Clinical trial NCT04505579: The Tether™ - Vertebral Body Tethering System Post Approval Study
Official title: The Tether™ - Vertebral Body Tethering System Post Approval Study
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Scoliosis Idiopathic
Lead sponsor: ZimVie
Sponsor class: INDUSTRY
Collaborators: name: Setting Scoliosis Straight Foundation
name: Exponent, Inc.
First posted: 2020-08-10
Enrollment: 200
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: The Tether™ - Vertebral Body Tethering System is indicated for skeletally immature patients that require surgical treatment to obtain and maintain correction of progressive idiopathic scoliosis, with a major Cobb angle of 30 to 65 degrees whose osseous structure is dimensionally adequate to accommodate screw fixation, as determined by radiographic imaging. Patients should have failed bracing and/or be intolerant to brace wear.

Brief summary: This study is an opportunity to provide continued reasonable assurance of the safety and probable benefit of The Tether HUD. The study will collect long term safety and efficacy information from patients who have had their idiopathic scoliosis treated via anterior vertebral body tethering (AVBT) with The Tether.

Detailed description: While spinal fusion remains the standard surgical treatment for progressive idiopathic scoliosis, concerns about the long-term effects of spinal fusion have led to the investigation of growth-modulation techniques. Anterior Vertebral Body Tethering (AVBT) is one such technique that utilizes growth modulation to remodel the shape of the vertebra and straighten scoliotic curves in skeletally immature individuals. In this technique, screws are inserted at each vertebral level for the length of the convex side of the curve. A strong cord is connected through the screw tulip heads and used to initially straighten the curve as each level is fixed with a set screw. Following surgery and during the growth period the spine begins to remodel according to the Hueter-Volkmann Law, bone growth is relatively inhibited in areas of increased pressure (convex or tethered side) and relatively stimulated in areas of decreased pressure or tension (concave side). Following this principle, AVBT has been shown to alter spinal growth with the potential to correct scoliosis while maintaining spine flexibility.

The objective of the study is to assess the ongoing safety and probable benefit of The Tether HUD which was approved by the FDA under an HDE. Subject enrollment and data collection will be managed by the Harms Study Group (HSG) and Setting Scoliosis Straight Foundation (SSSF) Registry. Institutions that are HSG members or affiliates, with Investigators/surgeons that are trained and approved to perform surgeries with The Tether, will participate in the registry. Ten sites from this group will be identified as study sites specific to this Tether post-approval study (PAS). Consecutive subjects from these sites, that meet the eligibility criteria of this study, will be flagged in the registry as the PAS cohort and the study endpoints will be assessed across this population.

Eligibility criteria: Inclusion Criteria:

* Diagnosis of progressive idiopathic scoliosis
* Skeletally immature, based on both Risser (\<5) and Sanders (\<8) assessments
* Major Cobb angle ≥30° and ≤65°
* Osseous structure dimensionally adequate to accommodate screw fixation, as determined by radiographic imaging
* Failed or intolerant to bracing

Exclusion Criteria:

* Presence of any systemic infection, local infection, or skin compromise at the surgical site
* Prior spinal surgery at the level(s) to be treated
* Documented poor bone quality, defined as a T-score -1.5 or less
* Any other medical or surgical condition which would preclude the potential benefit of spinal surgery, such as coagulation disorders, allergies to the implant materials, and patient's unwillingness or inability to cooperate with post-operative care instructions
* Unwillingness, inability, or living situation (e.g. custody arrangements, homelessness, detention) that would preclude ability to return to the study site for follow-up visits as described in protocol and Informed Consent
* Unwillingness to sign Informed Consent Form and participate in study procedures

Primary outcomes:
measure: Rate of SAEs and device- &/or procedure-related AEs
timeFrame: AVBT surgery to five year post-op
measure: Percentage of subjects with maintenance of the major Cobb angle less than or equal to 40 degrees at 60 months post-surgery
timeFrame: AVBT surgery to five year post-op
Secondary outcomes:
measure: Adverse Events
timeFrame: AVBT surgery to five year post-op
measure: Reoperation
timeFrame: AVBT surgery to five year post-op
measure: Number of participants with new curves that develop above or below the tethered portion of the spine.
timeFrame: AVBT surgery to five year post-op
measure: Number of participants with secondary curves that progress to the point of clinical significance.
timeFrame: AVBT surgery to five year post-op
measure: Number of participants with device integrity failures including cord breakage and screw migration.
timeFrame: AVBT surgery to five year post-op
measure: Mean (SD) and distributions of sagittal balance (mm) from pre-op through last visit
timeFrame: Baseline to five year post-op
measure: Mean (SD) and distributions of lumbar lordosis (degrees) from pre-op through last visit.
timeFrame: Baseline to five year post-op
measure: Mean score of Scoliosis Research Society 22r Patient Questionnaire
timeFrame: Baseline to five year post-op
measure: Number of participants with compromised lung function
timeFrame: Baseline to five year post-op
measure: Measurement (degrees rotation) of trunk shape by scoliometer device. Mean (SD) [min, max] will be reported.
timeFrame: Baseline to five year post-op
measure: Trunk flexibility as determined by distance (cm) of flexion and lateral bend using fingertip to floor method.
timeFrame: Baseline to five year post-op
Other outcomes:
Locations:
city: San Diego
country: United States
facility: Rady Children's Hospital
state: California
city: Aurora
country: United States
facility: Children's Hospital Colorado
state: Colorado
city: Jacksonville
country: United States
facility: Nemours Children's Health
state: Florida
city: Atlanta
country: United States
facility: Children's Healthcare of Atlanta
state: Georgia
city: New Orleans
country: United States
facility: Ochsner Health
state: Louisiana
city: Rochester
country: United States
facility: Mayo Clinic
state: Minnesota
city: Columbia
country: United States
facility: University of Missouri - Columbia
state: Missouri
city: New York
country: United States
facility: Mount Sinai
state: New York
city: Philadelphia
country: United States
facility: Shriners Children's Hopital
state: Pennsylvania
city: Seattle
country: United States
facility: Seattle Children's
state: Washington
Study officials:
References: