title: [Prediction of spinal cord decompression after cervical laminoplasty: the SC-line].
abstract: OBJECTIVE
  To report a new index (the SC-line) and a new classification for predicting of postoperative spinal cord decompression after cervical laminoplasty.
  
  
  METHODS
  From March 2008 to August 2009, MRI images of 25 patients treated with cervical laminoplasty were retrospectively studied. Using T2-weighted images of the cervical spine, point A was anterior point of the spinal cord at inferior endplate level of cranial compressed vertebra. Point B was anterior point of the spinal cord at superior endplate level of caudal compressed vertebra. The SC-line was defined as a line that connects A and B. Posterior surface of compressor at compression level did not exceed the line in Type I, connected the line in Type II, and exceeded it in Type III. Twenty-five patients who underwent cervical laminoplasty were classified into 3 groups according to the SC-line classification. The posterior shift of the spinal cord after the posterior decompression procedure was evaluated by using a modified gradation of degree of anterior spinal cord compression by MRI finding. The relationship between the degree of anterior spinal cord compression after surgery and the SC-line types were analyzed.
  
  
  RESULTS
  Preoperative cervical SC-line classification showed high correlations to the degree of spinal cord decompression. There were 3.82 ± 0.39 points in Type I before surgery, 3.90 ± 0.32 points in Type II, and 4.00 ± 0.00 points in Type III, respectively. After surgery, there were 1.15 ± 0.50 points in Type I, 2.70 ± 0.48 points in Type II, and 3.50 ± 0.55 points in Type III, respectively. Significant differences were found between each Type (F = 42.49, P < 0.01; Type I vs. Type II: P < 0.01; Type I vs. Type III: P < 0.01; Type II vs. Type III: P = 0.038).
  
  
  CONCLUSIONS
  SC-line can be used to predict the degree of postoperative spinal cord decompression following cervical laminoplasty.
authors.affiliation: Department of Orthopaedic Surgery, Wenzhou Medical College, Wenzhou, China. xiangyangwang@126.com
authors.forename: Xiang-yang
authors.initials: XY
authors.lastname: Wang
authors.forename: Hua-zi
authors.initials: HZ
authors.lastname: Xu
authors.forename: Yong-long
authors.initials: YL
authors.lastname: Chi
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Qi-shan
authors.initials: QS
authors.lastname: Huang
authors.forename: Fang-min
authors.initials: FM
authors.lastname: Mao
authors.forename: Wen-fei
authors.initials: WF
authors.lastname: Ni
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery*; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome