Scoliosis

An in-depth report on the causes, diagnosis, treatment, and prevention of scoliosis.

Highlights

Scoliosis is an abnormal curving of the spine. Everyone's spine naturally curves a bit. But people with scoliosis have a spine that curves too much. The spine might look like the letter C or S.

Most of the time, the cause of scoliosis is unknown (idiopathic). Scoliosis can also be associated with congenital birth defects that cause a developing baby's spine to not form properly. Neuromuscular conditions are a third cause of scoliosis. These conditions include cerebral palsy, spinal bifida, and muscular dystrophy.

Scoliosis affects both boys and girls, but girls are more at risk for curvature progression (worsening).
Scoliosis is usually first noticed when children experience growth spurts, typically around the ages of 10 to 15 years.

The health care provider will ask the child to bend over to examine the alignment of the spine and tilt of hips and shoulder. Imaging tests such as x-rays, MRIs, or CT scans may be performed. The degree of curvature is measured using a technique called the Cobb angle.

Treatment for scoliosis depends on various factors, including the child's age, skeletal growth, accompanying medical conditions, degree of curvature, and risk for progression (curve worsening).

Treatment options include:

• Observation and monitoring of the child's condition is recommended for most cases of mild idiopathic scoliosis
• Bracing, which cannot correct the deformity but may prevent the progression of moderate curvture
• Spinal fusion surgery, which is usually reserved for cases of severe curvature

Introduction

Scoliosis is an abnormal sideways curving of the spine. A normal spine has gentle natural curves that round the shoulders and make the lower back curve inward.

In scoliosis, the spine curves from side-to-side to varying degrees. Some of the spinal bones may rotate slightly, making the hips or shoulders appear uneven. In severe scoliosis, the twisting in the spine can pull the rib cage into the rotation.

Scoliosis typically causes the spine to curve in one of the following ways:

• As a single curve to the left or right side (resembling the letter C)
• As 2 curves (resembling the letter S)

Scoliosis usually develops in the area between the upper back (the thoracic area) and lower back (lumbar area). It may also occur only in the upper or lower back.

The severity of scoliosis is determined by the extent of the spinal curve and the angle of the trunk rotation. It is usually measured in degrees. Curves of less than 20 degrees are considered mild and account for 80% of scoliosis cases. Curves that progress beyond 20 degrees need medical attention, usually involving periodic monitoring or bracing to make sure the condition is not becoming worse.

The Spine

• Cervical (C) vertebrae are the 7 spinal bones that support the neck.
• Thoracic (T) vertebrae are the 12 spinal bones that connect to the rib cage.
• Lumbar (L) vertebrae are the 5 lowest and largest bones of the spinal column. Most of the body's weight and stress fall on the lumbar vertebrae.

Each vertebra is designated by a letter and a number. The letter reflects the region (C=cervical, T=thoracic, and L=lumbar), and the number signifies its location within that region. For example, C4 is the fourth vertebra down in the cervical region, and T8 is the eighth thoracic vertebra.

Below the lumbar region is the sacrum, a shield-shaped bony structure that connects with the pelvis at the sacroiliac joints. At the end of the sacrum are 2 to 4 tiny, partially fused vertebrae known as the coccyx or tailbone.

Causes

Scoliosis is often categorized into 2 types:

• Nonstructural (functional) scoliosis is a normal spine that appears curved. Possible causes include having legs that are different lengths, or having a temporary injury or infection of the spine. The curve will go away when the underlying problem is resolved.
• Structural scoliosis is a fixed curve in the spine: Structural scoliosis may be due to idiopathic, congenital, or neuromuscular causes.

Idiopathic Scoliosis

In most cases, the cause of scoliosis is unknown (idiopathic). Because scoliosis often runs in families, researchers think that genetic factors may play a role. However, severity often varies widely among family members who have the condition, suggesting that other factors must be present.

Idiopathic scoliosis is classified based on age of presentation as:

• Infantile: Age 2 years and younger
• Juvenile: 3 to 9 years old
• Adolescent: 10 years and older

Idiopathic scoliosis is sometimes initially diagnosed in adults during evaluation for other back complaints or disorders. The curve may or may not be significant.

Congenital Scoliosis

Congenital scoliosis is caused by birth defects that affect spine formation and result in deformed or fused vertebrae. Congenital scoliosis has a high likelihood of progressing in severity. Children usually require early surgical intervention to prevent serious complications.

In addition to spinal problems, children with congenital scoliosis also have a higher risk for organ deformities that can affect heart, kidney, urinary, and nervous system function.

