Spinal Fusion for the Treatment of Idiopathic Scoliosis in Children

Last updated: December 30, 2009

Overview

Idiopathic scoliosis is a curvature of the spine that occurs in children and young teenagers.

This condition affects about 2 to 3 percent of children under the age of 16. Most of the time the curve in the back will remain small and will not progress however with growth and over time it may worsen. This condition causes a visible deformity or a bump that appears on the child’s ribs or in the muscle adjacent to the spine.

In most cases the curve will stop progressing or changing once the child stops growing. However curves that are very large may continue to worsen in adulthood even though the individual is no longer growing.

Spine surgery is sometimes performed to correct the curve and fuse of the affected part of the spine.  This surgery causes the bones of the spine to grow together to become a solid bone that can no longer twist.  Metal rods are placed into the spine to pull it into a corrected position and to hold it there in a stable manner. This allows the bones to heal together much as a broken bone in the arm or leg would heal.

Patients are able to get out of bed within a few days of surgery while the average patient length of hospital stay is about five days.  Full recovery takes approximately three to six months.

Characteristics of idiopathic scoliosis

Scoliosis usually appears as a bump on the chest or muscle adjacent to the spine. This bump is caused by the rotation of the spine as the curve increases. Internal organs are in general not damaged by worsening scoliosis. However sometimes curves located in the chest can affect the lungs and cause difficulty in breathing.  This happens when a curve in the chest or upper spine area becomes extremely large. The effects of this curvature are generally seen in the mid to late adult years. There has been some concern that large spinal deformities in the lower portion of the spine (“lumbar”) may lead to degenerative changes of the lower back over a period of 40 to 50 years.

Types

Idiopathic scoliosis means that the scoliosis does not have a definite cause. Children with idiopathic scoliosis are otherwise normal. The only subtypes of this condition are related to age.

This condition is classified as either “early onset” or “late onset” scoliosis. Early onset is recognized in children under 8 years old while late onset starts after the age of 8. Children who develop large curves at a young age may experience adverse lung development and growth that can lead to an early death due to breathing difficulties.

Similar conditions

Other types of scoliosis are congenital and neuromuscular scoliosis.

In congenital scoliosis patients have malformed bones that grow crookedly over time. Children are born with this condition and the cause is unknown. The management of these patients is very different from those with idiopathic scoliosis. Surgery is generally needed to correct or control these deformities.

Children with neuromuscular scoliosis will have associated underlying abnormalities such as cerebral palsy muscular dystrophy or many other neurologic or genetic syndromes that may affect the scoliosis.  It is important when evaluating children to exclude other associated conditions by a careful medical and developmental history and physical examination.

Incidence and risk factors

Idiopathic scoliosis affects approximately 2 to 3 percent of all children under the age of 16. It is estimated that about 1 in 1 000 people will experience significant progression of their scoliosis. The frequency of small curves in girls and boys is equal.  For curves that are progressive however statistically girls out number boys 7 to 1.

Diagnosis

Idiopathic scoliosis can be diagnosed through a careful physical examination by a physician. This examination involves the patient bending forward while he or she is standing in front of the physician and leaning either toward or away from the physician. A key sign of this condition is asymmetry of the ribs or surrounding muscles due to rotation of the spine. This presents as a bump along the spine and can be easily recognized when the child bends forward.  X-rays of the spine can confirm whether or not scoliosis is present.

Medications

No. Medication has not been shown to affect the progression of scoliosis.

Exercises

To date no exercise regimen or program has been shown to affect the likelihood of curve progression for scoliosis. Muscle strengthening or generalized conditioning may help mechanical back pain problems.

However some patients particularly younger patients with curves that are not severe can be treated with a brace. There is some controversy about this but there are some studies that have shown this to be effective when used in the appropriate patients. Non-operative intervention such as massage physical therapy chiropractic manipulations exercise programs and electric stimulation do not adversely affect the spine but have not been shown to stop or prevent the progression of scoliosis.

Possible benefits of idiopathic scoliosis

Spinal fusion has been shown to be very effective in correcting the deformity and preventing further progression of scoliosis. Spinal fusion is generally recommended if other non-operative methods of controlling scoliosis have failed.

Types of surgery recommended

There are several different types of surgical options for idiopathic scoliosis.

