Your Comprehensive Guide to Vertebral Body Tethering (VBT)

Has your child recently been diagnosed with scoliosis? If so, then you’re probably wondering what comes next.

For many children with scoliosis, treatment often means relying on the assistance of a rigid brace. Although braces can stop the progression of abnormal curvature, they can’t, however, reverse the existing problem.

As a result, those with severe scoliosis may require surgery. In the past, doctors accomplished this through spinal fusion surgery. This process often involved inserting rods into the spine to achieve realignment and then using a bone graft to fuse together adjacent segments of the spine. These procedures were (and often still are) complicated, requiring longer recovery times and running the risk of potential complications.

Vertebral Body Tethering: A Less Invasive Alternative

In contrast, vertebral body tethering (VBT) is a newer, less invasive means of treating scoliosis. It allows for scoliosis management as adolescents experience growth spurts AND works to reverse curvature simultaneously.

VBT, as the name suggests, relies on a tethering system to realign your child’s spinal curvature as the spine matures in real-time. As such, meticulous placement of the device is key to achieving successful and long-lasting results.

In order to work properly, therefore, VBT requires implementation by a highly skilled surgeon. The ideal person for the job will have acquired advanced knowledge of spinal physiology and have clocked countless hours of experience with installing the device.

For truly advanced spine care solutions, look no further than to Dr. Jason Lowenstein of The Advanced Spine Center. As Director of the Scoliosis and Spinal Deformity Department at Morristown Medical Center, Dr. Lowenstein serves as a regional referral source for complex spinal deformity cases, including those that qualify for VBT.

Additionally, throughout the course of his 15-year career, Dr. Lowenstein has routinely been recognized as a “Top Orthopedic Spine Surgeon” for adolescents by New Jersey Monthly Magazine, Inside Jersey Magazine, New Jersey Family Magazine, Castle Connolly,and With an outstanding 4.9-star ranking on Google My Business, his patients certainly agree: If your child requires scoliosis treatment, then The Advanced Spine Center is the place to go.

What is Scoliosis?

Despite being told countless times to “sit up straighter,” your spine actually consists of normal, healthy curves. In fact, when viewing the spine from the side, you should notice inward curves near the neck and lower back (known as lordosis). Near the chest, another curve arcs toward the back of your body (known as kyphosis).

These curves in the spine are important for posture, balance, and standing upright.

However, you view your spine from the back, it should appear more like a straight line. Abnormal curves to the left or right (when viewed from the back) are known as scoliosis.

Common Types of Scoliosis

  • Idiopathic Scoliosis: The most common type of scoliosis; accounting for up to 80% of all cases. Idiopathic scoliosis often develops in childhood or adolescence. The exact cause of idiopathic scoliosis isn’t known.
  • Degenerative Scoliosis: This adult form of scoliosis occurs when the bones and joints in the spine degenerate, creating unhealthy curvature.
  • Neuromuscular Scoliosis: A form of scoliosis occurring in those with conditions like cerebral palsy or muscular dystrophy. Complications of these conditions can lead to spinal deformity.
  • Congenital Scoliosis: While rare, an abnormal curvature can develop in a maturing fetus. This is often a serious condition that requires surgery.

Most types of scoliosis involve structural changes to the spine. The spine begins to rotate as it curves, altering the structure. This rotation also affects nearby tissues like muscles, tendons, and ligaments. As the spinal deformity continues to progress, it can lead to painful symptoms, difficulty walking, and decreased range of motion.

Children and adolescents dealing with scoliosis may also suffer from self-esteem issues. During the formative years, children want to fit in with their peers. A spinal deformity can cause them to stand out, become ostracized, or even bullied. As such, it’s important to address both the physical and emotional aspects of scoliosis for children.

Treating Scoliosis in Children & Adolescents

Luckily, many children diagnosed with idiopathic scoliosis have mild cases. About 90% of idiopathic cases only require observation. Usually, your child will see a doctor every 4 to 6 months for several years. A routine physical exam and X-rays will allow the doctor to see if the curve is becoming worse.

Most commonly, physicians measure scoliosis using the Cobb angle. Doctors rely on a specific formula to determine the Cobb angle when viewing x-rays of the spine. For example, any Cobb angle over 10 degrees warrants a scoliosis diagnosis.

If a child’s scoliosis curve progresses at least 5 degrees between observations, bracing may be necessary. Also, a brace is used if the Cobb angle progresses beyond 25 degrees while significant growth still remains.

In addition, there are several types of braces your doctor may recommend. Your doctor will ask your child to wear certain braces overnight. Your child will wear other models up to 23 hours a day. Braces do not correct scoliosis, however, as mentioned. Nevertheless, when used properly, they prevent scoliosis from becoming worse.

