Orthoses

Scoliosis: bracing, tethering (VBT) or spinal fusion?

Vietnam performed its first vertebral body tethering (VBT) in October 2026. Bracing, VBT and spinal fusion compared: pros and cons, re-operation rates and the evidence, to help families decide with their doctor.

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Scoliosis: bracing, tethering (VBT) or spinal fusion?

For a growing child, a corrective brace is still the first and safest choice. Surgery is considered only when the brace is no longer effective enough. In that case, spinal fusion remains the standard, while vertebral body tethering (VBT) is a newer technique: promising, but with many risks.

In October 2026, the 108 Military Central Hospital announced the first VBT in Vietnam, in a 12-year-old girl. Many parents are now wondering whether to choose this method. This article explains the three treatment options, their pros and cons and the scientific evidence for each, so families can decide together with the doctor.

Adolescent idiopathic scoliosis is a sideways curve of the spine with rotation of the vertebrae, usually appearing from age 10 until growth ends. Its severity is measured as the Cobb angle on an X-ray. The curve can worsen quickly during the growth spurt, so early detection and treatment are decisive.

The three options at a glance

Criterion	Corrective brace	Tethering (VBT)	Spinal fusion (screws + rods)
Surgery?	No	Yes, through the side of the chest or abdomen	Yes, major surgery from the back
Goal	Reduce the curve while the child grows and avoid surgery	Use cord tension and growth to correct the curve gradually	Correct and permanently fix the curved segment
Spinal motion	Preserved	Mostly preserved	Lost in the fused segment
Predictability of the result	Good if worn for enough hours and the brace is well made	Hard to predict; over- or under-correction possible	Most stable; the gold standard
Re-operation rate	Not applicable	About 15–16%	About 1–2%
Scientific evidence	Large randomised trial (BrAIST, 2013)	Mainly retrospective studies, follow-up under 10 years	Decades of experience
In Vietnam	Widely available	First case only (10/2026)	Routinely performed
Best suited to	Growing children, Cobb angle about 20–50°	Growing children who did not respond to bracing, carefully selected	Curves over 50° after skeletal maturity, or progressing despite treatment

1. The corrective brace: the first choice

Bracing is the only method shown in a randomised controlled trial to help children avoid surgery. Its biggest advantages are that it is non-invasive, keeps spinal motion and leaves no surgical scar.

Principle: the brace applies deliberate pressure areas and spaces to the trunk to push the spine towards a straighter position. While the child is still growing, the spine is guided to grow in the corrected position.

A brace must be made for each person. Every curve has a different shape, so the brace must be designed and made by an orthotic engineer for each patient. A good brace combines several correction principles (Boston, Chêneau, Milwaukee, night-time overcorrection) rather than following one school. The curve is corrected by hand during plaster casting, then the brace is vacuum-formed from thermoplastic. A 3D scanner or software is only a support tool and cannot replace the maker’s skill.

How to read this image: the two photos on the left show plaster casting for a brace at our clinic. The patient stands in a traction frame while the orthotic engineer applies corrective force by hand as the plaster sets, so the curve is already corrected on the mould. On the right is a full-spine X-ray used to measure the Cobb angle and plan the correction. The patient-name line on the film has been masked. Image source: dungcuchinhhinh.vn.

The evidence for bracing

The BrAIST trial (New England Journal of Medicine, 2013) followed 242 high-risk children. Here “success” means the curve did not progress to the surgical threshold (50°):

72% of braced children succeeded, versus 48% in the observation group.
The more hours worn, the better: children who wore the brace more than 13 hours a day on average had a success rate of 90–93%.
The trial was stopped early because the benefit for the braced group was clear.

The Cochrane systematic review (Negrini et al., 2015) included 7 studies with 662 adolescents; all showed that bracing prevents curve progression. A rigid brace increased the success rate 1.79-fold compared with observation in 20–40° Cobb curves; rigid braces were more effective than soft braces; very rigid braces still worked in curves over 45° Cobb. No significant harm was recorded: quality of life, back pain and psychological status after 16 years did not differ from those not braced. Cochrane rated the quality of evidence moderate to very low, mainly because randomised trials are difficult when many parents do not agree to random allocation.

