Watching your child grow up healthy and strong is every parent’s wish. So, when a diagnosis of scoliosis – a curvature of the spine – enters the picture, it’s natural to feel concerned and seek out the best possible treatment. Traditionally, severe scoliosis in children and adolescents was treated with a spinal fusion surgery that corrects the curve but also permanently stiffens that part of the spine. Today, there’s a novel option available for some patients: Vertebral Body Tethering (VBT). VBT is an innovative, less invasive surgical technique for scoliosis that aims to correct the spinal curve while preserving spine flexibility and growth. Our pediatric orthopedic practice is proud to offer this cutting-edge treatment for carefully selected patients. In this educational blog, we’ll explain what VBT is, who it’s for, how it differs from traditional fusion, and what outcomes you can expect. We’ll maintain an empathetic, family-friendly tone – we know any surgery can be intimidating, but knowledge can empower you to make the best decision for your child. Emphasizing successful outcomes and careful patient selection, we hope to give you a clear picture of whether VBT might be the right choice for your child’s scoliosis.

Understanding Scoliosis in Children

Scoliosis is a condition where the spine curves sideways in an “S” or “C” shape, often accompanied by some rotation of the vertebrae. In children and teens, the most common form is Adolescent Idiopathic Scoliosis (AIS) – idiopathic meaning we don’t know the exact cause. AIS typically becomes noticeable during the pre-teen or teen years (10-15 years old), often during a growth spurt. Curves can range from mild (10-25°) which usually just need monitoring, to moderate (25-45°) where bracing might be recommended, to severe (45° and above) where surgery is often considered. Untreated severe scoliosis can progress and potentially lead to pain, cosmetic concerns (uneven shoulders or waist), and in very large curves (70-80°+), even affect lung function. For decades, the standard surgical treatment for scoliosis above ~45-50° in a growing child has been posterior spinal fusion. This involves attaching metal rods and screws to the spine from the back and fusing the curved vertebrae together so they heal into one solid bone. Fusion is very effective at halting curve progression and improving alignment, but it eliminates motion in that fused segment of the spine. In a 14-year-old near the end of growth, losing a bit of motion in, say, the thoracic spine is generally well tolerated. However, in a younger child or a very active teen, fusion raises concerns about flexibility (for instance, some athletes or dancers worry about stiffness). Fusion in very young patients (<10 years) also stops growth in that segment, which can be problematic as they still have a lot of growth left in the spine and chest; that’s why in little kids, growing rod strategies were developed to delay fusion. Enter Vertebral Body Tethering, an approach that tries to address these concerns by correcting the curve without fusing the bones. It’s often described as a form of “growth modulation.” Instead of locking the spine in place, VBT uses a strong but flexible cord (the tether) to partially restrict growth on the curved side of the spine, allowing the other side to catch up and straighten the spine over time. Think of it like braces on teeth – a constant gentle pressure guiding growth.

What is Vertebral Body Tethering and How Does it Work?

Vertebral Body Tethering (VBT) is a surgical procedure performed through the side of the chest/abdomen (an anterior approach). During the surgery, the patient is usually positioned on their side. The surgeon makes small incisions (often thoracoscopically, meaning using a scope and tiny openings) to access the front of the spine. Screws are placed into the vertebral bodies (the thick, round front parts of each spine bone) along the outside of the curve, and a flexible polyethylene tether (like a strong cord) is attached to these screws. When the tether is tightened, it compresses the screws on the convex (outer) side of the curve, partially straightening the spine immediately and – importantly – creating a gentle pull that will modulate growth. The concept is based on a principle called the Hueter-Volkmann law: growth of bone slows under compression and speeds up when tension is reduced. By tightening the tether on the outer side of the curve, growth on that side slows, while the inner side of the curve (under less tension) continues to grow normally or faster, thus over time the curve corrects itself as the child grows. One huge advantage is that the spine’s natural movement and flexibility are preserved because no fusion is done. The tether acts sort of like an “internal brace,” guiding the spine rather than rigidly locking it. This means children can maintain a greater range of motion. They can typically bend, twist, and participate in sports more freely after recovery compared to a fusion patient (who has certain movement restrictions). VBT patients, after healing, often return to activities like gymnastics, swimming, and other sports without the worry of hardware limiting their motion. Because tethering relies on growth, it’s not a quick overnight fix – it achieves some immediate correction during surgery (often the curve can be partially straightened on the operating table), but then the curve continues to improve as the child grows over the next 1-2 years, using that remaining growth to further straighten the spine. Studies have shown that on average, VBT can cut the spinal curvature roughly in half over a couple of years of growth. For example, a 50° curve might be brought down to ~25° or less by two years post-op, which is a significant improvement. In many cases, this means avoiding the need for a fusion entirely. In fact, a systematic review and meta-analysis in 2023 concluded that VBT is effective at reducing scoliotic curves and preventing spinal fusion in the majority of patients. Another benefit: unlike bracing, which only aims to stop progression, tethering actually corrects the curve and guides it to straighter growth. And unlike growing rods (which require repeat surgeries to lengthen), modern tether devices allow the spine to grow without the need for periodic surgical adjustments – the tether just naturally adjusts tension as the spine lengthens (though in some cases, too much growth can lead to overcorrection, more on that later).