Neuromuscular Scoliosis

Neuromuscular scoliosis results from a medical condition such as:

• Cerebral palsy
• Spina bifida
• Muscular dystrophy
• Poliomyelitis (Polio)
• Spinal cord injuries or tumors
• Other conditions that affect the nerves and muscles surrounding the spine

Neuromuscular conditions can cause paralysis or weaken the muscles that support the spine. The curves caused by neuromuscular scoliosis are usually severe, and affect the entire length of the spine. This type of scoliosis is often accompanied by a condition called pelvic obliquity in which the pelvis is tilted to one side.

People with neuromuscular scoliosis are at risk for significant complications, including lung and heart problems.

Causes of Scoliosis in Adults

Adult scoliosis has two primary causes:

• Progression of childhood scoliosis.
• Adult degenerative scoliosis, a condition that typically develops after age 50. This condition is due to disk degeration, which is usually secondary to a primary condition such as osteoporosis (thinning bones) or arthritis. Adults with degenerative scoliosis may also develop kyphosis (hunched back).

Spina bifida is a congenital disorder (present at birth) in which the backbone and spinal canal do not close before birth. In severe cases, this can result in the spinal cord and its covering membranes protruding out of an affected infant's back. Spina bifida may be nearly inconsequential, or it may be repairable through surgery.

Risk Factors

Age

Scoliosis is usually first diagnosed in children aged 10 to 15 years, around the time they are experiencing growth spurts.

Sex

Scoliosis affects both boys and girls. However, girls are more likely than boys to develop progression (worsening) of the curvature.

Family History

Scoliosis often run in families. If both parents have scoliosis, their children face a significantly higher risk than if only parent has the condition.

Medical Conditions

Certain type of genetic disorders, such as Marfan syndrome, can increase the risk for scoliosis. Medical conditions and injuries that affect the spine can increase risk.

Risk for Curve Progression

People who have curve angle greater than 25 degrees are at highest risk for scoliosis progression.

Prognosis

In general, the severity of the scoliosis depends on the degree of the curvature and whether it threatens vital organs, specifically the lungs and heart. Scoliosis is classified as:

• Mild Scoliosis (10 to 25 degrees) . Mild scoliosis is not serious and requires no treatment other than monitoring.
• Moderate Scoliosis (26 to 40 degrees) . Scoliosis with a curve over 30 degrees has risks for progressing into adulthood. It also poses risk for other health problems.
• Severe Scoliosis (more than 40 degrees) . Scoliosis with a curve over 50 degrees nearly always progresses. It poses significant risks for health problems and reduced quality of life. If the curvature exceeds 70 degrees, the severe twisting of the spine that occurs in structural scoliosis can cause the ribs to press against the lungs, restricting breathing, and reducing oxygen levels. The distortions may also cause dangerous changes in the heart.

In general, the older the child the less likely it is that the curve will progress. Scoliosis in a child under 10, for example, is more likely to progress than scoliosis in an adolescent. Girls tend to have a higher risk for progression than boys.

The location of the curve is also a factor. Thoracic curves, those in the upper spine, are more likely to progress than thoracolumbar curves or lumbar curves (those of the middle to lower spine).

The higher the degree of curvature the more likely the chance of progression and the more likely the lungs and respiratory function will be affected.

People with severe deformities, particularly those caused by underlying neuromuscular disorders, may develop restrictive thoracic disease. This term refers to breathing problems and trouble getting enough oxygen due to a deformity-related smaller chest cavity. The restricted chest cavity is also less able to expand when breathing.

Symptoms

Scoliosis is often painless and may not be noticed until a child reaches adolescence. It may appear in casual circumstances, such as a parent noticing that a hemline is uneven. Most cases of scoliosis develop very gradually.

When symptoms become apparent they may include:

• One shoulder appearing higher than the other
• One hip appearing higher than the other
• Uneven waistline (one side of the waist may not curve in)
• A tilted head that does not line up over the hips
• A protruding shoulder blade
• Leaning more to one side than the other

Scoliosis may be suspected when one shoulder appears to be higher than the other, there is a curvature in the spine, or the pelvis appears to be tilted.

With more advanced scoliosis, fatigue may occur after prolonged sitting or standing. Scoliosis caused by muscle spasms or growths on the spine can sometimes cause pain. Severe scoliosis caused by neuromuscular conditions may have symptoms associated with trouble breathing.

Diagnosis

To diagnose scoliosis, the health care provider will take a detailed medical history and conduct a physical examination. Imaging tests may also be used to provide additional information.

Physical Examination

The child bends forward, dangling the arms, with the feet together and knees straight. The curve of structural scoliosis is more apparent when bending over. In a child with scoliosis, the provider may observe an imbalanced rib cage, with one side higher than the other, or other deformities.

