title: Assessing range of cervical rotation after laminoplasty using axial CT.
abstract: OBJECTIVE
  Although many authors have reported on cervical range of motion after laminoplasty, they have focused on flexion and extension based on lateral radiographs, not on axial rotation. In this study, we assessed cervical rotation from C1 to T1 after laminoplasty using computed tomography.
  
  
  METHODS
  Eighteen consecutive patients with cervical myelopathy who had undergone laminoplasty were observed. Patient was placed in the supine position on the computed tomography scan table. After the scans in this neutral position were completed, the patient actively rotated his neck as far as possible taking care that the shoulders remained in the horizontal plane. We measured the C1 to T1, C1 to C2, and C2 to T1 rotation angles preoperatively, and at 2 weeks and 6 months after surgery.
  
  
  RESULTS
  The average C1 to T1 rotation angles preoperatively were 46 degrees on the right and 45 degrees on the left. The percentage of C1 to C2 rotation during global cervical rotation (C1 to T1) was 62%. C1 to T1 rotation angle significantly decreased at two weeks after surgery but recovered to almost preoperative levels (11% decreases) by 6 months after surgery with no difference between right and left motion. The average C2 to T1 subaxial rotation angles did not significantly decreased after surgery.
  
  
  CONCLUSIONS
  Rotation angle after laminoplasty decreased slightly at 2 weeks after surgery but recovered almost to preoperative levels by 6 months. Subaxial rotation (C2 to T1) angles did not significantly decreased after surgery.
authors.affiliation: Okayama University Hospital of Medicine and Dentistry, Okayama city, Japan. yoshihisa64@hotmail.com
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Masato
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Haruo
authors.initials: H
authors.lastname: Misawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Takigawa
authors.forename: Hisanori
authors.initials: H
authors.lastname: Ikuma
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D000368:Aged; D001175:Arthrography / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology* / Q000601:surgery; D019299:Decompression, Surgical / Q000009:adverse effects / Q000592:standards; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D013117:Spinal Cord Compression / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods*; D021801:Zygapophyseal Joint / Q000502:physiology / Q000601:surgery