Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis is a sideways curve of the spine that shows up in the teenage years, with no single known cause. Most curves are small and stay small, and many only need regular check-ups. A brace helps some children, and only a few need surgery, which most teenagers recover from well.

Reviewed by Dr. Kshitij Chaudhary — Last reviewed October 2026

What is adolescent idiopathic scoliosis?

Scoliosis is a sideways curve of the spine. The bones also twist a little, which is why one shoulder, hip or side of the ribcage can look higher or stick out more. We measure the curve on an X-ray as the Cobb angle, and more than 10 degrees counts as scoliosis. "Idiopathic" means we don't know the exact cause. "Adolescent" means it starts from around age 10, when growth speeds up.

What causes it, and who gets it?

It runs in families. About 3 in 10 teenagers with scoliosis have a relative with it, though it can skip a generation. Nothing you or your child did caused it, and heavy school bags, posture, sport and diet don't cause scoliosis.

About 2 to 3 in every 100 adolescents have it. Boys and girls get small curves equally often, but girls are five to eight times more likely to have a curve that grows. Scoliosis linked to a nerve or muscle condition is a different problem, covered on our Neuromuscular Scoliosis page.

How serious is it?

For most families, not very. Most curves are small, they rarely hurt in teenagers, and scoliosis almost never needs urgent action. We watch and treat curves to stop them growing big enough to cause trouble in adult life. Very large curves, over about 70 to 80 degrees, can affect breathing and cause back pain.

What are the signs?

Parents, teachers and coaches usually notice a curved spine first, because scoliosis rarely hurts.

• One shoulder or shoulder blade higher, or sticking out more
• One hip higher, or an uneven waist
• The ribcage or trunk shifted to one side
• Clothes hanging unevenly
• One side of the back looking higher when your child bends forward

Early curves can look almost normal, so nobody has missed anything. If you notice any of these, book a visit.

How is it diagnosed?

We examine your child's back, check height and nerve function, and do the forward bend test. Your child bends at the waist so we can see any twist in the ribs or lower back. The diagnosis is confirmed on a standing X-ray of the whole spine.

A typical curve doesn't need an MRI. We recommend one if the pattern is unusual, if there is pain or any nerve symptom, or before surgery.

Will the curve get worse?

Most small curves stay small. Two things matter most: how big the curve is now, and how much growing your child has left. The risk is highest during the growth spurt, when a curve that is going to progress can grow by 1 to 2 degrees a month.

We judge how much growth is left from height, puberty, the Risser sign (a cap of bone along the top of the pelvis on X-ray) and sometimes a hand X-ray. Once growth is over, curves under 40 degrees rarely get worse.

What are the treatment options?

There are three paths: watch, brace or operate. This table is a general guide. We also weigh the curve pattern and how fast it's changing.

Observation means an examination and X-ray every 4 to 12 months, depending on how much growing is left.

Does a scoliosis brace work?

Often, yes. A brace is a rigid plastic shell worn under clothes. We usually prescribe a custom TLSO or a Boston brace, fitted in Mumbai. Its job is to stop the curve growing, not to straighten it for good.

In the BrAIST trial, published in the New England Journal of Medicine, about 72 in 100 braced children did not reach a 50-degree curve, compared with 48 in 100 who were only watched. The more hours a day the brace was worn, the better it worked. Sport is fine, and it doesn't make scoliosis worse.

When is surgery needed?

Surgery is considered when a curve in the upper or mid-back reaches about 45 to 50 degrees, or a lower-back curve reaches about 40 degrees. It's also considered when a brace hasn't held a growing curve, or when growth has finished and the curve is over about 50 degrees, because those curves tend to keep growing slowly into adult life. Most children never need an operation.

If you're unsure about the advice you've been given, you're welcome to send your scans and reports for a second opinion.

What does surgery involve?

The usual operation is a posterior spinal fusion. Through a cut along the back, we place screws into the vertebrae and attach rods that straighten the spine as far as is safe. Bone graft then lets the bones fuse into one solid column over 6 to 12 months. The aim is to stop the curve getting worse, not to make the spine perfectly straight.

In selected growing children, we offer vertebral body tethering, which keeps more movement. Throughout either operation, the spinal cord is monitored, which significantly lowers the risk of nerve problems. Every operation has risks, and we go through them with you in plain terms.

What is recovery like?

Most teenagers stay in hospital 3 to 7 days and are up and walking within a day. They go back to school 3 to 6 weeks after surgery and feel back to normal by about 6 weeks. Contact sport, heavy lifting and hard twisting wait until the bone has fused. Most are free of all limits by one year.

Could we have prevented it?

No. It's genetic, and nothing your child or you did made it happen. What helps is finding it early and following the curve, so treatment starts before it's large.

Questions to ask your doctor

• How big is the curve, and how much growing is left?
• How likely is it to get worse?
• What do you recommend now, and why?
• If a brace, how many hours a day, and for how long?
• If surgery, which operation, and what are the risks?
• What should we watch for between visits?

Treatments we offer for this

Observation and regular follow-up, bracing (custom TLSO or Boston brace), physiotherapy, scoliosis correction surgery (posterior spinal fusion) and vertebral body tethering in selected children.

About Dr. Kshitij Chaudhary

This page was written by Dr. Kshitij Chaudhary, a fellowship-trained spine surgeon at P.D. Hinduja Hospital, Mumbai, trained in complex spine surgery at Harvard Medical School (Beth Israel Deaconess) and the Twin Cities Spine Center, Minneapolis. Learn more about Dr. Chaudhary →

This information is for general education and does not replace a consultation with your doctor.