Who is a Candidate for VBT? (Patient Selection)

Careful patient selection is absolutely key for VBT’s success. Not every child with scoliosis will be a candidate. Based on current FDA guidelines and clinical practice, ideal candidates have the following general profile:

Diagnosis: VBT is generally indicated for idiopathic scoliosis (scoliosis not caused by an underlying condition). It is not typically used for scoliosis due to neuromuscular disorders (like cerebral palsy) or congenital vertebral anomalies, because those curves behave differently. So, a child with adolescent idiopathic scoliosis (AIS) is the main group considered. If a child has something like Marfan syndrome or other connective tissue issues, caution is used – there have been some cases done, but idiopathic AIS remains the primary indication.

Curve Size: Usually moderate curves between 40° and 65° (somewhere in that ballpark). Below ~40°, a brace is often sufficient and surgery is not indicated. Above ~65-70°, the curve is very stiff and the tether might not be strong enough to correct or control it. In large curves, fusion might still be the safer bet to truly straighten the spine. Also, the bigger the curve, the more growth would be needed to correct it.

Growth Remaining: The child should have significant growth potential left, but not too much. This typically means children who are around 10 to 14 years old, though there’s no strict age cutoff. More formally, surgeons assess bone age and skeletal maturity (for example, using the Risser sign on X-rays or hand bone age). If a child is almost done growing, VBT might not make sense because there’s little growth left to modulate – a fusion or just observation might be considered instead. On the flip side, if a child is very young (8-9 years old) with a lot of growth left, tethering could overcorrect (the tether keeps working and might create a curve in the opposite direction if they outgrow it).

Flexibility of the Curve: VBT works best if the curve is flexible (meaning it can be partially straightened when the child bends or when traction is applied under anesthesia). If X-rays taken with the child bending to the side show the curve almost straightens, that’s a good sign for tethering. Very rigid curves that don’t move much on bending films may not correct enough with tether alone.

Location of Curve: Initially, VBT was primarily done for thoracic curves (upper and mid-back). Now some surgeons also tether lumbar curves or thoracolumbar. The technique can be applied to most of the spine except the very top and very bottom. If a child has a double curve (S-curve), sometimes both curves can be tethered in one surgery (an upper and a lower tether). In other cases, they might tether the main curve and accept a smaller residual curve above or below.

General Health: The child should be healthy enough for surgery. VBT is done under general anesthesia, typically lasting 3-4 hours. It’s moderately invasive (though less so than a full fusion). We ensure the heart and lungs are in good shape.

Benefits of VBT Compared to Traditional Fusion

VBT offers several unique benefits:

Preservation of Motion: By not fusing the vertebrae, the spine retains its natural movement. This can be especially important for flexibility in sports, dance, or just day-to-day comfort. Children can bend their spine because only a tether – not a solid bone fusion – is limiting the curve.

Continued Growth: The tether allows the front of the spine to continue growing taller. This is great for overall height (every bit counts when we’re dealing with kids!). It’s also beneficial for thoracic volume – allowing the rib cage to expand as the child grows, which is better for lung development.

Less Invasive Incisions: VBT is often done through several small incisions on the side, using endoscopic tools. There is no long incision down the back, and muscle disruption is less. This can mean a faster initial recovery and possibly less scarring.

No Need for Repeat Lengthening Surgeries: Unlike growing rods (used in very young kids), which require surgery every 6 months to lengthen, the tether “grows with the child” without repeated operations.

Psychological Benefit: Some teens feel reassured that their spine isn’t fused solid. They like the idea that their back is still “normal” in terms of movement.

What to Expect: Outcomes & Considerations

Parents often ask, “How effective is VBT, and what are the risks?” The data so far are encouraging but do come with some caution. Success rates in experienced centers show that the majority of patients achieve a good curve correction and do not require a follow-up fusion. That’s a very promising statistic for an appropriately selected group. However, VBT is not guaranteed to “cure” scoliosis forever – the goal is to manage it without fusion, but long-term follow up is ongoing.

Choosing the Right Care for Scoliosis: Our Experience with VBT

Our clinic was among the early adopters of Vertebral Body Tethering, and we have built substantial experience with this technique. Expertise matters – VBT is not yet as common as fusion, so you want a surgical team that has done a good number of these procedures. We have a robust pre-surgery evaluation process, including thorough imaging and input from pulmonologists to check lung function if needed.

Conclusion: Embracing Innovation with Compassion

In conclusion, Vertebral Body Tethering (VBT) offers a promising, less invasive path for treating scoliosis in the right candidates, combining the benefits of spinal correction with the preservation of motion. For many families, it has been a life-changing option – allowing their child to straighten up and thrive without the limitation of a fusion. The excitement among spine specialists about VBT is palpable because it potentially revolutionizes how we treat moderate scoliosis. We are optimistic about the continued positive results we’re seeing. With the right support, children with scoliosis can live their life with greater freedom and confidence.

For a comprehensive evaluation and to explore your treatment options, don’t hesitate to schedule an appointment or seek a second opinion consultation with Dr. Arun Hariharan at Paley Orthopedic & Spine Institute by calling (561) 602-9155.