The forward bend test is used most often in schools and medical offices to screen for scoliosis. During the test, the child bends forward with the feet together and knees straight while dangling the arms. Any imbalances in the rib cage or other deformities along the back could be a sign of scoliosis.

Other physical tests include:

• Walking on the toes, then the heels, then jumping up and down on one foot. Such activities indicate leg strength and balance.
• Checking leg length and looking for tight tendons in the back of the leg, which may cause an uneven leg length or other back problems.
• Checking for neurological impairment by testing reflexes, nerve sensation, and muscle function.

Identifying the Curvature

• The child bends over, arms dangling and palms pressed together, until a curve can be observed in the upper back (thoracic area).
• The scoliometer is placed on the back and measures the apex (highest point) of the upper back curve.
• The child continues bending until the curve can be seen in the lower back (lumbar area). The apex of this curve is also measured.
• Measurements are repeated twice, with the child returning to a standing position between repetitions.
• If results show a deformity, imaging tests will be used to determine the extent of the problem.

Imaging Tests

Imaging tests are used to provide further information on curvature. They include x-rays, and more advanced imaging tests such as magnetic resonance imaging (MRI) and computed tomography (CT). MRIs and CT scans use 3-dimensional imaging. However, MRIs do not expose people to radiation.

Measuring the Extent of the Curve

• On an x-ray of the spine, the examiner draws two lines.
• One line extends out and up from the edge of the top vertebrae of the curve.
• The second line extends out and down from the bottom vertebrae.
• The examiner draws a perpendicular line between the two lines.
• The angle formed between the two lines is the Cobb angle.

Classifying Scoliosis

Scoliosis is diagnosed when the Cobb angles measures 11 degrees or more. The severity of scoliosis and need for treatment is usually determined by two factors:

• The extent of the spinal curvature
• The angle of the trunk rotation (ATR)

Both factors are measured in degrees. These two factors are usually related. For example, a person with a spinal curve of 20 degrees will usually have an ATR of 5 degrees. However, most 20-degree curves do not get worse.

People do not usually need medical treatment until the curve reaches between 20 and 30 degrees, and the ATR is 7 degrees.

Treatment

The treatment choices for scoliosis are:

• Observation
• Braces
• Surgery

Decision to Treat or Wait

The general rule of thumb for treating scoliosis is to monitor and observe the condition if the curve is less than 20 degrees.

Curves greater than 25 degrees, or those that progress by 10 degrees while being monitored, may require brace treatment. Children who have severe scoliosis and are high risk for lung and heart problems may require immediate, aggressive treatment.

Choosing Braces or Surgery

In general, the following criteria are used to determine whether a child should receive a brace and conservative treatment or surgery:

• Braces tend to be used in children ages 3 to adolescence, with curvatures between 25 to 40 degrees, who will still be growing significantly. Braces can help prevent worsening (progression) but do not correct the existing deformity.
• Surgery is suggested for children with curvatures over 50 degrees or when braces have failed. In adults, scoliosis rarely progresses beyond 40 degrees, but surgery may be required if the condition causes pain, neurological problems, or other symptoms that interfere with quality of life.

The choice may not be so straightforward in certain cases, and it is important to discuss all options with your health care provider, including a doctor who specializes in orthopedics.

Braces

Braces are usually prescribed to prevent further progression of curves that are at least 25 degrees, and no more than 40 degrees. There should be documented progression of the curve, and the child should still be growing. A brace is generally used until the child's spine stops growing.

Braces are useful for idiopathic scoliosis. They are much less helpful for scoliosis caused by congenital or neuromuscular conditions. There is still uncertainty about which types of scoliosis curves are most likely to benefit from bracing.

Braces must be worn for at least 13 hours daily for positive results. Depending on your child's condition, the doctor may recommend wearing the brace for up to 23 hours a day. Some types of braces can be removed to accommodate participation in sports activities.

A brace is one type of treatment for scoliosis. The brace works by exerting pressure on the back and ribs to push the spine into a straighter position. The brace usually fits snugly around the torso and can come in many styles. Improvements in design have been made in recent years. In a child who is still growing, bracing is usually recommended to help slow the progression of the curve. Ideally, the brace is worn almost full-time until the bones have stopped growing.

Team Approach

A team approach, involving several health professionals, helps support the child through the bracing process:

• An orthopedic surgeon interprets the x-rays, assesses the potential scoliosis progression, and plans the treatment with the child and family.
• An orthotist measures and fits the child with the brace.
• A physical therapist may tailor an exercise program to the child.
• A nurse may also coordinate the treatment plans and provide guidance for physical and emotional support.

