Interventional procedure overview of vertebral body tethering for idiopathic scoliosis in children and young people

Ames RJ, Samdani A and Betz RR (2016) Anterior scoliosis correction in immature patients with idiopathic scoliosis. Operative Techniques in Orthopaedics 26(4): 247-57

Review

Anterior VBS and VBT have been shown to be useful in treating skeletally immature patients with idiopathic scoliosis. However, long-term follow up is lacking.

Review article

Aronsson DD and Stokes IAF (2011) Nonfusion treatment of adolescent idiopathic scoliosis by growth modulation and remodeling. Journal of pediatric orthopedics 31(1suppl): 99-106

Review

A brace that applies the appropriate loading and is worn as prescribed may dramatically improve the results of brace treatment. A procedure using external fixation or adjustable anterolateral tethering may achieve a nonfusion correction of AIS.

Review article

Baker CE, Kiebzak GM and Neal KM (2021) Anterior vertebral body tethering shows mixed results at 2-year follow-up. Spine Deformity 9(2): 481-9

Case series

n=17

Despite several final curves >35°, 4 revisions, and 9 broken tethers, most patients (53%) were considered successful. Lumbar ABVTs correct more intraoperatively and faster postoperatively. Patients who are tethered during or slightly after the curve acceleration phase of growth may have more successful outcomes than patients tethered prior to the curve acceleration phase. AVBT requires further study with longer outcomes to define best practices for indications, level selections, and surgical techniques

Small sample

Baker CE, Milbrandt TA and Larson AN (2021) Anterior vertebral body tethering for adolescent idiopathic scoliosis: early results and future directions. The Orthopedic clinics of North America 52(2): 137-47

Review

AVBT is a growing technique targeted for patients who are skeletally immature and desire to maintain spinal motion. It has shown early success to correct scoliosis and avoid fusion surgery, which is a major advancement in the care of AIS; however, it has shown a higher reoperation rate than PSF and long-term outcomes are yet to be defined, making appropriate patient counselling of utmost importance. The ideal surgical candidate and timing of intervention are still being determined. Patients who are motivated to maintain spinal motion can benefit from this technique.

Review article

Baroncini A, Kobbe P, Tingart M et al. (2021) Return to sport and daily life activities after vertebral body tethering for AIS: analysis of the sport activity questionnaire. European Spine Journal 30(7): 1998-2006

Case series

n=31

VBT allows patients to quickly return to their preoperative activity level, irrespectively of the postoperative Cobb angle or type of instrumentation.

Small sample, analysis of the sport activity questionnaire

Baroncini A, Trobisch PD, Rodriguez L et al. (2021) Feasibility of single-staged bilateral anterior scoliosis correction in growing patients. Global Spine Journal 11(1): 76-80

Case series

n=25

Data suggests that bilateral, single-stage surgery for dynamic scoliosis correction (VBT) is feasible albeit with an elevated complication rate that may partially attributable to the learning curve. Future research should focus on the cause of pulmonary complications and include a matched comparative analysis with traditional posterior fusion.

It was unclear how many patients had idiopathic scoliosis.

Baroncini A, Trobisch PD, Birkenmaier C et al. (2021) Radiographic results after vertebral body tethering. Zeitschrift fur Orthopadie und Unfallchirurgie

Systematic review

n=175 (9 studies)

The mean correction on the coronal plane was 52%, and there was no significant change in sagittal parameters. The revision rate was 18.9%. The methodological quality assessment with the Coleman score gave unsatisfactory results, so that available data are not sufficient to propose general indications or guidelines to perform VBT.

Outcomes for idiopathic scoliosis were not reported separately.

Betz RR, Antonacci MD and Cuddihy LA (2018) Alternatives to spinal fusion surgery in pediatric deformity. Current Orthopaedic Practice 29(5): 430-5

Review

Fusionless surgery procedures may not have long-term data available today, but they may currently be acceptable for patients/parents who place a premium on motion and understand that long-term data are not available. Importantly, unlike fusion, these fusionless procedures do not burn any bridges and allow for any improvements in technology in the future.

Review article

Boudissa M, Eid A, Bourgeois E et al. (2017) Early outcomes of spinal growth tethering for idiopathic scoliosis with a novel device: a prospective study with 2 years of follow up. Child's nervous system: ChNS: official journal of the International Society for Pediatric Neurosurgery 33(5): 813-8

Case series

n=6

The procedure allowed a stabilisation of the deformity during growth spurt. Validated devices and further studies with longer term follow up are needed to confirm the efficiency of this technique. This small cohort of patients is a source of reflection for further medical devices developments.

