Teenage or adolescent idiopathic scoliosis (AIS) affects children between the ages of 10 and 18. The incidence rate is about 3–4% among school-going children.

The scoliosis usually worsens during the rapid growth period of the patient. While most scoliosis curves stop progressing at the time of skeletal maturity, some, especially curves greater than 50 degrees, continue to progress during adulthood.

“Idiopathic” means that the condition has no identifiable causes although there may be some genetic basis for AIS. Approximately 30% of AIS patients have some family history of scoliosis.

Although idiopathic scoliosis occurs most often in the teenage years, it can also present in younger age groups, i.e. 9 years and younger. These idiopathic scoliosis cases are also classified as early onset scoliosis (EOS).

Apart from idiopathic cases, EOS also encompasses other rarer forms of scoliosis, e.g. congenital scoliosis (present at birth due to abnormal development of the vertebra), neuromuscular scoliosis (e.g. spinal muscular atrophy), and syndromic scoliosis (e.g. neurofibromatosis). Scoliosis in EOS cases has a greater tendency to worsen compared to adolescent idiopathic scoliosis. Special considerations for surgical treatment are required, as the child has many years of growth remaining.

Common Features of Adolescent Idiopathic Scoliosis

Patients with AIS typically have no pain or neurologic abnormalities (e.g. weakness of the legs).

When viewed from the back, one shoulder may appear higher than the other shoulder (Figure 1).

When the patient bends forward, there may be a prominence on the back due to rotation of the scoliosis.

A shift of the body to the right or the left can occur especially when there is a single primary curve in the back of the spine without a secondary curve to help balance the spine. This may appear as waistline asymmetry in which one hip appears to be higher than the other and may result in one leg appearing longer than the other leg.

Uneven waist and hip, where one hip is higher than the other.

Patients may sometimes experience some back pain, typically in the low back. Much of the low back pain is probably due to not having proper core abdominal and back strength, or hamstring flexibility.

A back view of a boy with curved spinal and uneven shoulder, which are the symptoms of adolescent idiopathic scoliosis

Figure 1

Assessment and Diagnosis

Measurement of the rotation of the spine.

Assessment of ligament laxity and neurological integrity.

X-rays are performed to measure the scoliosis curve. Any spinal curve greater than 10 degrees is considered scoliosis.

The Risser grading system is used to determine a child’s skeletal maturity (how much growth is left) on the pelvis, which correlates with how much spine growth is left.

MRI of the whole spine may be needed in some cases to rule out structural issues with the spinal cord that can affect the progression of scoliosis.

Treatment Options

Observation

Regular follow-up checks

Bracing

Bracing is used for patients whose curves are more than 25 degrees and are still skeletally immature.

If there is a strong family history of scoliosis, the threshold to start bracing may be lowered to 20 degrees.

The role of a brace is to halt or slow progression of the curve, hopefully avoiding surgery.

The effectiveness of bracing correlates with the duration the brace is worn.

It is advised that patients wear their braces for at least 16 hours a day.

Sometimes, physiotherapy scoliosis-specific exercises may be prescribed in conjunction with bracing. This may provide some physical benefits such as core strengthening and symptom relief.

A back view of a girl using the hard bracing treatment method for adolescent idiopathic scoliosis

Hard Brace

Surgery

Surgical treatment is recommended for patients whose curves are greater than 40 degrees while still at the growth stage, or greater than 50 degrees when growth has stopped.

The goals of scoliosis surgery are to prevent curve progression, obtain some curve correction, as well as restore or maintain spinal balance.

Titanium implants are used to correct the scoliosis deformity and hold the spine in the corrected position until the instrumented spinal segments fuse as one entity.

The hospital stay is usually 5–7 days.

One to two days after surgery, the patient will gradually get up and out of bed, followed by walking with the assistance of a physiotherapist. Breathing exercises will also be started after surgery to prevent fever and lung complications from occurring.

Most patients can return to school after 3 to 4 weeks, but they have to be temporarily excused from physical exercises. Swimming can be resumed about 2 months after surgery. However, high-impact sporting activities can only be resumed about one year after surgery.

Types of Surgery

Fusion Surgery

Fusion is the most commonly adopted surgical method of choice, where the vertebrae are joined together by bone implanted during surgery and held together by titanium screws and rods.

The surgery can be performed either from the back or the side of the body.

For the back approach, a straight incision is made along the midline of the back.

An x-ray of an after spinal fusion surgery back view

Double Curves (i)

An x-ray of an after spinal fusion surgery side view

Double Curves (ii)

For the side approach, an incision is made through the side of the spine. This side approach is an option in cases where a single thoracic curve or a single lumbar curve is being surgically treated.

An x-ray of a single thoracic spine curve after surgery

Single Thoracic Curve

An x-ray of a single lumbar spine curve after surgery

Single Lumbar Curve

Non-fusion Surgery

Apifix

For some adolescent idiopathic scoliosis cases, there may be a role for non-fusion Apifix surgery if the spinal curvatures are less than 60 degrees and are also flexible.

The surgery involves a dynamic deformity correction system which acts as an internal brace implanted unilaterally on the concave side of the curve.

The operating time is significantly shorter than traditional scoliosis fusion surgery. This translates to a shorter hospital stay and shorter downtime before resuming daily activities.

Non-fusion Apifix Surgery

Growing Rods

Growing rods are used in the surgical treatment of Early Onset Scoliosis patients, and the device can be adjusted in tandem with the growth of the child.

A final surgery involving fusion will be performed to correct and stabilise the scoliosis.

Non-fusion Surgery using Growing Rods

What Happens if Scoliosis is Left Untreated?

Moderate to severe scoliosis that is left untreated can lead to pain and increasing spine deformity, as well as potential heart and lung damage. It may also have a profound psychological impact on the patient due to the physical appearance.

When to Consult a Spine Specialist

Adolescent idiopathic scoliosis may progress during growth and can lead to worsening spinal deformity if left untreated. Early assessment by a spine specialist may help determine whether observation, bracing, or scoliosis surgery is appropriate based on the severity of the curve and remaining skeletal growth.

	Dr Hee Hwan Tak Orthopaedic Surgeon & Spine Specialist MBBS (Singapore) \| FRCS (Edinburgh) \| FRCS (Glasgow) \| FAMS (Ortho)
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Teenage or Adolescent Idiopathic Scoliosis