- Progressive Idiopathic Scoliosis
- Major curve measuring 40-65 degrees
- Vertebral body sizes sufficient to accommodate screws
- At least 10 years old and generally younger than 13
- Sanders Classification 2-5
- Risser 0-3, Triradiates closed
- Child would otherwise require a spinal fusion
Contraindications/Relative Contraindications
- Skeletal Maturity
- Poor bone quality as defined as T-score -1.5 or less
- Previous Spinal Surgery
- Curves >65 degrees
- Kyphosis >50 degrees
- Prior Thoracic Surgery
Complications
There are a number of conditions associated with early onset scoliosis. When taking care of children with these known issues, care should be taken to pay close attention to their spine. The following list includes several conditions known to have early onset spinal deformity. It is by no means complete, and conditions not on the list can still have associated spinal anomalies and progressive deformity.
- Injury to Ureter, Aorta, Vena Cava, Heart, or Lungs
- Uncontrolled bleeding
- Spinal cord injury
- Pneumothorax
- Surgical site infection including chylothorax
- Persistent atelectasis
- Screw pullout or migration
- Tether breakage
- Failure of VBT to modulate spinal growth
- Over-correction of spinal deformity
- Irritation to the diaphragm or psoas
- Back or chest pain
Common Complications
- Tether breakage: This may occur at any time but most commonly occurs between 1.5 - 3 years after surgery. This may result in recurrence of some deformity depending on how much the vertebra have remodeled.
- Failure of Spine Remodeling or Growth Modulation: In patients that do not have significant remaining growth their vertebra may not have the ability to reshape prior to the tether breakage. If the tether breaks, there can be recurrence of the spinal curve.
Less Common Complications
The following complications are much less common, but have been reported and are important for you to understand.
- Injury to nearby structures including the ureters, aorta, vena cava, heart, or lungs
- Bleeding which may require blood transfusion
- Injury to the spinal cord which may result in numbness, weakness or both and may be temporary or permanent
- This can also include a dural tear which is a tear of the outermost membrane of the spinal cord and result in a leak of spinal fluid.
- Pulmonary complications which may include:
- Residual air around the lungs or pneumothorax which may require a chest tube to drain or may resolve on its own
- Residual fluid around the lungs which may require a chest tube to drain or may resolve on its own
- Persistent atelectasis which may cause lower oxygen saturation and a longer hospital stay or in rare cases pneumonia
- Delayed (2-6 weeks) build of fluid around the lung that may require a chest tube
- Surgical Site Infection that may require antibiotics or surgical debridement
- Screw pullout or migration which is where the screw changes position over time. In some cases, this may be observed and may need the screw to be revised
- Over-correction of the spinal deformity can occur in patients with too much growth. In some patients this may be observed, but in some patients this may require release or removal of the tether
- Irritation of the diaphragm or psoas muscles may be temporary or permanent. For those patients where it does not resolve it may require removal of the tether.
- Persistent back or chest pain after surgery. This is most common in patients with preoperative pain, but can occur in any patient. Frequently it will respond to physical therapy but may persist in some patients.
FAQs
What is VBT?
Vertebral Body Tethering is a type of surgical treatment for children with idiopathic scoliosis and sufficient growth remaining as determined by your surgeon. Screws are placed in the vertebral bodies and a poly-ethylene braided rope is placed between the screws and is then tensioned to correct part of the spinal curve. The remaining spinal curve will continue to correct as the child continues to grow. As opposed to a spinal fusion, the child will maintain some motion throughout the instrumented portion of the spine.
How is the procedure performed?
The surgery is typically performed by a spinal surgeon who may or may not work in conjunction with a general surgeon. Neuromonitoring is utilized to monitor spinal cord function throughout the surgery. The surgery is typically performed using a minimally invasive approach either thoracoscopically or through a mini-open incision. This allows for limited blood loss. Screws are then placed in the pre-selected vertebral bodies on the convex side of the curve. Once the screws have been placed, a poly-ethylene braided rope is seated in the screws under tension to partially correct the spinal curve. Typically, a chest tube or drain is then placed at the conclusion of the procedure, which will temporarily remain in the patient.