Small sample

Braun JT (2014) Comparison of two fusionless scoliosis surgery methods in the treatment of progressive adolescent idiopathic scoliosis: a preliminary study. Darthmouth Orthop J

Non-randomised comparative study

n=9 (VBT, n=5; vertebral body stapling, n=4)

Both initial correction and subsequent control of curve progression are important in the fusionless treatment of AIS. In this preliminary study, it appears that ligament tethering provides greater initial correction and subsequent control of AIS curve progression than vertebral stapling

Small sample

Buyuk AF, Milbrandt TA, Mathew SE et al. (2021) Measurable thoracic motion remains at 1 year following anterior vertebral body tethering, with sagittal motion greater than Coronal Motion. The Journal of bone and joint surgery. American volume

Case series

n=32

At 1 year following thoracic anterior VBT for the treatment of AIS, the thoracic spine showed a measurable range of coronal and sagittal plane motion over the instrumented levels without evidence of complete autofusion. Motion in the coronal plane decreased by 77% following anterior vertebral body tethering. These findings provide proof of concept that sagittal spinal motion is preserved after thoracic anterior VBT, although the functional importance remains to be determined.

Small sample

Buyuk AF, Milbrandt TA, Mathew SE et al. (2021) Does preoperative and intraoperative imaging for anterior vertebral body tethering predict postoperative correction? Spine Deformity 9:743-50

Case series

n=51

Preoperative bending radiographs provide a reasonable estimate of postoperative correction for patients undergoing anterior VBT with tensioning of the cord. Surgeons should expect the major Cobb angle to increase on first erect radiographs compared to intraoperative radiographs. These findings may guide patient selection and assist surgeons in achieving appropriate correction intraoperatively.

Shot-term follow up (only postoperative data reported)

Chen E, Sites Brian DR, Lisa A et al. (2019) Characterizing anesthetic management and perioperative outcomes associated with a novel, fusionless scoliosis surgery in adolescents. AANA journal 87(5): 404-10

Non-randomised comparative study

n=75 (anterior VBT, n=35; PSF, n=40)

This study suggested that patients having anterior VBT with neuraxial analgesia need less opioid administration than patients having PSF and may be discharged sooner. Although limited by several differences between the cohorts, the findings can inform both spine surgeons and their patients about the expected recovery profile and the likely decreased postoperative opioid requirement associated with anterior VBT and serve as a baseline for future adjustments to perioperative care.

Limited, short-term efficacy data were reported.

Cheung ZB, Selverian S, Cho B H et al. (2019) Idiopathic scoliosis in children and adolescents: emerging techniques in surgical treatment. World neurosurgery 130: e737-42

Review

Recent developments in fusionless and growth modulating techniques, including VBS, VBT, magnetically controlled growing rods, ApiFix, and sublaminar polyester bands, have attempted to address concerns about the performance of early fusion in young patients with AIS. Although these new emerging techniques have demonstrated promising results, larger prospective studies are still needed to better evaluate their safety and long-term efficacy in the treatment of AIS.

Review article

Cobetto N, Aubin CE and Parent S (2020) Anterior vertebral body growth modulation: assessment of the 2-year predictive capability of a patient-specific finite-element planning tool and of the growth modulation biomechanics. Spine 45(18): e1203-e1209

Case series

n=45

This study demonstrates the finite element model clinical usefulness to rationalise surgical planning by providing clinically relevant correction predictions. The AVBGM biomechanical effect on growth modulation over time seemed to be maximised during the first year following the installation.

Numerical planning and simulation

Cobetto N, Aubin CE and Parent S (2018) Contribution of lateral decubitus positioning and cable tensioning on immediate correction in anterior vertebral body growth modulation. Spine deformity 6(5): 507-13

Case series

n=20

The majority of curve correction was achieved by lateral decubitus positioning. The main role of the cable was to apply supplemental periapical correction and secure the intraoperative positioning correction. Increases in cable tensioning furthermore rebalanced initially asymmetric compressive stresses. This study could help improve the design of AVBGM by understanding the contributions of the surgical procedure components to the overall correction achieved.

