CurrentUnitedHealthcarePolicy CS170KS.02

Vertebral Body Tethering for Scoliosis (for Kansas Only)

Medical policy governing use of vertebral body tethering (VBT) for adolescent idiopathic scoliosis; applies only to UnitedHealthcare Community Plan members in Kansas and to procedures performed in Kansas.

Policy Summary

PayerUnitedHealthcare Community Plan

PolicyVertebral Body Tethering for Scoliosis (for Kansas Only)

Policy CodePolicy CS170KS.02

Change TypeRevised coverage criteria and added codes

Effective DateMay 1, 2026

Next Review Date

Key ActionDocument failed conservative management and provide Cobb angle, bending-film correction, and Sanders score evidence plus facility, surgeon, and IRB study investigator documentation to support medical necessity for VBT.

SourceLink

POLICY UPDATE CHANGES

Revised language to indicate VBT surgery may be medically necessary for idiopathic scoliosis when all specified clinical, facility, surgeon, research participation, and shared decision-making criteria are met.

Added revision surgery criteria for VBT (tether breakage/hardware failure, under- or over-correction, removal of tether/anchor screws for complications).

Added medical records and documentation requirements to support medical necessity.

Added CPT codes 0790T and 22838 to Applicable Codes.

Archived previous policy version CS170KS.01.

45-65Cobb angle range for index (major) curve eligible for VBT

2-5

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Medical Necessity Criteria for Vertebral Body Tethering (VBT)

Medically Necessary — Initial VBT for Idiopathic Scoliosis

VBT may be medically necessary for idiopathic scoliosis when ALL of the following are met:

Clinical criteria

Physician documentation establishes failed conservative management (e.g., bracing, observation, or physical therapy) prior to the initial procedure with curvature progression to at least 45 degrees.
The Cobb Angle of the major coronal curve is 45 to 65 degrees for the single curve planned for surgery and none of the spinal curves present are greater than 65 degrees.
Skeletal immaturity defined by the Sanders Maturity Score of 2 to 5.
The Cobb Angle decreases in magnitude to 30 degrees or less on bending films.
Osseous structure is dimensionally adequate to accommodate screw fixation.
Instrumentation limits
- The VBT instrumentation does not extend above T4.
- The VBT instrumentation does not extend below L4.

Facility and perioperative capabilities

An established, on-site surgical pediatric scoliosis program.
Inpatient pediatric physical therapy is available for post-operative training.
Intraoperative advanced imaging capability.
A pediatric anesthesiologist on staff.
A pediatric intensive care unit.

Surgeon and research participation requirements

The surgery will be performed by a pediatric orthopedic spine surgeon with experience in scoliosis and procedures such as VBT, who has determined the procedure is appropriate for the individual.
The pediatric orthopedic spine surgeon is listed as an investigator on a prospective research study being performed at the pediatric spine center that has an approved Institutional Review Board protocol actively recruiting participants for VBT utilizing The Tether™ Vertebral Body Tethering System (FDA Humanitarian Device Exemption), and the member is a study cohort candidate.
The individual and family have engaged in a Shared Decision-Making conversation with the pediatric orthopedic spine surgeon.

All of the above clinical, facility, and surgeon/research participation requirements must be satisfied for initial VBT to be considered medically necessary.

Medically Necessary — Revision VBT Surgery

Revision surgery for VBT may be medically necessary when ANY of the following are present:

ANY of the following

Tether breakage or other hardware failure.
Under- or over-correction of curves.
Removal of tether and/or anchor screws for surgical complication (e.g., impingement on vital organs, infection, intractable pain).

Not Medically Necessary

VBT is not medically necessary when the above criteria are not met.

ALL of the following

Any case that fails to meet all listed medical necessity criteria for initial VBT (see Medically Necessary section).

