Treatment of Mature/Maturing Patients with Adolescent Idiopathic Scoliosis (Sanders ≥ 5) Using a Unique Anterior Scoliosis Correction Technique

Abstract

Anterior vertebral body tethering (VBT) in growing children has been reported as an alternative to fusion for thoracic idiopathic scoliosis. Anterior scoliosis correction (ASC) is our multi-year, multi-generational advancement upon VBT and is a “de-tethering,” not tethering, procedure. ASC incorporates cords/screws similarly to VBT but is a technique that allows for large derotation, curve correction, and restoration of kyphosis using anterior longitudinal ligament complex release (ligament, annular capsule, and disc). It has been used to treat adolescents with minimal or no growth remaining. In this retrospective IRB-approved analysis, we report outcomes of an early cohort of skeletally maturing/mature (Sanders ≥ 5) patients undergoing ASC. Methods: Inclusion criteria: patients with AIS, at least one operative curve 35-70°, Sanders ≥ 5, age ≤ 21 years, minimum 2-year follow-up or failure before. Forty-nine patients with 82 treated curves with surgery from January 2015 to December 2017 met the criteria and were reviewed. Mean follow-up was 30.3 months range 24 to 50 months. Average age at surgery was 15.2 years. Results: The average coronal correction was 65.5% for thoracic curves and 66.7% for lumbar curves. 71.4% of patients with thoracic curves received at least 1 thoracic disc release. Kyphosis (T5-T12) calculated 3D corrected from average 2° pre to 34° post-op. Clinical success (final curve ≤ 30°) was achieved in 45/49 (92%) patients and in 78/82 curves (95%). One unanticipated revision was recommended but not performed. Conclusion: The 2-4 year results of ASC in maturing and mature patients with AIS demonstrated average curve correction of 65.5% in thoracic and 66.7% in lumbar curves. Clinical success with residual curves ≤ 30° was achieved in 47/49 (96%) of all thoracic curves and 31/33 (94%) of all lumbar curves. Average 3D thoracic kyphosis corrected from 2° pre to 34° post.