Computational simulation

Cobetto N, Aubin CE and Parent S (2018) Surgical planning and follow up of anterior vertebral body growth modulation in pediatric idiopathic scoliosis using a patient-specific finite element model integrating growth modulation. Spine deformity 6(4): 344-50

Case series

n=20

A numeric model simulating immediate and post-two-year effects of anterior vertebral body growth modulation enabled to assess different implant configurations to support surgical planning.

Numerical planning and simulation, with small sample

Cobetto N, Aubin CE and Parent S (2020) Anterior vertebral body growth modulation: assessment of the 2-year predictive capability of a patient-specific finite-element planning tool and of the growth modulation biomechanics. Spine 45(18): e1203-e1209

Case series

n=45

This study demonstrates the FEM clinical usefulness to rationalize surgical planning by providing clinically relevant correction predictions. The AVBGM biomechanical effect on growth modulation over time seemed to be maximised during the first year following the installation.

Numerical planning and simulation

Cobetto N, Parent S and Aubin CE (2018) 3D correction over 2years with anterior vertebral body growth modulation: A finite element analysis of screw positioning, cable tensioning and postoperative functional activities. Clinical biomechanics (Bristol, Avon) 51: 26-33

Case series

n=10

This study showed the biomechanical possibility to adjust the fusionless instrumentation parameters to improve correction in frontal and sagittal planes, but not in the transverse plane. The convex side stresses increase in the supine position may suggest that growth modulation could be accentuated during night-time.

Small sample, biomechanical study with limited efficacy outcomes.

Courvoisier A, Eid A, Bourgeois E et al. (2015) Growth tethering devices for idiopathic scoliosis. Expert review of medical devices 12(4): 449-56

Review

Flexible tethers are promising new tools for patients with severe curves and significant remaining growth. The prerequisite for progressive correction is the flexibility of the curve (and consequently a significant correction of the curve) and ideally an open triradiate cartilage. A big issue is the amount of tension required in the tether to reach the desired correction.

Review article

Crawford CH and Lenke LG (2010) Growth modulation by means of anterior tethering resulting in progressive correction of juvenile idiopathic scoliosis: a case report. The Journal of bone and joint surgery. American volume 92(1): 202-9

Case report

n=1

The present report demonstrates the intermediate term safety and efficacy of a novel procedure in a single patient. Careful ongoing assessment of the patient and others is needed to determine if this procedure will become accepted for the treatment of spinal deformities in the growing child.

Single case report

Hoernschemeyer DG, Boeyer ME, Robertson ME et al. (2020) Anterior vertebral body tethering for adolescent scoliosis with growth remaining: a retrospective review of 2 to 5-year postoperative results. The Journal of bone and joint surgery. American volume 102(13): 1169-1176

Case series

n=27

This study shows the success and revision rates as well as the impact of a suspected broken tether on the procedural success of VBT. Despite the patient population being slightly more mature at the time of the surgical procedure compared with previous studies, there was a higher success rate and a lower revision rate. A PSF was avoided in 93% of patients, indicating that VBT may be a reliable treatment option for adolescent scoliosis in skeletally immature individuals.

Small sample

Jain V, Lykissas M, Trobisch P et al. (2014) Surgical aspects of spinal growth modulation in scoliosis correction. Instructional course lectures 63: 335-44

Review

The early results for spinal growth modulation are promising and continued clinical studies are needed.

Review article

Mathew S, Larson AN, Milbrandt TA et al. (2021) Defining the learning curve in CT-guided navigated thoracoscopic vertebral body tethering. Spine Deformity

Case series

n=67

This series has demonstrated improvements in surgical efficiency for VBT including reduced EBL, operative time, anaesthesia time and hospital stay over a 5-year period. This indicates improved surgical technique and outlines the significant learning curve for surgeons who wish to perform this procedure. Improved surgeon training programs and newer instrumentation may reduce this learning curve.

This study reviewed the learning curve of the navigated VBT technique, with 3-month follow-up outcomes.

Milbrandt TA, Mathew SE, Larson AN et al. (2021) Does preoperative and intraoperative imaging for anterior vertebral body tethering predict postoperative correction? Spine Deformity 9(3): 743-50

Case series

n=51

Preoperative bending radiographs provide a reasonable estimate of postoperative correction for patients undergoing AVBT with tensioning of the cord. Surgeons should expect the major Cobb angle to increase on first erect radiographs compared to intraoperative radiographs. These findings may guide patient selection and assist surgeons in achieving appropriate correction intraoperatively.