Types of Braces

There are 2 main types of braces:

Other less common types of braces include:

• The Wood-Cheneau-Rigo brace is another type of underarm brace.
• The nighttime Charleston brace is worn only while sleeping.
• The SpineCor brace uses adjustable bands and a cotton vest that allows flexibility. It is a soft elastic brace that differs from other most other braces, which are rigid plastic.
• The TriaC brace is another type of soft brace.

It is not clear if these alternative types of braces are as effective as standard ones.

Braces and Compliance

In order for a brace to be effective, it needs to be worn regularly and for the prescribed hours. Children should have a brace that will be most effective for them, and have the lowest impact on their quality of life.

Young people often refuse to wear braces, even the newer models. Emotional support from family and professionals is extremely important to help a child accept the process and stay compliant with the treatment.

Physical Therapy

Physical therapy may be used along with bracing. A specific physical therapy approach called the Schroft method is designed specifically for people with scoliosis. It focuses improving posture, abdominal strength, flexibility, and breathing.

Surgery

Surgery for scoliosis is usually recommended for:

• Growing children whose curve has gone beyond 40 degrees. (There is debate about whether all children with curves of 40 degrees should have surgery.)
• Children whose skeletons have fully matured, and who have a curve greater than 50 degrees

There are 4 main goals of scoliosis surgery:

• Straighten the spine as much as possible by correcting the deformity
• Balance the torso and pelvic areas
• Stop progression of the curve and maintain the correction long term
• Reduce pain symptoms and the risks for future heart and lung complications

It takes a 2-part process to accomplish these goals:

• Fusing (joining together) the vertebrae along the curve
• Supporting these fused bones with instrumentation (steel rods, hooks, and other devices) attached to the spine

Different instruments, procedures, and surgical approaches are used to treat scoliosis. All of the operations require meticulous skill and should be performed by a surgeon specializing in spine surgery.

The cause of scoliosis often determines the type of procedure. Other determinants include:

• The location of the curve (thoracic, thoracolumbar, or lumbar)
• Whether there are single, double, or triple curves, and the degree of rotation
• The size of the curve

You should always ask the surgeon and hospital about their experience with the specific procedures being considered.

Scoliosis surgery can take from 4 to 12 hours to perform. The child stays in the hospital for around 5 days, followed by 3 to 6 weeks of recovery time at home.

Before Surgery

Tell your child's surgeon what medicines your child is taking. This includes medicines, supplements, or herbs you bought without a prescription.

Before the operation your child will:

• Have a complete physical exam by the surgeon.
• Learn about the surgery and what to expect.
• Learn how to do special breathing exercises to help the lungs recover after surgery.
• Be taught special ways to do everyday things after surgery to protect the spine. This includes learning how to move properly, changing from one position to another, and sitting, standing, and walking. Your child will be told to use a "log-rolling" technique when getting out of bed. This means moving the entire body at once to avoid twisting the spine.

The surgeon or nurse will talk with you about having your child store some of his or her blood about a month before the surgery. This is so that your child's own blood can be used if a transfusion is needed during surgery.

During the 2 weeks before the surgery:

• If your child smokes, he or she needs to stop. People who have spine fusion and keep smoking do not heal as well.
• Two weeks before surgery, the surgeon may ask you to stop giving your child medicines that make it harder for the blood to clot. These include aspirin, ibuprofen (Advil, Motrin, generic), naproxen (Aleve, generic).
• Ask which medicines you should still give your child on the day of the surgery.
• Let the health care team know right away when your child has any cold, flu, fever, herpes breakout, or other illness before the surgery.

On the day of the surgery:

• You will likely be asked not to give your child anything to eat or drink 6 to 12 hours before the procedure.
• Give your child any medicines the doctor told you to give with a small sip of water.
• The health care provider will tell you when to arrive at the hospital. Be sure to arrive on time.

Surgical Approaches

The surgeon will make at least one surgical cut to get to your child's spine. This cut may be in your child's back, chest, or both places. The surgeon may also do the procedure using a special video camera.

The basic surgical approaches are:

• Posterior approach . The surgeon reaches the spine by making a cut in the back. This is usually the standard approach.
• Anterior approach . The surgeon makes a cut through the chest wall (called a thoracotomy), deflates a lung, and removes a rib. The rib may be used during the operation to support the spine, or it may be repositioned and later used for bone grafting during spinal fusion.
• Combined anterior-posterior approach . The combination approach uses an anterior approach first, which allows better correction of the problems. The fusion part of the operation is done with the posterior approach. This method may correct large rigid curves and specific severe curves in the thoracic spine.
• Video-Assisted Thoracoscopic Surgery (VATS) . This method uses a video-assisted anterior approach and specialized spinal instrumentation. The procedure is complicated and surgeons must be specially trained to perform it. It is generally reserved for specific types of curvatures. Children must wear a brace for 3 months following surgery.

