they become painful to touch and hurt with changes in the weather. Surgery to remove hardware is no where near as major as the initial surgery.

What If My Curve Is Large But I Decide Not to Have Surgery?

  Spine surgeons who take care of both adult and pediatric patients with scoliosis as we do often have 30 and 40 year old women come in with moderately severe scoliosis. These women invariably tell stories of not being allowed to have surgery in their teens. Later, as mature adults, they want to have their curves corrected and regret that they did not do it as teens when it would have been more convenient with a quicker recovery and better correction while the spine is more flexible. This is a very common scenario.

  Thoracic curves that are allowed to become large can cause general health problems. As the curved spine takes up more space in the chest, patients become short of breath with exercise and minor activity. Very large curves can even lead to congestive heart failure. Measurable lung function decline begins when curves are in the 70-80 degree range.

  Large curves in the lumbar region often lead to premature spinal arthritis. This causes back pain, spinal imbalance, and spinal nerve compression during adulthood. The trunk shortens as the curve increases, and the ribs begin to rub on the rim of the pelvis. The lumbar spine does not have any outside support such as the rib attachments in the thoracic spine. Once the curve reaches a certain point, it often becomes relentlessly progressive.

  There are also some obvious cosmetic consequences to having a large untreated scoliosis. One study from Sweden even found that women with severe scoliosis were much less likely to get married. While no one would ever suggest that surgery should be done for purely cosmetic reasons, the body contour improvements that accompany surgery can be very gratifying.

© 2005 Sonoran Spine Center, P.C.