title: Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one-year results on the first 32 patients.
abstract: OBJECTIVE
  This retrospective chart review evaluates the clinical and radiographic outcomes of anterior vertebral body tethering (VBT) at 1-year follow-up. Anterior VBT offers a fusionless treatment option for skeletally immature patients with adolescent idiopathic scoliosis. It is a growth-modulation technique, which utilizes patients' growth to attain progressive scoliosis correction. Numerous animal models support its promise; however, clinical data remain sparse.
  
  
  METHODS
  Clinical and radiographic data were retrospectively analyzed. We reviewed 32 patients who underwent thoracic VBT with a minimum one-year follow-up. Pertinent clinical and radiographic data were collected. ANOVA, Student's t test and Fisher's exact test were utilized to compare different time points.
  
  
  RESULTS
  32 patients with thoracic idiopathic scoliosis (72 % female) with a minimum one-year follow-up were identified; mean age at surgery was 12 years. All patients were considered skeletally immature pre-operatively; mean Risser score 0.42, mean Sanders score 3.2. Patients underwent tethering of an average of 7.7 levels (range 7-11). Median blood loss was 100 cc. The mean pre-operative thoracic curve magnitude was 42.8° ± 8.0° which corrected to 21.0° ± 8.5° on first erect and 17.9° ± 11.4° at most recent. The pre-operative lumbar curve of 25.2° ± 7.3° demonstrated progressive correction (first erect = 18.0° ± 7.1°, 1 year = 12.6° ± 9.4°, p < 0.00001). Thoracic axial rotation measured 13.4° pre-operatively and 7.4° at the most recent measurement (p < 0.00001). One patient experienced prolonged atelectasis which required a bronchoscopy; otherwise, no major complications were observed.
  
  
  CONCLUSIONS
  Our early results indicate that anterior VBT is a safe and potentially effective treatment option for skeletally immature patients with idiopathic scoliosis. These patients experienced an improvement of their scoliosis with minimal major complications. However, longer term follow-up of this cohort will reveal the true benefits of this promising technique.
  
  
  METHODS
  IV.
authors.affiliation: Shriners Hospitals for Children-Philadelphia, 3551 North Broad Street, 19140, Philadelphia, PA, USA, amersamdani@gmail.com.
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; D015331:Cohort Studies; D005260:Female; D006801:Humans; 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