The most common is to perform a spinal fusion where a surgical incision is made and the spine is exposed either from the back which is called a posterior approach or from the side which is called an anterior approach. Rods are fixated to the spine from the direction of the approach. Over the last 10 to 15 years the use of anterior spinal procedures has increased. These procedures involve approaching the patient from the side and inserting the metal rods to support the spine. The rods are attached directly to the vertebral bodies.

Most recently instrumentation can be inserted using a minimally invasive  procedure called thoracoscopy.  Telescopic instruments are inserted into the chest with the lung deflated and metal rods can be attached to the vertebra without needing to make large incisions.  The technique is useful for moderately large curves in the chest but is technically demanding and is best done by medical centers with extensive experience in thoracoscopic work.

Who should consider idiopathic scoliosis?

Q: Patients who have a curve in the chest area where the spine is tilted more than 50 degrees or are curved in the lower portion of the back where the spine is tilted more than 40 to 45 degrees should consult a spinal deformity specialist for information regarding surgical procedures such as spinal fusion.

What happens without surgery?

In the best case the scoliosis remains stable throughout the patient’s adult life and creates no particular problems. This is especially true for curves that are “borderline”. If a child is finished growing and the curve in the chest is 50 to 60 degrees or if the curved lower portion of the back is 40 to 45 degrees and the child is not experiencing symptoms or is not bothered by his or her back it is reasonable not to perform surgery on these patients. 

The worse case scenario for scoliosis is that the deformity will progress over time.  If that occurs then delaying surgery is not recommended as the deformity can become quite severe and increasingly difficult to manage.  Also the risks of surgery will increase with an extremely large deformity. 

Surgical options

As outlined above conventional options include spinal fusion through either a posterior or anterior approach. In some cases a combination of an anterior and posterior approach will be necessary to effectively stabilize the back.

For very young children with scoliosis that is progressive and for whom bracing has not been successful stabilization of the back may be done by inserting metal rods to support the spine without performing a spinal fusion.  This type of procedure is called insertion of a “growing rod.”  The rods need to be elongated about every six months with surgery.

A newer method involving stapling of the spine to try to modulate the growth is currently under review but it is not yet approved for general use. 

Effectiveness

The success rate of stable fusion and correction of spinal deformity is very high in experienced hands. The average curve correction is approximately 70 percent and the likelihood of complications has been about 2 to 3 percent overall. The fusion of the bones (enabling the bones to grow together) is permanent.

There are concerns about long-term degenerative arthritis that may appear 30 to 50 years later in segments of the spine that were not fused. Currently there is not adequate follow-up information on the procedure to know the frequency of this problem.

Urgency

The urgency of spinal fusion is based on how rapidly the curve is changing. For a child who is in the early stages of their pubertal growth spurt the spine can increase deformity at a rate of up to 2 to 3 degrees per month so while scoliosis surgery is plainly not an emergency neglecting rapidly progressive curves for long periods of time is not a good idea

As an adult or someone in the later stages of growth the rate of change will only be 1 to 2 degrees per year therefore the urgency is less.    

In general waiting six months to a year is an acceptable time to wait to have fusion surgery. 

Risks

The most common risks of spinal fusion surgery for scoliosis are:

1) Infection: risk of infection is approximately 1 to 3 percent for idiopathic scoliosis. There is an increasingly recognized possibility that infection can occur for up to two to three years after the initial procedure.

2) Failure of the bone to fuse: the failure of the bones to grow together and heal with scar tissue rather than bone occurs in 1 to 2 percent of cases in children. In these cases repeat surgery will sometimes have to be performed to get the bone to effectively grow together. This concern may not be apparent for several years after the initial procedure. 

3) Injury to the spinal cord resulting in partial or permanent paralysis of the lower extremities: the risk of this injury has been reported from 0.2 to 5 percent of cases depending upon where the procedure was performed on the spine and the seriousness of the deformity that has been treated. 

Managing risk

Managing risks that occur involves the following:

1) Infections following spinal fusion surgery are not generally life threatening to the patient. They may require additional surgery to clean out the infection long-term use of antibiotics until the bones are solidly healed and in some cases may require removal of the metal rods and implants to allow for final treatment of the infection.

