title: Anterior vertebral body tethering for idiopathic scoliosis: two-year results.
abstract: METHODS
  Retrospective review.
  
  
  OBJECTIVE
  To report the 2-year results of the initial cohort undergoing anterior vertebral body tethering (VBT).
  
  
  BACKGROUND
  Anterior VBT is a promising new technique with abundant preclinical studies but very few clinical results. It is a growth modulation technique, which utilizes patients' growth to attain progressive correction of their scoliosis. We report 2-year results of the initial cohort undergoing this procedure.
  
  
  METHODS
  After obtaining institutional review board approval, we retrospectively reviewed our first 11 consecutive patients who underwent anterior VBT with 2-year follow-up. We collected pertinent preoperative, intraoperative, and most recent clinical and radiographical data. Student t test and Fisher exact test were utilized to compare different time points.
  
  
  RESULTS
  Eleven patients with thoracic idiopathic scoliosis (8 females) were identified, with a mean age of 12.3 ± 1.6 years. Preoperatively, all were skeletally immature (Sanders mean = 3.4 ± 1.1; Risser mean = 0.6 ± 1.1). All underwent tethering of an average of 7.8 ± 0.9 (range: 7-9) levels, with the most proximal being T5 and the most distal L2. Preoperative thoracic Cobb angle averaged 44.2 ± 9.0° and corrected to 20.3 ± 11.0° on first erect, with progressive improvement at 2 years (Cobb angle = 13.5 ± 11.6°, % correction = 70%; P < 0.00002). Similarly, the preoperative lumbar curve of 25.1 ± 8.7° demonstrated progressive correction (first erect = 14.9 ± 4.9°, 2 yr = 7.2 ± 5.1°, % correction = 71%; P < 0.0002). Thoracic axial rotation as measured by a scoliometer went from 12.4 ± 3.3° preoperatively to 6.9 ± 3.4° at the most recent measurement (P < 0.01). No major complications were observed. As anticipated, 2 patients returned to the operating room at 2 years postoperatively for loosening of the tether to prevent overcorrection.
  
  
  CONCLUSIONS
  Anterior VBT is a promising technique for skeletally immature patients with idiopathic scoliosis. This technique can be performed safely and can result in progressive correction.
  
  
  METHODS
  4.
authors.affiliation: *Shriners Hospitals for Children, Philadelphia, PA †Drexel University College of Medicine, Philadelphia, PA ‡Cooper Medical School of Rowan University, Camden, NJ §Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE; and ¶Institute for Spine & Scoliosis, Lawrenceville, NJ.
authors.forename: Amer F
authors.initials: AF
authors.lastname: Samdani
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ames
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Kimball
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Pahys
authors.forename: Harsh
authors.initials: H
authors.lastname: Grewal
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Pelletier
authors.forename: Randal R
authors.initials: RR
authors.lastname: Betz
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods*; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome