Efficacy of Anterior Vertebral Body Tethering in Skeletally Mature Children with Adolescent Idiopathic Scoliosis: A Preliminary Report

Background: Anterior vertebral body tethering (AVBT) offers a dynamic fusionless correction option for children with adolescent idiopathic scoliosis (AIS). Few existing clinical studies evaluating novel AVBT in skeletally immature children have questioned the midterm efficacy with concerns of overcorrection and curve progression with remaining growth. The current study investigates the effect of this technique in skeletally mature children (Risser >= 4 and Sanders >= 7) with AIS with limited remaining growth potential. Methods: We evaluated skeletally mature children with MS who underwent the AVBT technique for a single structural major curve between 40 degrees and 80 degrees with >50% flexibility on dynamic radiographs and a minimum of 1 year of follow-up. Pertinent clinical and radiographic data collected include skeletal maturity, curve type, Cobb angle, sagittal parameters, and a patient-reported outcome measure Scoliosis Research Society-22 (SRS-22) questionnaire. Results: All 10 children were female with a mean age of 14.9 +/- 2.7 years at the time of surgery. The mean followup was 24.1 +/- 3.6 months. The mean Risser and Sanders scores were 4.2 +/- 0.6 and 7.2 +/- 0.6, respectively. Three patients had major thoracic curves, and 7 patients had thoracolumbar/lumbar curves. Cranial and caudal instrumented levels were T5 and L4. Mean preoperative Cobb's angle was 52.0 degrees +/- 11.6 degrees and was corrected to 15.9 degrees +/- 6.8 degrees on the first erect postoperative radiograph, with stabilization of corrected curve at the 1-year follow-up (mean Cobb's angle of 15.3 degrees +/- 8.7 degrees). Mean preoperative and postoperative SRS-22 scores were 78.0 +/- 3.2 and 92.5 +/- 3.1, respectively (P < .01). No complications were noted until the last follow-up. Conclusion: Our preliminary experience with this novel AVBT as an alternative technique to fusion to stabilize progressive idiopathic scoliosis in skeletally mature children is promising.