Anterior Vertebral Body Tethering (AVBT) Using Zimmer Biomet Tether System or Dynesys System Components to Treat Pediatric Scoliosis

Study Overview
=================
Brief Summary
-----------------
The Researchers want to assess the short-term safety of Anterior Vertebral Body Tethering (AVBT) in skeletally immature subjects with moderate to severe scoliosis and compare them with a fusion cohort.

Official Title
-----------------
Prospective Pilot Study of Anterior Vertebral Body Tethering Using Zimmer Biomet Tether System or Dynesys System Components to Treat Pediatric Scoliosis

Conditions
-----------------
Scoliosis

Intervention / Treatment
-----------------
* Device: AVBT using Dynesys System Components
* Procedure: Spine fusion


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Male & female, age 10 years to 16 years. Scoliosis curve between 40-70 degrees. At least 1 year of growth remaining measured by Sanders bone age 4 or less or Risser stage 2 or less. Adolescent idiopathic scoliosis. Lenke 1, 2, 3C, 5 (thoracic, thoracolumbar, or thoracic and lumbar). Parents must be able to understand the study and sign the consent document. Assent will be obtained and documented as age appropriate. Patients and parents must be able to comply with study procedures and visits, including 3-month, 1-year, and 2-year follow-up visits. Exclusion Criteria: Congenital, neuromuscular or syndromic scoliosis. Underlying neuromuscular disease. Pregnancy. Nonflexible curves (bending films show residual curve greater than 40 degrees). Prior surgery for scoliosis treatment. Patients with active systemic infection. Known, reported allergies to titanium, PET, or PCU. Known, reported substance abuse, including alcohol.

Ages Eligible for Study
-----------------
Minimum Age: 10 Years
Maximum Age: 16 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Tether group 40 patients and Fusion (control) group 40 patients
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pediatric Scoliosis Patients<br>Tether group | Device: AVBT using Dynesys System Components<br>* Zimmer Biomet Tether System and Dynesys System components are intended to treat scoliosis in skeletally immature children.<br>|
| Active Comparator: Pediatric Scoliosis Control Patients<br>Fusion (control) group | Procedure: Spine fusion<br>* Children with scoliosis undergoing fusion surgery will form the control arm<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Revision spine surgery within 2 years of index procedure | yes/no parameter, was revision surgery performed within 2 years of index procedure | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major cobb angle curve progression greater than 10 degrees and curve magnitude < 50 degrees at latest f/u after 1st erect postop film (Tether arm) | yes/no parameter, did major Cobb angle worsen by 10 degrees and curve magnitude < 50 degrees at latest f/u after 1st erect postop film | 1 year | 
| Curve progression no greater than 10 degrees at latest f/u after 1st erect postop film (Fusion arm) | yes/no parameter, did major Cobb angle worsen by 10 degrees at latest f/u after 1st erect postop film | 1 year | 
| Curve flexibility over instrumented vertebra > 5 degrees | Flexibility films will be obtained in patients postoperatively to assess flexibility | At least 1 year postoperatively | 
| Spinal disc health utilizing MRI | Spinal disc health will be assessed in Tether patients post-operatively using an MRI in conjunction with the Pfirrmann classification (scored I to V, where I indicated normal and V indicated the worst degeneration). | At least 1 year postoperatively |