2) Problems with bone healing are best managed by having the patient go back to the OR for a follow up procedure to re-stimulate the healing process by surgically grafting bone to the area involved and replacing some of the instrumentation used to stabilize the spine

3) Injuries to the spinal cord that lead to paralysis with loss of lower limb function may require removal of implants to relax the correction of the scoliosis. It is thought that a blood flow problem to the spinal cord may be created.  By relaxing the spine tension will be alleviated and this should help patients regain function. Eventually the spine implants will have to be replaced but in a less “corrected” position.

Preparation

Children are advised to be in good general health and well nourished.   Problems of infection and bone healing increase in situations where the patient doesn’t have adequate calorie or protein intake. In most healthy young people this will not be an issue.

Timing

As long as the curve is not changing dramatically surgery can be postponed indefinitely. If a curve is stable and changing at a very slow rate the observation period can be quite long. In general surgery to treat a curve that is increased by 10 to 15 degrees is not more complicated or difficult.  However if a curve increases by 30 to 40 degrees the magnitude of difficulty of surgery is greater and safety is less certain.

Costs

Most commercial and government-sponsored insurance plans will cover this procedure. Many children in the state of Washington and nationally are covered by Medicaid which will also cover the cost of the surgery.

Surgical team

Spinal fusion is a complicated and technically demanding procedure. This procedure should be performed by a medical team whose members perform a high volume of these surgeries and at institutions where they are experienced in spinal cord monitoring and offer good anesthesia support. For younger children undergoing this procedure the team should include a pediatric anesthesiologist.

If an anterior spinal fusion is performed the surgeon should have experience with chest and abdominal procedures. If thoracoscopic procedures are to be performed there should be a team in place that has received formal training in these techniques and is experienced with thoracoscopy procedures.

Finding an experienced surgeon

A good resource for spinal surgeons is the Scoliosis Research Society (www.srs.org). This organization includes surgeons who perform high volumes of spine surgery and are skilled in spinal reconstruction for pediatric spine conditions.

Another source is the Pediatric Orthopedics Society of North America web site.  The site includes a listing of skilled orthopedic surgeons who have experience in pediatric conditions. 

Facilities

The majority of spinal fusions for childhood scoliosis are performed in major pediatric children’s hospitals in North America. Adult facilities may also have expertise provided they have a pediatric unit and a designated and skilled spine team.

Technical details

For posterior procedures the spine is exposed after the patient is positioned face down on a special frame. Then the patient’s X-ray is used to guide the surgeon in placing hooks or screws into the vertebrae where rods are later attached. The joints between the bones are removed and then the spine is straightened by attaching rods to the hooks or screws. The spine is then repositioned and the screws and hooks are tightened securely to the rod.

Usually bone grafts serve as scaffolding for new bone cells to grow into. The bone graft can be taken from the patient or can be taken from the bone bank. In children either bone supply works equally well for healing. It is advisable to discuss the options thoroughly with the surgeon and to evaluate the pros and cons of either bone graft source.

The spinal cord is monitored throughout surgery to track impulses up and down the spinal cord.  This is a precaution taken to add an extra margin of safety and to decrease the possibility of cord injury.  Following surgery a brace may be used for added support depending on the patient’s condition.  In the majority of cases (in 2005) braces were not used. 

For anterior procedures the patient is placed on his or her side.  An incision is made to the spine either through the flank for the abdominal area or through the chest for the thoracic area. Screws are placed into the bone and the discs between the vertebrae are removed. Bone is then placed into these areas to help stimulate bone healing in between vertebrae.  A rod is attached to the screws and the spine is straightened and locked securely into position.  Braces are often not used after surgery.

After either anterior or posterior surgery a tube is typically left in to drain off any bleeding that occurs after the surgery. 

Anesthetic

Monitoring of spinal cord function is done during scoliosis surgery. The standard monitoring should include monitoring of the pathways that transmit sensation and of the pathways that transmit motor movement. Most patients are administered general intravenous (IV) anesthetic. A medication called Propofol is often used along with pain medication and Nitric Oxide which is a gas to help sedate the patient and help him or her drift off to sleep. The use of paralytic agents is often avoided due to the potential of interfering with the spinal cord monitoring.

