Adolescent idiopathic scoliosis (AIS) is curvature of the spine that occurs as a phenomenon of growth. Idiopathic simply means there is no cause for it. Some instances of scoliosis are secondary to other medical conditions (i.e. Neurofibromatosis, Cerebral Palsy, etc). Dr Balakumar is a Melbourne based specialist in Adolescent Idiopathic Scoliosis.

The vertebrae is the series of bones in the spine. The vertebra are connected to each other by ligaments, and there are soft discs in between the vertebra of the spine. The vertebra are connected to each other by small joints called facet joints from top to bottom.

These vertebra make up different sections of the spine from top to bottom. These sections include the cervical (vertebra in the neck), thoracic (vertebra in the chest), lumbar (vertebra of the low back) and sacral (located just above the tail bone). Each vertebra is numbered, starting at the top in each section as number one.

AIS is a diagnosis of exclusion, meaning other diseases or causes have to be ruled out first. Dr Balakumar will mainly do this with physical examination and investigations if he is suspicious.  Even though scoliosis is a three dimensional deformity, the way we measure this is using a two dimensional film. The X-ray of the spine measures the two most tilted vertebrae. It is defined as a persistent lateral curvature of the spine of more than 10 degrees in the upright or standing position. Although the lateral curvature is the main component, it can also be associated with rotation of the spine, and different plane curvatures.  A sideways view is also taken to check for, either a flat back, or excessive forward bend (kyphosis).

Scoliosis is divided into three categories:

1. Congenital
2. Neuromuscular
3. Idiopathic

Congenital scoliosis indicates the patient was born with the curvature of the spine and is caused by a failure of the vertebrae to individually form or separate from each other.

Neuromuscular scoliosis is caused by a wide variety of disorders which include cerebral palsy, Duchenne muscular dystrophy and myelomeningocele (also known as spina bifida). Each of these categories is very different and requires different treatment interventions than adolescent idiopathic scoliosis.

Idiopathic means the identifying cause of the disease/disorder is unknown. Research into the cause has targeted multiple areas and exemplifies the complex nature of this disorder. The current consensus is that it is a multifactorial process that includes altered melatonin production, connective tissue disorder, skeletal muscle abnormalities, contractile protein dysfunction or a nerve function problem.

How do we classify scoliosis?

• Mild - 10-25 Cobb Angle
• Moderate - 25-45 Cobb Angle
• Severe - > 45 Cobb Angle

Surgical treatment is usually recommended when there is progression of the curve and when the curve is above 50 degrees.

Who does scoliosis affect?

Idiopathic scoliosis is divided into three age categories based upon the initial presentation of the curve.

Infantile idiopathic scoliosis presents between the ages of birth and two years old, juvenile idiopathic scoliosis presents between the ages of three and 10 years old, and adolescent idiopathic scoliosis presents between the ages of 11 and 17 years of age.

Another difference between the three types of scoliosis is that infantile and juvenile scoliosis have a higher association with other spinal abnormalities, such as tumors, syringomyelia (a large tube or cyst in the spinal cord), and descending of the cerebellum into the spinal canal. These disorders require additional and different treatment from adolescent idiopathic scoliosis.

Three to five percent of people have curves greater than 10 degrees but only 0.2-0.3% require treatment. There is a difference between females and males with AIS. In curves between 11-20 degrees there are more females with AIS than males. As the curves get bigger (greater than 20 degrees) so do the numbers of females with AIS compared to males. Also female curves increase or progress more often than in males.

Adolescent idiopathic scoliosis is usually first identified by a family member, school screening or paediatric or family physician. Dr Balakumar believes the key to successful treatment is early identification and early referral to an orthopaedic spine surgeon. It is tempting to see chiropractors and other NON medical specialists. However, they will not be able to offer you expert opinion and early treatment to prevent progression.

Because AIS is usually painless, a fullness or prominence of the back is noted, especially with bending forward. This prominence or rib hump can be measured using a scoliometer (a leveling device placed over the spine). The scoliometer measures the angle of trunk rotation at the apex or peak of the prominence. Once the patient is referred to a scoliosis specialist and after a thorough history and physical examination, radiographs or X-rays are taken. These X-rays are done while the patient is standing and include front, side and bending positions.

How is Adolescent Idiopathic Scoliosis (AIS) diagnosed?

What are the signs and symptoms?

The symptoms and signs of adolescent idiopathic scoliosis included shoulder asymmetry (one shoulder higher than the other) waist line asymmetry or tilt, trunk shift (comparing the chest or torso to the pelvis),and limb length inequality. AIS is a painless deformity and the patients have no weakness or movement problems.

Symptoms or signs that alert the physician that another diagnosis should be considered include: other structural abnormalities of the spine found on X-ray, excessive kyphosis (forward curvature of the spine), juvenile onset scoliosis, infantile onset scoliosis, rapid curve progression, associated syndromes or lower extremity deformities, back pain and neurologic signs or symptoms.

How are curves measured?