The international SOSORT 2016 guideline recommends bracing for growing children with curves from about 20° Cobb, delivered by a trained team of doctor, orthotic engineer and physiotherapist.

A newer trend: custom, high-correction braces

Braces made for each individual that strongly correct the curve as soon as they are worn are now the main trend. There is less evidence for them than for traditional braces, mostly retrospective follow-up studies, but the corrections achieved are very high.

The in-brace correction (how much the Cobb angle is reduced, in percent, on an X-ray taken while wearing the brace) predicts the final outcome:

A study of 449 patients (Aulisa et al., Children, 2022): children with much growth remaining and good in-brace correction had a success rate of 87%. In this study “success” meant the curve decreased by more than 10° Cobb, not just stayed the same.
The literature suggests an in-brace correction of at least 30–50%. With Chêneau-type braces, an in-brace correction over 40% is clearly associated with good outcomes.
Rigo-Chêneau-type braces assessed by the standard Scoliosis Research Society (SRS) criteria: average in-brace correction 53.5%, up to 77% for lumbar curves; only 1 of 32 patients needed surgery.
By contrast, a US study found that 76% of conventional braces had an in-brace correction below 30%, under the recommended level. The quality of brace design and manufacture determines treatment effectiveness.

Not just holding, but reducing the curve

With a high-correction brace worn for enough hours, many children have a real reduction in curve after the brace is removed:

High-correction Chêneau-type brace (JMIR Rehabilitation and Assistive Technologies, 2024): 33 children aged 12 on average, initial curve 33.6° Cobb. Average in-brace correction 80%. After complete weaning, counted by children: 78.8% had a smaller curve, 21.2% were stable, and none got worse.
Severe curves over 45° (The Spine Journal, 2011): 28 growing children who refused surgery, average curve 49.4°. After about 4 years of full-time rigid bracing combined with exercise, 71% of the children improved and only 2 remained above 50° Cobb.
Curves of 40° or more (The Open Orthopaedics Journal, 2017): 25 children with an average initial curve of 49°. Chêneau-type bracing succeeded in 92% of the children.

These studies are small and mostly observational, not randomised, and each defines “success” differently, so their figures cannot be compared directly with each other. Still, they consistently show that the quality of brace correction decides whether a child merely “does not get worse” or truly improves.

Note: “success” in BrAIST only means the curve stayed below 50°. Our goal is higher: a real reduction of the curve to below 30° at skeletal maturity, because a 45° curve can still worsen in adulthood.

Indications by Cobb angle (growing children)

Cobb angle	Approach
Under 20°	Exercise is worthwhile. Consider a rigid night brace if there are unfavourable factors such as a curve that has progressed or pelvic imbalance
20–50°	A corrective brace is essential, combined with exercise
Over 50°, still growing	Can still be pulled back with a brace if the in-brace correction is over 50%
Over 50°, skeletally mature	Consider surgery

Limitations: the child must wear the brace many hours a day, continuously until growth ends. Results depend heavily on the child’s cooperation and the quality of the brace. The brace must be checked and adjusted regularly as the child grows.

2. Vertebral body tethering (VBT): a newer technique with many risks

VBT preserves spinal motion, but cord breakage and re-operation are far more common than with fusion, and there are no long-term data.

How it is done: the surgeon operates through the side of the chest or abdomen, often thoracoscopically. Screws are placed in the vertebral bodies on the convex side of the curve and connected with a strong polyethylene cord. Tensioning the cord corrects the curve during surgery. Afterwards, the cord restrains growth on the convex side while the concave side keeps growing, so the curve continues to correct as the child grows.