Should a disc excision (disk removal) be performed during VBT?
At this time, a disc excision is consistent with a spinal fusion. It is believed that by violating the disc you damage it and although in the short term patients may continue to observe relative motion, the discs will ultimately degenerate and auto-fuse over time.
How often should my child follow-up?
Follow-up can vary based upon surgeon preference. Generally, patients are followed every 6-12 months until the child has completed growth. This allows the surgeon to monitor curve correction and also evaluate for complications.
What is recovery like?
Recovery is similar to that of a posterior spinal fusion except for a few differences. Patients typically will have a chest tube or drain after a thoracic VBT that can remain in place for 2-4 days. The hospital stay is between 2-5 days and similar pain medications are used as with a posterior spinal fusion. VBT patients can often begin returning to sports and activities approximately 4-6 weeks after surgery.
Case Studies
Each child's journey with scoliosis is different and will depend on a lot of factors. Things like curve size, previous treatment, flexibility, and growth remaining will impact what your surgeon believes is the best choice of treatment.
The following case examples describe three patients who were treated with vertebral body tethering. A variety of timepoints are included to help you better understand what might be expected should your child undergo this type of surgery and treatment plan.
Case #1
12-year-old female who presented with adolescent idiopathic scoliosis and a flexible curve of 58 degrees bending out to 22 degrees. She did not have any previous treatment and underwent VBT surgery at age 13. Her curve corrected to 34 degrees immediately after surgery and at 5 years post-surgery, she had developed a second curve below the tethered portion of her spine.
Case #2
14-year-old female who presented with adolescent idiopathic scoliosis and a flexible curve of 49 degrees bending out to 13 degrees. She was previously treated with a brace and underwent VBT surgery. Immediately after surgery, her curve corrected to 33 degrees and at her most recent follow-up one year after surgery, her curve corrected to 29 degrees.
Case #3
10-year old female with adolescent idiopathic scoliosis and a flexible curve of 48 degrees bending out to 5 degrees. She was previously treated with a brace and underwent VBT surgery at age 11. Her curve corrected to 25 degrees immediately after surgery. There was curve progression at 2.3 years after the index surgery, her spinal curve over-corrected and she required tether removal 2 months later. At 10 months post-revision surgery, her curve is 35 degrees.
Case #4
12-year-old female who presented with adolescent idiopathic scoliosis and a flexible thoracolumbar curve of 47 degrees, bending out to 18 degrees in the thoracolumbar spine. Immediately after surgery the curve corrected to 11 degrees in the thoracolumbar spine. At >2 year follow-up the curve is <10 degrees.
Case #5
12-year-old female who presented with adolescent idiopathic scoliosis and a flexible double major curve of 50 degrees in the thoracic and 50 degrees in the thoracolumbar spine, bending out to 37 degrees. Immediately after surgery the curve corrected to 15 degrees in the thoracic spine and less than 10 degrees in the thoracolumbar spine. At >2 year follow-up both curves are <10 degrees.
Top 10 Publications/Abstracts
- Anterior vertebral body tethering for idiopathic scoliosis: two-year results. Samdani AF, Ames RJ, Kimball JS, et al. Spine (Phil Pa 1976). 2014 Sep 15;39(20):1688-93.
11 patients with 2 year follow-up after thoracic vertebral body tethering with average of 70% correction of the coronal curve with no major complications.
- Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one year results on the first 32 patients. Samdani AF, Ames RJ, Kimball JS, et al. Eur Spine J. 2015 Jul;24(7):1533-9.
32 patients with 1 year follow-up after thoracic vertebral body tethering with improvement of instrumented and compensatory curves and no major complications.