Outcomes were measured at first erect imaging.

Miyanji F, Pawelek J, Nasto L A et al. (2020) Safety and efficacy of anterior vertebral body tethering in the treatment of idiopathic scoliosis. The bone & joint journal 102b (12): 1703-8

Case series

n=57

Anterior VBT is associated with satisfactory correction of deformity and an acceptable complication rate when used in skeletally immature patients with idiopathic scoliosis. Improved patient selection and better implant technology may improve the 15.8% rate of revision surgery in these patients. Further scrutiny of the true effectiveness and long-term risks of

this technique remains critical.

Small sample

Newton PO (2020) Spinal growth tethering: Indications and limits. Annals of Translational Medicine 8(2): 159

Review

Initial results of anterolateral tethering in growing patients with spinal deformities are encouraging, however the results 3 to 4 years after the procedure are somewhat mixed. Further research is ongoing and many remain optimistic that improvements in technology and understanding will continue to lead to better patient outcomes.

review article

Newton PO, Kluck DG, Saito W et al. (2018) Anterior spinal growth tethering for skeletally immature patients with scoliosis: a retrospective look two to four years postoperatively. The Journal of bone and joint surgery. American volume 100(19): 1691-7

Case series

n=17 (idiopathic scoliosis, n=14; syndromic scoliosis, n=3)

The results demonstrated that at mid-term follow-up, ASGT showed a powerful, but variable, ability to modulate spinal growth and did so with little perioperative and early postoperative risk. Fusion was avoided for 13 of the 17 patients. The overall success rate was 59%, with a 41% revision rate. Understanding the parameters leading to success or failure will be critical in advancing a reliable definitive nonfusion treatment for progressive scoliosis in the future.

Small sample and outcomes for idiopathic scoliosis not reported separately

Parent S and Shen J (2020) Anterior vertebral body growth-modulation tethering in idiopathic scoliosis: surgical technique. The Journal of the American Academy of Orthopaedic Surgeons 28(17): 693-699

Review

Fusionless treatment options, such as anterior vertebral body growth modulation, have been developed to treat these patients while avoiding the complications of posterior rigid fusion. Good results have been shown in recent literature with proper indications and planning in the skeletally immature patient.

Review article

Pehlivanoglu T, Oltulu I, Erdag Y et al. (2021) Double-sided vertebral body tethering of double adolescent idiopathic scoliosis curves: radiographic outcomes of the first 13 patients with 2 years of follow-up. European Spine Journal 30: 1896-904

Case series

n=13

Double-sided VBT was detected to provide 80% of thoracic (48.2° to 9.7°) and 82% of thoracolumbar-lumbar curve correction (45.3° to 8.2°) as a result of average 2 years. As being a growth modulating treatment option, double-sided VBT as applied under strict inclusion criteria was shown to be safe and effective for the correction of double curves in skeletally immature patients with AIS, by yielding a gradual, growth-assisted correction of both curves together with the preservation of coronal-sagittal balance without any major complications.

Small sample

Pehlivanoglu T, Oltulu I, Ofluoglu E et al. (2020) Thoracoscopic vertebral body tethering for adolescent idiopathic scoliosis: a minimum of 2 years' results of 21 patients. Journal of pediatric orthopedics 40(10): 575-80

Case series

n=21

Anterior VBT as a growth modulating treatment option by allowing the correction of the scoliotic deformity and preserving coronal balance was detected to be a safe and effective option for the surgical treatment of AIS in skeletally immature patients, if applied under strict inclusion criteria. VBT by allowing preservation of spinal segmental motion is yielding promising radiographic results without causing any major complications.

Small sample

Oltulu I, Erdag Y, Korkmaz E et al. (2021) Double-sided vertebral body tethering of double adolescent idiopathic scoliosis curves: radiographic outcomes of the first 13 patients with 2 years of follow-up. European Spine Journal 30(7): 1896-904

Case series

n=13

Double-sided VBT was detected to provide 80% of thoracic (48.2° to 9.7°) and 82% of thoracolumbar-lumbar curve correction (45.3° to 8.2°) as a result of average 2 years. As being a growth modulating treatment option, double-sided VBT as applied under strict inclusion criteria was shown to be safe and effective for the correction of double curves in skeletally immature patients with AIS, by yielding a gradual, growth-assisted correction of both curves together with the preservation of coronal-sagittal balance without any major complications.