Advantages of VBT

No fusion; most of the motion of the operated segment is preserved.
Less blood loss and faster recovery than fusion.
If it fails, conversion to fusion is still possible.

Risks and scientific evidence

Cord breakage is the most common complication. A meta-analysis of 16 studies (Spine Deformity, 2023) found an overall complication rate of 23%, with cord breakage at 21.9%. Recent reports show about 50% of patients have a broken cord after 36 months.
About half of the children with a broken cord have a worsening curve (an international study of 84 patients, Pediatric Spine Study Group).
More re-operations: a multicentre Harms Study Group study (122 matched pairs) found that 16% of VBT patients needed further surgery versus 1.3% after fusion. A 2025 meta-analysis found about a 5.5-fold higher risk of re-operation.
Overcorrection can occur, reversing the curve and requiring surgery to release the cord.
The effect fades over time: a US group found the share of patients keeping the curve under 30° fell from 74% to 64% after an average of 5.7 years.
The first VBT device was approved by the US FDA in 2019 under a humanitarian device exemption, based on data from only 57 patients. Long-term follow-up studies are expected to finish in 2029.

Who it suits: children with much growth remaining (ideally Sanders 3 or below), with one flexible curve, who were braced without success. Curves of 65° or more are usually considered too large for VBT.

3. Spinal fusion (screws + rods): the gold standard when surgery is needed

When surgery is needed, posterior spinal fusion remains the standard, giving stable results and the fewest re-operations. The price is permanent loss of motion in the fused segment.

How it is done: the surgeon operates from the back, inserts screws into the vertebrae and connects them with two metal rods to correct the curve. Bone graft then lets the vertebrae fuse into one solid block, fixing the result long term.

Pros and cons of fusion

Advantage: the strongest and most reliable correction; meta-analyses show fusion gives better spinal alignment, fewer complications and fewer re-operations than VBT.
Advantage: decades of experience, a standardised technique performed widely in Vietnam; it does not depend on whether the child is still growing.
Disadvantage: the fused segment loses all motion between the vertebrae; the longer the fusion, the less flexible the spine.
Disadvantage: it is major, lengthy surgery with possible heavy blood loss and need for transfusion; the result is irreversible.
Evidence comparing surgery with non-surgical care is lacking: the 2015 Cochrane review found no trial comparing fusion with non-surgical treatment in curves over 45°, so long-term benefits and harms cannot yet be concluded.

Who it suits: curves over 50° after skeletal maturity, or curves that keep progressing despite correct bracing.

Which option should you choose?

The sensible order for a growing child is: brace first, surgery later. Among surgical methods, fusion is the standard; VBT is only for a small number of carefully selected cases.

Detect early: check the back of children from age 9–10: uneven shoulders, a prominent shoulder blade, uneven waist, pelvic imbalance. If in doubt, take a full-spine X-ray to measure the Cobb angle and assess skeletal maturity.
Treat conservatively at the right level: under 20°, exercise and monitoring, with a night brace considered if there are unfavourable factors; from 20°, a custom corrective brace combined with exercise.
Choose a high-correction brace: ask for an in-brace X-ray to know the in-brace correction in percent. The target should be 40–50% or more.
Wear it for enough hours and attend regular reviews: the effect rises clearly with hours of wear; the brace must be adjusted as the child grows.
Consider surgery only when the curve keeps progressing despite correct bracing, or exceeds 50° after skeletal maturity.

If the doctor suggests VBT, ask

Has my child really failed with a well-correcting brace?
Is my child’s skeletal maturity (Sanders, Risser) suitable for VBT?
What happens if the cord breaks or the curve is overcorrected? What would re-operation cost?
How many VBT operations has the hospital performed, and for how long have they been followed? If fusion were chosen, how many vertebrae would be fused?

If your child has been diagnosed with scoliosis or has been offered surgery, bring the X-rays for an examination, assessment of skeletal maturity and advice on a custom corrective brace. Hotline +84 985 211 888. This article is for health education and does not replace an in-person examination.

References

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