Is vertebral body tethering (CPT: 0657T; 22899) medically indicated for a 14-year-old male patient with adolescent idiopathic scoliosis?

Medical Necessity Determination for Vertebral Body Tethering

Vertebral body tethering (VBT) is NOT medically indicated for this patient because the procedure is considered unproven/investigational by established criteria, and the patient meets clear indications for the gold standard treatment of posterior spinal fusion given his 50-degree curve and skeletal immaturity. 1, 2

Determination: NOT MEDICALLY NECESSARY

The requested procedure (CPT 0657T, 22899) does not meet medical necessity criteria for the following reasons:

Primary Rationale - Unproven Status

• VBT is explicitly classified as unproven by MCG criteria because the effectiveness of this approach has not been established through sufficient high-quality evidence. 3, 4

• The procedure remains investigational with significantly greater variability in outcomes compared to posterior spinal fusion, which is the established gold standard. 3

• While recent case series show promising correction rates up to 70%, these are retrospective studies with limited long-term follow-up, not the level of evidence required to establish a procedure as proven. 3, 4

Clinical Criteria Analysis

This patient clearly meets surgical thresholds for PROVEN intervention:

• 50-degree thoracolumbar curve exceeds the 45-50 degree threshold where surgical intervention is indicated for skeletally immature patients. 1, 2

• At 14 years old with ongoing growth potential, curves >20 degrees have progression likelihood exceeding 70%, and this patient's 50-degree curve has substantial risk of continued progression. 1, 5

• Two years of bracing compliance (22 hours daily) demonstrates failure of conservative management to prevent progression to surgical thresholds. 1

Complication Profile Concerns

VBT carries a significantly different and concerning complication profile:

• Overall complication rate of 23% in meta-analysis, with tether breakage occurring in 21.9% of cases. 4

• Overcorrection occurs in 11% of cases, requiring additional intervention. 6

• Spinal fusion conversion rate of 7.2%, meaning patients may ultimately require the standard procedure anyway after experiencing VBT complications. 4

• Approach-related pulmonary complications occur in 3% of cases. 6

Standard of Care Alternative

Posterior spinal fusion with instrumentation is the appropriate medically necessary procedure:

• This is the established standard surgical approach for curves exceeding 45-50 degrees in skeletally immature patients. 1, 2

• Bone grafting (allograft and/or autograft) achieves solid arthrodesis with predictable outcomes. 1, 2

• Long-term outcomes and effectiveness are well-established through decades of evidence. 3

Pre-Surgical Requirements

Before ANY surgical intervention, the following evaluation is mandatory:

• MRI of the complete spine must be obtained to rule out neural axis abnormalities, particularly given this is a thoracolumbar curve pattern. 7, 1, 2

• Neural axis abnormalities occur in 2-4% of adolescent idiopathic scoliosis patients and can include Chiari I malformation, cord syrinx, cord tethering, or intrinsic spinal cord tumor. 7, 5

• Detection of these anomalies before surgery may significantly influence surgical management and outcomes. 7, 2

Critical Pitfalls to Avoid

• Do not pursue unproven procedures when established effective treatments exist - this patient has a clear indication for posterior spinal fusion, which has predictable outcomes and established long-term safety. 1, 3

• Do not assume VBT is "less invasive" without considering the 23% complication rate and 7.2% conversion to fusion rate - patients may end up with multiple surgeries rather than one definitive procedure. 4

• Do not proceed with any surgical intervention without pre-operative MRI - neural axis abnormalities must be ruled out before surgical planning. 7, 1, 2

Recommended Course of Action

Approve posterior spinal fusion with instrumentation (standard CPT codes for spinal fusion, not VBT codes) contingent on:

• Pre-operative MRI of complete spine without contrast to evaluate for neural axis abnormalities. 7, 1, 2

• Confirmation of skeletal immaturity status (Risser stage) to optimize surgical timing. 1

• Standard pre-operative medical clearance appropriate for major spinal surgery. 2

Deny vertebral body tethering (CPT 0657T, 22899) as investigational/unproven per MCG criteria and lack of established effectiveness compared to standard surgical treatment. 3, 4