title: Spinal cord shift on magnetic resonance imaging at 24 hours after cervical laminoplasty.
abstract: METHODS
  A prospective study in 19 patients after cervical laminoplasty, using magnetic resonance imaging.
  
  
  OBJECTIVE
  To evaluate the value of spinal cord shift at 24 hours after cervical laminoplasty.
  
  
  BACKGROUND
  Postoperative C5 palsy is a noticeable complication within 1 week after cervical laminoplasty. The root tethering due to the posterior shift of the spinal cord after laminoplasty was reported as one of the causes of C5 palsy. However, the spinal cord shift after surgery within 1 week is unknown.
  
  
  METHODS
  The posterior shift of the spinal cord was measured in 19 consecutive patients on magnetic resonance images at 24 hours and 2 weeks after cervical laminoplasty.
  
  
  RESULTS
  The mean posterior shift of the spinal cord at 24 hours was 2.8 mm, with the maximum at the C5 level, decreasing to 1.9 mm at 2 weeks. The posterior shift of the spinal cord at C5 was correlated with the amount of the dura mater at C4, C5, and C6 levels. In a patient with right C5 palsy, posterior shift at C5 level was 5.5 mm, decreasing to 3.0 mm at 2 weeks after surgery. The posterior shift of the spinal cord was not correlated with the sagittal alignment.
  
  
  CONCLUSIONS
  The posterior shift of the spinal cord at 24 hours had a tendency to shift more posteriorly than that observed at 2 weeks after cervical laminoplasty. C5 palsy may be prevented if the expansion of dura mater, which is strongly correlated with the posterior shift, can be controlled.
authors.affiliation: Department of Orthopaedic Surgery, Akita Social Insurance Hospital, Noshiro, Akita, Japan. shioortho@k4.dion.ne.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiozaki
authors.forename: Hironori
authors.initials: H
authors.lastname: Otsuka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nakata
authors.forename: Toru
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Kazunari
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ono
authors.forename: Takuya
authors.initials: T
authors.lastname: Numasawa
authors.forename: Kanichiro
authors.initials: K
authors.lastname: Wada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Toh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020516:Brachial Plexus Neuropathies / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods; D018450:Disease Progression; D004388:Dura Mater / Q000473:pathology / Q000503:physiopathology; D004487:Edema / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects* / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010243:Paralysis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D011446:Prospective Studies; D011843:Radiculopathy / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D013116:Spinal Cord / Q000033:anatomy & histology / Q000503:physiopathology*; D013126:Spinal Nerve Roots / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D055009:Spondylosis / Q000601:surgery*; D013997:Time Factors; D034941:Upper Extremity / Q000294:innervation / Q000503:physiopathology