Small sample

Samdani AF, Ames RJ, Kimball JS et al. (2015) Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one-year results on the first 32 patients. European spine journal: official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 24(7): 1533-9

Case series

n=32

The results indicate that anterior VBT is a safe and potentially effective treatment option for skeletally immature patients with idiopathic scoliosis. These patients experienced an improvement of their scoliosis with minimal major complications. However, longer-term follow up of this cohort will reveal the true benefits of this promising technique.

Small sample with 1-year follow-up outcomes

Samdani AF and Betz RR. (2015) Growth modulation techniques for adolescent idiopathic scoliosis. Seminars in Spine Surgery 27(1): 52-7

Review

Growth modulation techniques, such as vertebral body stapling and vertebral body tethering, offer a fusionless option, which harnesses a patient's remaining growth to progressively correct the curve. These techniques offer a promising

alternative to appropriately selected skeletally immature patients with idiopathic scoliosis.

Review article

Samdani AF, Ames RJ, Kimball JS et al. (2014) Anterior vertebral body tethering for idiopathic scoliosis: two-year results. Spine 39(20): 1688-93

Case series

n=11

Anterior VBT is a promising technique for skeletally immature patients with idiopathic scoliosis. This technique can be performed safely and can result in progressive correction.

Small sample

Senkoylu A, Riise RB, Acaroglu E et al. (2020) Diverse approaches to scoliosis in young children. EFORT Open Reviews 5(10): 553-62

Review

Anterior VBT seems to be a promising novel technique for the treatment of idiopathic scoliosis in immature cases. It provides substantial correction and continuous curve control while maintaining mobility

between spinal segments. However, long-term results, adverse effects and their prevention should be clarified by future studies.

Review article

Shen J and Parent S (2021) Iatrogenic dural tear after growth modulation in AIS: an unusual complication and its management. Spine deformity

Case report

n=1

Iatrogenic CSF leak in AVBGM remains a rare complication. This is the first report of such a case that involves a Chiari-like deformity on initial MRI investigation. We suggest that an MRI is performed for all patients presenting with symptoms of CSF leak after AVBGM.

Single case report

Skaggs DL, Akbarnia BA, Flynn JM et al. (2014) A classification of growth friendly spine implants. Journal of pediatric orthopedics 34(3): 260-74

Review

Growth friendly spinal implant systems fall into 3 categories based on the forces of correction the implants exert on the spine: distraction based, compression based and guided growth. Each type of system has potential benefits and shortcomings.

Review article

Szapary, Hannah J., Greene, Nattaly, Paschos, Nikolaos K. et al. (2021) A Thoracoscopic Technique Used in Anterior Vertebral Tethering for Adolescent Idiopathic Scoliosis. Arthroscopy Techniques 10(3): e887-e895

Review

Although more studies will be needed to further characterise the outcomes and complications of anterior VBT, this thoracoscopic approach is a reproducible and effective treatment that takes advantage of continued spinal growth in paediatric patients with adolescent idiopathic scoliosis, who would otherwise require spinal arthrodesis.

Review article

Takahashi Y, Saito W, Yaszay B et al. (2021) Rate of scoliosis correction after anterior spinal growth tethering for idiopathic scoliosis. The Journal of bone and joint surgery. American volume

Case series

n=23

Scoliosis correction was associated with overall height changes and occurred primarily within 2 to 3 years after surgery in this cohort of largely Risser stage 0 patients. The correction rate was 2.8^o per segment per year for the first 2 years in the Sanders stage 2 group, compared with 1.2^o per segment per year for the Sanders stage 3 group. Surgical timing that considers the patient's skeletal maturity is an important factor in generating proper postoperative correction after anterior spinal growth tethering.

Small sample

Yucekul A, Yilgor C, Alanay A et al. (2021) Does vertebral body tethering cause disc and facet joint degeneration? A preliminary MRI study with minimum 2-years follow-up. Spine Journal

Case series

n=35

Intermediate discs and facet joints were preserved after growth modulation with VBT surgery at a mean follow-up of 29 months. Studies in larger cohorts with longer follow-up are warranted to have more in-depth analyses of the effects of relative stabilisation and altered biomechanical loads.

Small sample with 2-year follow-up data