title: The Classification for Early-onset Scoliosis (C-EOS) Correlates With the Speed of Vertical Expandable Prosthetic Titanium Rib (VEPTR) Proximal Anchor Failure.
abstract: BACKGROUND
  The Classification for Early-onset Scoliosis (C-EOS) was developed by a consortium of early-onset scoliosis (EOS) surgeons. This study aims to examine if the C-EOS classification correlates with the speed (failure/unit time) of proximal anchor failure in EOS surgery patients.
  
  
  METHODS
  A total of 106 EOS patients were retrospectively queried from an EOS database. All patients were treated with vertical expandable prosthetic titanium rib and experienced proximal anchor failure. Patients were classified by the C-EOS, which includes a term for etiology [C: Congenital (54.2%), M: Neuromuscular (32.3%), S: Syndromic (8.3%), I: Idiopathic (5.2%)], major curve angle [1: ≤20 degrees (0%), 2: 21 to 50 degrees (15.6%), 3: 51 to 90 degrees (66.7%), 4: >90 degrees (17.7%)], and kyphosis ["-": ≤20 (13.5%), "N": 21 to 50 (42.7%), "+": >50 (43.8%)]. Outcome was measured by time and number of lengthenings to failure.
  
  
  RESULTS
  Analyzing C-EOS classes with >3 subjects, survival analysis demonstrates that the C-EOS discriminates low, medium, and high speed of failure. The low speed of failure group consisted of congenital/51-90/hypokyphosis (C3-) class. The medium-speed group consisted of congenital/51-90/normal and hyperkyphosis (C3N, C3+), and neuromuscular/51-90/hyperkyphosis (M3+) classes. The high-speed group consisted of neuromuscular/51-90/normal kyphosis (M3N), and neuromuscular/>90/normal and hyperkyphosis (M4N, M4+) classes. Significant differences were found in time (P<0.05) and number of expansions (P<0.05) before failure between congenital and neuromuscular classes.As isolated variables, neuromuscular etiology experienced a significantly faster time to failure compared with patients with idiopathic (P<0.001) and congenital (P=0.026) etiology. Patients with a major curve angle >90 degrees demonstrated significantly faster speed of failure compared with patients with major curve angle 21 to 50 degrees (P=0.011).
  
  
  CONCLUSIONS
  The ability of the C-EOS to discriminate the speeds of failure of the various classification subgroups supports its validity and demonstrates its potential use in guiding decision making. Further experience with the C-EOS may allow more tailored treatment, and perhaps better outcomes of patients with EOS.
  
  
  METHODS
  Level III.
authors.affiliation: *Department of Orthopaedic Surgery, University of California Los Angeles, Los Angeles, CA †Department of Orthopaedic Surgery, Columbia University Medical Center, New York City, NY ‡Department of Orthopaedic Surgery, Harvard University ¶Department of Orthopedic Surgery, Boston Children's Hospital, Boston, MA §The Institute for Spine and Scoliosis, Lawrenceville, NJ ∥Shriners Hospitals for Children §§Department of Orthopedic Surgery, University of Pennsylvania, Philadelphia, PA #Department of Orthopedic Surgery, Washington University in St. Louis, St Louis, MO **Department of Orthopaedic Surgery, University of Colorado Denver, Denver, CO ††Department of Orthopaedic Surgery, University of Tennessee, Memphis, TN ‡‡Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT.
authors.forename: Howard Y
authors.initials: HY
authors.lastname: Park
authors.forename: Hiroko
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Nicholas
authors.initials: N
authors.lastname: Feinberg
authors.forename: David P
authors.initials: DP
authors.lastname: Roye
authors.forename: Wajdi W
authors.initials: WW
authors.lastname: Kanj
authors.forename: Randal R
authors.initials: RR
authors.lastname: Betz
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Cahill
authors.forename: Michael P
authors.initials: MP
authors.lastname: Glotzbecker
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Luhmann
authors.forename: Sumeet
authors.initials: S
authors.lastname: Garg
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Sawyer
authors.forename: John T
authors.initials: JT
authors.lastname: Smith
authors.forename: John M
authors.initials: JM
authors.lastname: Flynn
authors.forename: Michael G
authors.initials: MG
authors.lastname: Vitale
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D019736:Prostheses and Implants; D012189:Retrospective Studies; D012272:Ribs / Q000601:surgery; D012600:Scoliosis / Q000145:classification* / Q000209:etiology / Q000601:surgery; D053441:Suture Anchors; D013997:Time Factors; D014025:Titanium; D017211:Treatment Failure
chemical_list: D014025:Titanium