Length of idiopathic scoliosis

The length of surgery depends on how much of the spine needs to be fused and the approach that is used. Most anterior or posterior surgical procedures take three to five hours. The actual time in the operating room is longer than just the surgery because there is a need to apply monitors and position the patient appropriately for surgery. If a thoracoscopic procedure is performed the length of time is a bit longer then it is for a more conventional open approach.  If a combined anterior and posterior spinal fusion is performed the surgery may take up to 8 to 10 hours.

Pain and pain management

Scoliosis and spine surgery can be quite painful. In major medical centers where spinal fusions are performed on a regular basis there is often a pain service with specially trained staff to help manage the patient’s pain after surgery. Intravenous use of medications such as morphine are used. This is often given with a patient controlled analgesic (PCA) which is a pump with a push button allowing for more rapid delivery of medication when necessary. Typically intravenous pain medication is used for three to four days after the procedure. The patient usually transitions to oral medication by day four or five. Patients are then discharged from the hospital on oral pain medication.  More recently epidural catheters have been left in the space adjacent to the spinal cord and pain medications are delivered directly to the spine for a few days before transitioning to oral pain medications.

Pain medication will generally be needed for two to three weeks after discharge from the hospital. The pain is usually managed well with oral medications by the time the patient leaves the hospital. At this time they are also able to move about without much limitation. 

Effectiveness of medications

Nausea and vomiting are common when taking pain medication. Additionally constipation can be a significant problem and may require stool softeners or other medication to help with bowel movements. Sedation and sleepiness after pain medication is also common.

Hospital stay

The typical course of recovery after spinal fusion is for the patient to sit on the edge of the bed the first day after surgery. By the second day after surgery the patient is up and walking in the room and later in the hallway. Pain medications are given by IV for three to four days after surgery. A liquid diet is started shortly after surgery and is advanced rapidly to a regular food program. 

X-rays are taken with the patient in an upright position three to four days after surgery to make sure the spinal instrumentation is in the same place it was left at the end of surgery. On average the length of stay is about four to five days in the hospital.

Recovery and rehabilitation in the hospital

A physical therapist will initially assist the patient in getting out of bed. Following that the goal is to have the patient move independently and to be able to get out of bed with only minimal assistance by the time they are discharged.

Most patients are extremely tired and fatigued for about three to four weeks after the operation. This is because the body requires a large amount of energy to heal from surgery like this and because blood counts are low due to blood loss during surgery. By four or five weeks after the surgery most patients are feeling pretty well and by six weeks frequently parents must slow their children down to avoid a too rapid return to full activity. 

Hospital discharge

Generally patients will be restricted from sport activities and heavy lifting for at least six weeks. After six weeks patients are allowed to do a little bit of light swimming. The weight limitation for lifting is about 10 to 15 pounds. School-age patients will typically miss about four weeks of school. Parents are advised to secure an extra set of books at school so patients do not have to carry a heavy backpack to and from classes and to arrange for children to be released from class a few minutes early to avoid the rush in the hallways. 

After three months patients may return to light sports. This includes running on level ground swimming and riding a bicycle.

After six months they can return to full activity.

Convalescent assistance

Patients can go home following spinal fusion for idiopathic scoliosis and they do not require a convalescent facility. They will need some help from their family members to move up and down stairs and to walk until they can do so without assistance.

All rehabilitation can be completed at home and does not require special expertise. The goal in the first four to six weeks after surgery is simply to increase the distance of walking each day. 

Summary of idiopathic scoliosis for idiopathic scoliosis

  1. The overall complication rate for spinal fusion is low. The most worrisome complications are infection problems with bone healing and paralytic injury to the spinal cord. These complications are rare but if they occur they may require additional surgery.
  2. The recovery period from scoliosis surgery is fairly predictable. The average length of stay is about four to five days in the hospital and length of time to recover to more functional daily activities is about four weeks. Return to full activities should occur about 3 to 6 months out from surgery.
  3. Spinal fusion surgery for idiopathic scoliosis addresses problems of deformity and progression of deformity well. However it does not make the back normal and so the patient may experience degenerative problems in 30 to 50 years which may require additional treatment.
  4. Spinal fusion surgery is technically demanding and should be performed by highly skilled medical teams whose members perform high volumes of scoliosis-related surgical cases.
  5. The medical facilities performing this type of work should have in place a very good spinal cord monitoring team in addition to excellent anesthesia support. The team effort is key to ensuring successful outcomes for patients.
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