Spinal Fusion Procedure

Most scoliosis operations involve fusing the vertebrae. The instruments and devices used to support the fusion vary.

Before surgery, your child will receive general anesthesia. This will make your child unconscious and unable to feel pain during the operation.

In the spinal fusion procedure, the surgeon will:

• Raise flaps to expose the backs of the vertebrae that lie along the curve.
• Remove the bony outgrowths along the vertebrae that allow the spine to twist and bend.
• Lay matchstick-sized bone grafts vertically across the exposed surface of each vertebra so that they touch the adjoining vertebrae.
• Fold the flaps back to their original position, covering the bone grafts.

These grafts will regenerate, grow into the bone, and fuse the vertebrae together. Bone grafts will help keep the spine in the correct position.

Surgery for scoliosis involves correcting the curve (although not all the way) and fusing the bones in the curve together.

Bone grafts can be acquired from:

• Autograft , a bone graft from the child's own hip, rib, spine, or other bone area in the body. Autografts work well, but because they require an additional incision and surgery, they cause more pain during the post-surgical recovery process.
• Allograft , a bone taken from a cadaver. Allografts are usually gotten from a bone bank. These type of grafts can sometimes increase the risk for infection.
• Synthetic grafts which are made from biologically-manufactured human bone protein, may be another option.

There are various types of instrumentation procedures. They include the Harrington procedure, the Coutrel-Doubousset procedure, and the Texas-Scottish-Rite Hospital instrumentation procedure.

The metal instruments are usually left in the body after the bone fuses together. In certain circumstances, a rod may need to be removed.

Complications

In addition to allergic reactions to anesthesia, infection, pain, and other standard surgical risks, specific complications associated with scoliosis surgery may include:

• Blood loss that requires a transfusion
• Nerve injury causing muscle weakness or paralysis (very rare).
• Gallstones or pancreatitis (inflammation of the pancreas).
• Intestinal obstruction (blockage).
• Lung problems up to 1 week after surgery. Breathing may not return to normal until 1 to 2 months after surgery.

Problems that may develop in the future include:

• Fusion does not heal. This can lead to a painful condition in which a false joint develops at the site. This condition is called pseudarthrosis.
• The parts of the spine that are fused can no longer move. This puts stress on other parts of the back. The extra stress can cause back pain and make the disks break down (disk degeneration).
• A metal hook placed in the spine may move a little. Or a metal rod may rub on a sensitive spot. Both can cause some pain.
• New spine problems may develop, especially in children who have surgery before their spine has stopped growing.
• Some children may later need a corrective procedure called revision or salvage surgery. This is usually performed to correct a failure of the previous procedure or address issues with disk degeneration or curvature progression at fusion site.

Recovery and Outcomes

Your child's spine should look much straighter after surgery. There will still be some curve. It takes at least 3 months for the spinal bones to fuse together well. It will take 1 to 2 years for them to fuse completely. Children can resume many physical activities in the weeks and months after surgery, but will need to wait until the spine is fully healed before participating in contact sports.

Fusion stops growth in the spine. This is not usually a concern because most growth occurs in the long bones of the body, such as the leg bones. Children who have this surgery will probably gain height from both growth in the legs and from having a straighter spine.

Your child will be given pain medication in the hospital and will be discharged with a prescription for pain meds that can be taken for a few weeks. When prescription pain medication is stopped, the child can be given acetaminophen (Tylenol, generic) to cope with pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, generic), are not recommended because they may increase the risks for bleeding.

The health care team will give instructions to the parents about how to lift and move the child. For some types of procedures, the child may need to temporarily wear a brace to help prevent rotating movements that could delay recovery. During the initial weeks of recovery, the child should avoid movements that involve bending, lifting, or twisting.

Your child may need to see a physical therapist to receive an individualized exercise program that includes exercises for stretching and strengthening. An occupational therapist can provide exercises for activities of daily life, such as techniques for tying shoes, dressing, bathing, and cutting food.

Children can usually return to school about 1 month after spinal fusion surgery.

Other Types of Surgery

Resources

• www.scoliosis.org -- National Scoliosis Foundation
• www.srs.org -- Scoliosis Research Society
• www.aaos.org -- American Academy of Orthopaedic Surgeons
• www.niams.nih.gov -- National Institute of Arthritis and Musculoskeletal and Skin Diseases