Evidence-derived Conclusions and Clinical Considerations

Evidence-derived conclusions and clinical considerations

Summarized conditions under which VBT evidence shows outcomes or concerns:

ALL of the following

VBT reduces coronal Cobb angle in most series with mean reductions often ~20–26° at minimum two-year follow-up (multiple systematic reviews and meta-analyses).
VBT is associated with higher rates of mechanical complications (tether breakage) and higher revision/conversion rates compared with PSF in comparative series.
Short- to mid-term evidence (mostly retrospective cohort studies, registries, and case series) is of low-to-moderate quality; longer-term data to skeletal maturity are limited or absent.
Outcomes vary by patient factors

Numeric and Clinical Thresholds

Clinical and procedural thresholds

Index Cobb angle for surgical candidacyMajor coronal curve 45 to 65 degrees; no spinal curve >65 degrees

Bending film correctionCobb angle decreases to 30 degrees or less on bending films

Sanders skeletal maturitySanders Maturity Score 2 to 5

Follow-up horizon for tether breakage (observed)Increased tether breakage observed over 24–36 months (e.g., ~19% at 24 months and ~50% by 36 months in registry data)

Clinical success definition (used in some studies)Residual Cobb angle ≤ 35° at latest follow-up

Instrumented level limitsVBT instrumentation must not extend above T4 or below L4

Procedure and Applicable CPT Codes

Procedure Codes referencedCPT

0656T	Anterior lumbar or thoracolumbar vertebral body tethering; up to 7 vertebral segments.
0657T	Anterior lumbar or thoracolumbar vertebral body tethering; 8 or more vertebral segments.
0790T	Revision (e.g., augmentation, division of tether), replacement, or removal of thoracolumbar or lumbar vertebral body tethering, including thoracoscopy, when performed.
22836	Anterior thoracic vertebral body tethering, including thoracoscopy, when performed; up to 7 vertebral segments.
22837	Anterior thoracic vertebral body tethering, including thoracoscopy, when performed; 8 or more vertebral segments.
22838	Revision (e.g., augmentation, division of tether), replacement, or removal of thoracic vertebral body tethering, including thoracoscopy, when performed.
22899	Unlisted procedure, spine.

Applicable CPTCPT

0790T	Newly added code (policy added this CPT) — specific descriptor not provided in excerpt
22838	Newly added code (policy added this CPT) — specific descriptor not provided in excerpt

Prior Authorization, Documentation, and Billing Requirements

Prior Authorization

Facility and surgeon requirements

Procedure must be performed at a facility that has an established on-site pediatric scoliosis surgical program, inpatient pediatric physical therapy, intraoperative advanced imaging, a pediatric anesthesiologist on staff, and a pediatric intensive care unit; the operating surgeon must be a pediatric orthopedic spine surgeon experienced in scoliosis and VBT and listed as an investigator on an IRB‑approved, actively recruiting prospective study using The Tether™ system.

Facility capabilities required: on-site pediatric scoliosis program; inpatient pediatric physical therapy; intraoperative advanced imaging; pediatric anesthesiologist; pediatric ICU.
Surgeon requirements: pediatric orthopedic spine surgeon with experience in scoliosis and VBT; listed investigator on an IRB‑approved prospective study actively recruiting for The Tether™.

Prior Authorization

Coverage requires meeting all clinical and facility criteria

Coverage and prior authorization require documentation that ALL listed clinical and facility criteria are met; submit the listed procedure codes with supporting clinical documentation including failed conservative management with progression to ≥45°, Cobb and bending film measurements, Sanders score, imaging showing osseous adequacy, and confirmation that instrumentation levels are within T4–L4.

Key Terms and Definitions

Definitions

Cobb AngleObjective radiographic measurement of spinal curvature used to quantify scoliosis angle.

Lenke Classification SystemSystem classifying adolescent idiopathic scoliosis curve types (1–6) with sagittal thoracic and lumbar modifiers to guide surgical planning.

Institutional Review Board (IRB)Independent ethics committee that reviews and monitors clinical research involving human participants.

