The goal of this observational study is to collect information about The Tether™ device in participants with progressive idiopathic scoliosis, Lenke Type 1 curves. The main purpose is to provide assessment of:

• ongoing safety
• probable benefits Participants who will receive The Tether™ during spine surgery will have to attend follow-up visits which are part of standard-of-care.

This study is designed to be prospective. After the initial visit, followed by the surgery, the participant is expected to take part in the study for a time period of 5 years post-surgery.

Patients will be enrolled during a period of 36 months, and the study will last until complete collection of the 5-year follow-up data. Data will be collected at: first follow-up post discharge, 6, 12, 24, 36, 48 and 60 months.

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 bracing and/or be intolerant to brace wear;
• Lenke Type 1 curves (i.e., main thoracic);
• Signed Informed Consent Form by legal guardian or by the patient if ≥ 16 years old.
• The decision to treat patients with The Tether™ - VBT System was made by the patient's clinician outside of this research

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;
• Known poor bone quality defined as a T-score -1.5 or less;
• Skeletal maturity;
• 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 patients 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;
• Patients who are pregnant at the time of enrollment.

Skeletally immature patients that require surgical treatment to obtain and maintain correction of progressive idiopathic scoliosis (Lenke Type 1 curves), 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.