- Early outcomes of spinal growth tethering for idiopathic scoliosis with a novel device: a prospective study with 2 years of follow-up. Boudissa M, Eid A, Bourgeois E, et al. Childs Nerv Syst (2017) 33:813-818.
Minimum 1 year follow-up of 6 patients that showed improvement of both the instrumented and compensatory curves with no major complications.
- Anterior spinal growth tethering for skeletally immature patients with scoliosis: A retrospective look two to four years post-operatively. Newton PO, Kluck DG, Saito W, et al. J Bone Joint Surg Am. 2018 Oct 3;100(19):1691-1697.
Seventeen patients with 2-4 year follow-up after thoracic vertebral body tethering that showed improvement of instrumented and un-instrumented curves and no change in thoracic kyphosis, but variable outcomes at mid-term follow-up.
- Bonsignore-Opp, L., Murphy, J., Skaggs, D. et al. Pediatric Device Regulation: The Case of Anterior Vertebral Body Tethering. Spine Deform 7, 1019–1020 (2019).
Current Concepts Review on the current state of vertebral body tethering.
- Newton PO, Bartley CE, Bastrom TP, Kluck DG, Saito W, Yaszay B. Anterior Spinal Growth Modulation in Skeletally Immature Patients with Idiopathic Scoliosis: A Comparison with Posterior Spinal Fusion at 2 to 5 Years Postoperatively. J Bone Joint Surg Am. 2020 May 6;102(9):769-777.
Case control study showed higher revision rate for VBT compared to PSF with average 3.4 years follow-up. Final thoracic Cobb, lumbar Cobb, and thoracic rotation all showed greater improvement in the PSF cohort compared to the VBT cohort.
- Surgical Complications of Anterior Vertebral Body Growth Modulation for Skeletally Immature Patients with Idiopathic Scoliosis. Stefan Parent, MD; AbdulmajeedAlzakri, MD; Marjolaine Roy-Beaudry, MSc; Isabelle Turgeon, BS; Marie Beausejour, PhD; Olivier Turcot, MD. POSNA Annual Meeting 2020
Retrospective study of 42 patients that underwent Anterior Vertebral Body Growth Modulation found a re-operation rate of 11% at average 33 months follow-up.
- Shoulder Balance in Lenke Type 1 and 2 Idiopathic Scoliosis following Anterior Vertbral Body Tethering of the Spine. Joshua Murphy, Michael Fields, Hiroko Matsumoto Firoz Miyanji, Stefan Parent, Ron El-Hawary, David Skaggs, Michael G. Vitale, Pediatric Spine Study Group. SRS Annual Meeting 2020.
At mean 2.6 years follow-up after thoracic vertebral body tethering, post-operative shoulder imbalance was reported in 14.8% of patients similar to previous reports after selective posterior spinal fusion.
- Do Patients with Anterior Vertebral Body Growth Modulation have a better Quality of Life than Patients with a Posterior Spinal Fusion? Marjolaine Roy-Beaudry, MSc; Julie Joncas, BSN; Isabelle Turgeon, BS; AbdulmajeedAlzakri, MD; Stefan Parent, MD. IMAST Annual Meeting 2020
At 2 year post-operative follow-up, vertebral body growth modulation patients showed significantly improvement for general health, social functioning, and role emotional using the SF-12 and trend toward better in all domains for the SRS-22.
- Risk of Early Complications Following Anterior Vertebral Body Tethering for Idiopathic Scoliosis. Abdullah Abdullah, Stefan Parent, Firoz Miyanji, Kevin Smit, Joshua Murphy, David Skaggs, Purnendu Gupta, Michael Vitale, Jean Ouellet, Neil Saran, Robert Cho, Ron El-Hawary, Pediatric Spine Study Group. Canadian Orthopaedic Association 2020.
131 patients showed 9.2% re-operation rate with 0.8% rate of unplanned return to the operating room at minimum 1 year of follow-up.