Sanders Maturity ScoreA skeletal maturity staging system (Sanders Skeletal Maturity Staging System); policy requires Sanders score 2 to 5 to define skeletal immaturity for VBT candidacy.

Shared Decision-MakingCollaborative process between provider and patient/family to make healthcare decisions considering evidence, clinician expertise, and patient values; documented discussion is required.

Tether breakage

Clinical and Administrative Background

Adolescent idiopathic scoliosis (AIS) is a progressive lateral and rotational curvature of the spine occurring in patients aged approximately 10–18 years and is defined radiographically by a Cobb Angle of at least 10°. Progressive curves that reach the surgical range in adolescence are associated with long‑term sequelae including pulmonary compromise, disability, pain, and reduced quality of life if left untreated; curves that exceed skeletal maturity (≈ >40°–45°) are likely to progress into adulthood (AIS natural history and risks). [[9],[10]]

Vertebral body tethering (VBT) is a fusion‑sparing, growth‑modulation surgical technique performed by an anterior thoracotomy, thoracoscopic, or mini‑open approach. The procedure secures vertebral body screws and tensioned flexible cords across the convex side of the curve so that asymmetric loading slows growth on the compressed side while allowing continued growth on the convex side, with the goal of correcting deformity while preserving spinal motion. VBT may use single or double cords and can be applied to thoracic, thoracolumbar, or lumbar curves; revision to replace, remove, or augment hardware is sometimes required for complications or inadequate correction. [[9],[18]]

Compared with the conventional standard of care, posterior spinal fusion (PSF), VBT offers potential advantages reported in many series including better preservation of spinal range of motion, reduced estimated blood loss, shorter instrumentation levels, and faster early recovery. However, comparative studies and pooled reviews also show less reliable and smaller radiographic curve correction, and substantially higher rates of mechanical complications, reoperation, and conversion to fusion in many series. Systematic reviews and meta‑analyses report mean Cobb reductions at ~two years but an overall complication rate in the range of ~20–30% and tether breakage reported variably across studies (single‑study and pooled estimates range broadly); conversion to PSF and reoperation rates are consistently higher than for PSF. These tradeoffs are central to candidate selection and counseling. [[14],[13],[44],[46]]

Clinical evidence for VBT is evolving and is largely composed of prospective registries, single‑center cohorts, and retrospective comparative series with limited long‑term follow‑up to skeletal maturity. Some prospective studies (for example FDA IDE and other multicenter cohorts) report short‑term clinical success (e.g., ~75% success at two years by the IDE study definition of Cobb <35° and no reoperation), but larger series and registry data document increasing tether breakage and reoperation rates with longer follow‑up (Kaplan–Meier estimates and multi‑center reports show substantive increases by 24–36 months and beyond). Reported pulmonary and perioperative complications (pleural effusion, chylothorax, pneumothorax) and device‑mechanical failures are notable and can be more common than with PSF in some reports. Overall evidence quality is low‑to‑moderate and longer‑term, comparative, multicenter data to skeletal maturity are limited. [[18],[19],[35],[36],[44]]

Policy Updates and Material Changes

2026-05-01Policy revision — coverage criteria updatedLatest

Revised coverage rationale to specify detailed clinical thresholds and facility/surgeon/research participation requirements for initial VBT (including failed conservative management with progression to ≥45°; Cobb 45–65° for planned single curve; Sanders score 2–5; bending film correction to ≤30°; osseous adequacy; instrumentation limits T4–L4) and added documentation expectations; this is a material change.

2026-05-01Policy revision — revision surgery criteria added

Added criteria for when revision VBT surgery may be medically necessary (tether breakage/hardware failure, under- or over-correction, removal of tether/anchor screws for complications); material change.

Policy Summary

PayerUnitedHealthcare Community Plan

PolicyVertebral Body Tethering for Scoliosis (for Kansas Only)

Policy CodePolicy CS170KS.02

Change TypeRevised coverage criteria and added codes

Effective DateMay 1, 2026

Next Review Date

SourceLink

On This Page

Documentation Required

Demonstrate failed conservative management and curve progression

Document prior conservative management (e.g., bracing, observation, or physical therapy) and show physician‑documented progression of the curve to at least 45 degrees before the index VBT procedure.