If scoliosis continues to worsen despite bracing, then surgery may be the next option. Surgery stops the curve’s progression, reduces the deformity, and maintains the spine’s natural curves.

Surgery is generally recommended for those who are still growing and who have a Cobb angle between 30-65 degrees.

Advances in Scoliosis Treatment

As mentioned earlier, spinal fusion surgery and/or anchoring rods were common practice in the past. Unfortunately, these are relatively invasive surgeries that could be difficult for children or adolescents to tolerate. Also,  the inherent nature of these surgeries often results in decreased spinal mobility.

More recently, vertebral body tethering has replaced spinal fusion surgery as an option for some children and adolescents. There are some definite benefits of VBT over traditional methods. You should discuss these with a qualified surgeon who routinely practices VBT.

What is Vertebral Body Tethering (VBT)?

Spinal fusion uses bone grafts to fuse vertebrae together to form a solid bone that no longer moves. Prior to spinal fusion surgery, your doctor anchors rods into the spine. Your doctor will need to replace these every 6 to 12 months until your child’s skeleton fully matures.

Vertebral body tethering is different, however.

Rather than using bone grafts or stiff rods, vertebral body tethering uses a strong flexible cord to pull on the outside of a scoliosis curve, thus straightening the spine.

VBT uses a child’s own growth process to straighten the spine—a process known as growth modulation. When the vertebrae are pulled by the cord, it applies pressure on the outside of the curve. This slows the growth of the outside of the vertebrae so that the other side has a chance to “catch up.”

There are four components that make vertebral body tethering work:

  • Cord: A cord made of a special polymer, used to realign the spine.
  • Bone screws: Surgical screws inserted into the vertebrae to secure the cord and let the surgeon pull on the affected vertebra.
  • Set screws: Small screws placed at the top of the bone screws to maintain the cord’s tension.
  • Anchors: Circular titanium alloy implants placed against the vertebrae to support the bone screws

Your surgeon will perform VBT under general anesthesia. The surgeon makes 3 to 4 small incisions along the patient’s side. Then, using specially designed tools, the surgeon inserts the anchors and screws into the affected vertebrae.

Once your doctor inserts the screws, he/she runs a cord through the incision and places it into the U-shaped head of the bone screws. He or she then tightens the cord by placing an additional set of screws on top of the bone screws.

When to Use Vertebral Body Tethering (VBT)

With all that said, VBT is not for everyone. Like some other scoliosis treatments, VBT is best suited for children or adolescents with progressive idiopathic scoliosis. Furthermore, the Cobb angle in question needs to be between 30 and 65 degrees. Also, the bone structure and thickness of the vertebrae must be appropriate for inserting bone screws.

And, of course, VBT only works for those adolescents who are still growing. Likewise, the spine must have a degree of curve flexibility, as assessed by your orthopedic surgeon. VBT relies on an individual’s growth to straighten the spine. As such, VBT unfortunately will not work for those who are already skeletally mature.

Benefits of Vertebral Body Tethering (VBT)

In general, vertebral body tethering is less invasive than spinal fusion surgery. VBT uses smaller incisions that can reduce blood loss, scarring, and infection. Also, VBT uses less surgical hardware.

Children and adolescents don’t have to wait until they are skeletally mature to undergo VBT. In contrast, for a spinal fusion, younger patients need to rely on growing rods inserted regularly until they have fully grown.

One key benefit of VBT is that it allows for the retention of spinal mobility. Spinal fusion, for example, bonds vertebrae together as one solid bone. This creates a significant decrease in spinal motion. This reduction in mobility may make it harder for your child to engage in the things he or she loves, even as an adult.

Risks of Vertebral Body Tethering (VBT)

Every surgery has risks. Like many surgeries, VBT can cause wound infections, anesthesia complications, or nerve damage.

VBT poses the risk of deformity overcorrection, inadequate curve correction, or loss of curve correction. Also, VBT is a relatively new scoliosis treatment. The long-term effects are not as well known as spinal fusion surgery.

You always should discuss the risks versus benefits with your doctor before making any surgical decisions.

Is Vertebral Body Tethering (VBT) Right for Your Child?

Treating scoliosis is a highly individualized process. Finding the right treatment depends on the severity of scoliosis, the accompanying symptoms, and how much growing your child still needs to do.

Dr. Jason Lowenstein and his team are experts in the field of scoliosis and spinal deformities. If you are looking for an award-winning doctor who combines compassion with the latest evidence-based treatments, call (855) 220-5966 for a consultation.

Discover why Dr. Jason Lowenstein has been annually recognized as a “Favorite Kids Doc” and “Family Favorite” by New Jersey Family Magazine since 2015.