While the patient is standing, X-rays are taken with the patient standing in the anterior/posterior plane, the lateral plane, side bending, fulcrum bend and push prone. During the push prone X-ray, the patient is placed on the radiograph table in the prone (on their belly) position while manual pressure is applied to the apex of the thoracic curve at the same time the pelvis and shoulders are stabilized. The side bending X-rays help to determine the flexibility of the curves.This is only done if there is surgery contemplated. A Cobb angle is used to measure the curve; the major curve is the curve with the largest Cobb angle.

Minor curves are treated differently depending on their flexibility. Patients can present with a variety of curve patterns depending on the location of the curve, the magnitude of the curve and curve flexibility. Follow-up X-rays monitor the curves and their angles, and will alert the physician to progression of the scoliosis.

How is progression monitored?

Progression of scoliosis depends on the curve magnitude and the skeletal maturity of the patient at the time it is identified. The smaller the curve and the more fully grown the patient is, the less likely the scoliosis is to increase.  The difficulty is trying to predict when a patient is going to go through a growth spurt.Your health care provider will consider a number of growth factors (ie, growth of the hip socket and iliac crest, when a girl has begun menstruation) to assign a Risser sign number.

The smaller the Risser sign number (0-5), the more growth is remaining. The most accurate predictor of growth remaining is peak height velocity (PHV, the maximum height reached by age 7).

Generally, curves less than 30 degrees at skeletal maturity are not likely to progress, compared to curves greater than 50 degrees which will generally continue to progress at a rate of 1 degree a year.

Treatment of adolescent idiopathic scoliosis (AIS)

Treatment of adolescent idiopathic scoliosis depends on the size and location of the curve and the growth remaining of the patient.

There are three types of treatment in AIS:

• Observation
• Bracing
• Surgery

In general, patients are observed for progression with curves between 0-20 degrees. These patients are followed periodically with radiographs to note any curve progression.

For patients with curves of 20-40 degrees a brace is used if progression is documented and the patient has substantial growth remaining. Bracing will not correct the curve but might prevent curve progression. Successful use of a brace is dependent on the amount of time the patient wears the brace. The brace is worn until growth is complete and is worn between 16 and 23 hours a day.

Surgery is usually indicated for 50° curves, 40° curves in a skeletally immature patients, curves that progress despite bracing, and “unacceptable”(to the patient) deformity.

Curve in Degrees - Treatment

• 0-20 : Observe for progression
• 20-25 : Brace if progression documented, and substantial growth remaining
• 25-30 : Brace if progressive and growth remains
• 30-40 : Brace if growth remains
• 40-45 : Brace if growth remains vs. surgery
• >50 : Surgery

What surgical treatments are available for scoliosis?

Depending on curve type, curve flexibility and location of cure, surgical correction of scoliosis can be approached in many ways.

Fusion surgery is the procedure of choice. The vertebra are fused together with bone either anteriorly (from the front of the spine), posteriorly (in the back of the spine) or a combination. instrumentation is used to allow the fusion to heal and help hold the correction of the scoliosis. Instrumentation includes: screws, rods, hooks, and wires.

• Adolescent Idiopathic Scoliosis - Pre-Operative Adolescent Idiopathic Scoliosis - Pre-Operative
• Adolescent Idiopathic Scoliosis - Pre-Operative Adolescent Idiopathic Scoliosis - Pre-Operative
• Adolescent Idiopathic Scoliosis - Post-Operative Adolescent Idiopathic Scoliosis - Post-Operative
• Adolescent Idiopathic Scoliosis - Post-Operative Adolescent Idiopathic Scoliosis - Post-Operative
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Long-term follow-up is difficult to assess because of the large variety of curves, flexibility of curves and progression of curves. The vast majority of patients who have scoliosis and are treated with observation, a brace or surgery, lead productive lives and are not limited by their scoliosis or its treatment.

Dr Balakumar usually perform posterior instrument fusion. It is recognised by Medicare as one of the biggest and most complicated surgeries. Long term analysis shows that 95% of patients are very satisfied they had the operation and would do it again. However the risk profile and recovery is significant.

Risks

First the bad news. The risks are a 1/1000 risk of permanent paralysis. This means that you may never walk again. There is 1/100 risk of infection. If this happens it is a serious complication, but it can be cured with repeat surgery and antibiotics. There is a risk of rod breakage, screw breakage and implant failure. There are abdominal risks such as pancreatitis, bowel obstruction or loss of blood supply to bowel. All of these are exceedingly rare. There is also risks of breathing problems including air leakage in the lung, despite pure posterior surgery.

In the long-term, the unfused segments of the spine may take a life of their own and cause other curves to form. Dr Balakumar will monitor for this in the long term.  There is risk of some portions of the spine not fusing and this can be asymptomatic.

Recovery

For the most part, most children and adolescents will spend up to one week in hospital. There is six week period of school leave and three months before jogging or bending. After six months most kids can return to school; 95% will never have any further problems. Pain is uncommon but the cross links between the rods can cause annoyance and is often felt under the skin. Sometimes pain can occur above the top of the spine.

To avoid complications, Dr Balakumar will use spinal monitoring and the correction of the spine will be dependent on how much correction the spinal cord can handle safely. Post operatively the neurology in the child is checked by Dr Balakumar and his team.

Dr Balakumar performs scoliosis surgery at the Royal Children’s Hospital in Melbourne.  

• View the related article on Scoliosis