Documentation must show type of conservative therapy and objective evidence of curvature progression to ≥45° prior to surgery.

Documentation Required

Provide radiographic measurements

Provide standing and bending radiographs with Cobb angle measurements demonstrating the index major coronal curve is 45–65°, bending film correction to 30° or less, and that no spinal curve exceeds 65°.

Include standing (first erect) Cobb measures and fulcrum/bending film Cobb showing reduction to ≤30°.
Document that no spinal curve present is greater than 65°.

Documentation Required

Medical record documentation must support medical necessity

Maintain medical records that fully support medical necessity: relevant medical history, physical exam, diagnostic test/procedure results, and legible records that must be made available upon request for review.

Records should include history of conservative treatment, imaging, Sanders/Risser staging, surgeon notes, and consent/shared decision documentation.
Documentation must be legible and retrievable for prior authorization or post‑payment review.

Documentation Required

Informed consent and patient counseling

Obtain and document informed consent and counseling that explicitly addresses limited long‑term evidence, the high incidence of tether breakage, potential need for revision or conversion to posterior spinal fusion, and pulmonary and mechanical perioperative risks.

Counsel that tether breakage rates and higher revision/conversion rates have been reported and may affect outcomes.
Discuss pulmonary risks (e.g., pleural effusion, pneumothorax, chylothorax) and other mechanical complications.

Documentation Required

Patient selection considerations

Document patient selection rationale including skeletal maturity (Risser and/or Sanders), curve magnitude and flexibility, Lenke curve classification, and specific reasons for choosing VBT over posterior spinal fusion given differing outcomes and complication profiles.

Include Risser and Sanders staging, Lenke classification, preoperative Cobb angles, and bending/fulcrum flexibility measurements.
Record the clinical rationale comparing expected benefits and risks of VBT versus PSF for this patient.

Denial Risk

Risk of later revision or fusion

Be aware that a substantial proportion of patients may require additional surgery, including revision or conversion to posterior spinal fusion; absence of demonstrated long‑term comparative benefit and higher revision rates may result in coverage denial when criteria are not met.

Reported conversion to PSF and revision rates vary across studies (examples: 7–16% conversion/revision ranges; tether breakage rates up to ~50% by 36 months).
Lack of meeting all medical necessity criteria may lead to services being considered not medically necessary.

Documentation Required

Surgeon research participation requirement

Surgeon must be listed as an investigator on an IRB‑approved, actively recruiting prospective study for VBT using The Tether™ system and the patient must be a study cohort candidate; include documentation of the IRB protocol and investigator status with the authorization request.

Attach evidence of the IRB‑approved protocol and the surgeon’s investigator listing and confirm the study is actively recruiting participants for The Tether™.

Denial Risk

Denial if criteria not met / Denial if criteria unmet

Requests that do not meet the listed clinical, facility, surgeon, or research participation criteria will be considered not medically necessary and may be denied or subject to denial upon review.

Denial applies if any required element (clinical thresholds, facility capabilities, surgeon experience/IRB investigator status, shared decision‑making) is missing.
Policy explicitly states VBT is not medically necessary when the above criteria are not met.

Given the mixed outcomes and complication profile, current guidance and this policy emphasize careful patient selection, procedures performed by experienced pediatric spinal surgeons in specialized centers, rigorous informed consent and shared decision‑making with patients/families, and the value of conducting VBT within approved prospective research or registries where feasible. Clinicians should counsel families about the limited long‑term evidence, the relatively high incidence of tether breakage and higher revision/conversion rates versus PSF, and the realistic likelihood that some patients will require additional surgery. These considerations underpin the policy’s defined clinical thresholds and facility/surgeon requirements for coverage. [[10],[58],[59],[60]]