title: Cross-Links Do Not Improve Clinical or Radiographic Outcomes of Posterior Spinal Fusion With Pedicle Screws in Adolescent Idiopathic Scoliosis: A Multicenter Cohort Study.
abstract: METHODS
  Retrospective, comparative analysis.
  
  
  OBJECTIVE
  Comparative analysis was performed to determine the differences, if any, between adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) with and without cross-links.
  
  
  BACKGROUND
  Cross-links are frequently used during PSF for AIS. It is unclear whether they provide any advantage for patients with all-pedicle screw constructs.
  
  
  METHODS
  A prospectively collected multicenter database of patients with AIS undergoing spinal fusion was retrospectively queried. Study inclusion criteria were primary PSF with all-pedicle screw fixation (greater than 90% fixation points) and minimum 2 years' follow-up. Collected data included demographics, radiographic measures, complications, Scoliosis Research Society-22r and Spinal Appearance Questionnaire (SAQ) scores.
  
  
  RESULTS
  A total of 500 patients were included (377 cross-link and 123 non-cross-link). Age, body mass index, gender, and preoperative major Cobb angle were not different between groups. Except for a slightly decreased lumbar Cobb angle (2.7°) in the cross-link group, no other radiographic measures were different at follow-up. Complications were not significantly different between groups: 21 of 377 (6%) crosslink and 9 of 123 (7%) non-cross-link. Infection occurred in 1 patient in the cross-link group and none in the non-cross link group. Reoperation occurred in 4 patients, all with cross-links (3 for implant removal and 1 for distal adding-on). Scoliosis Research Society-22r scores, total and individual domains, improved by a similar amount in both groups. At follow-up, parent and patient SAQ appearance scores were not significantly different. The SAQ expectations domain scores were similar for all visits and improved for both patients and parents.
  
  
  CONCLUSIONS
  There do not appear to be significant clinical or radiographic outcome differences in patients with AIS undergoing PSF based on the use of cross-links at 2-year follow-up. Surgeons should consider eliminating cross-links in patients with AIS who have PSF with all-pedicle screw constructs. This may have substantial cost savings without affecting patient outcome.
authors.affiliation: Children's Hospital Colorado Orthopedics Institute, University of Colorado, 13123 East 16th Avenue, Box 060, Aurora, CO 80045, USA. Electronic address: sumeet.garg@childrenscolorado.org.
authors.forename: Sumeet
authors.initials: S
authors.lastname: Garg
authors.affiliation: Children's Hospital Colorado Orthopedics Institute, University of Colorado, 13123 East 16th Avenue, Box 060, Aurora, CO 80045, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Niswander
authors.affiliation: Children's Hospital Colorado Orthopedics Institute, University of Colorado, 13123 East 16th Avenue, Box 060, Aurora, CO 80045, USA.
authors.forename: Zhaoxing
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Children's Hospital Colorado Orthopedics Institute, University of Colorado, 13123 East 16th Avenue, Box 060, Aurora, CO 80045, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Erickson
keywords: Adolescent idiopathic scoliosis; Cross-link; Pedicle screw; Posterior spinal fusion