title: Palsy of the C5 nerve root after midsagittal-splitting laminoplasty of the cervical spine.
abstract: METHODS
  The imaging characteristics of postoperative C5 nerve root palsy after midsagittal-splitting laminoplasty for cervical myelopathy, including those observed on plain radiography, computed tomography, and magnetic resonance imaging, were analyzed.
  
  
  OBJECTIVE
  To investigate the imaging findings that predict occurrence of C5 nerve root palsy after midsagittal-splitting laminoplasty.
  
  
  BACKGROUND
  There have been several reports on imaging findings for postoperative nerve root palsy after open-door laminoplasty. However, there have been no detailed reports on imaging characteristics that predict the occurrence of nerve root palsy after midsagittal-splitting laminoplasty.
  
  
  METHODS
  The study included 45 consecutive patients undergoing midsagittal-splitting laminoplasty with sufficient pre- and postoperative imaging examinations: 27 patients with cervical spondylotic myelopathy (CSM), 14 patients with ossification of the posterior longitudinal ligament (OPLL), and 4 patients with cervical disc herniation. Characteristics of pre- and postoperative plain radiographs, computed tomography scans, and magnetic resonance images were compared between the patients with and those without C5 nerve root palsy.
  
  
  RESULTS
  Palsy of the C5 nerve root developed in 4 patients, and did not develop in 41 patients. Of the four patients with C5 nerve root palsy, one had CSM and the other three had OPLL. The incidence of C5 nerve root palsy involved 3 of 14 patients with OPLL patients (21.4%) and 1 of 31 patients without OPLL (3.2%) (P = 0.08). For both diseases, the patients with palsy tended to have increased postoperative cervical lordosis (P = 0.21). As for anterior compression on the spinal cord at C3, the P value for the comparison between the group with and the group without palsy was 0.07 for preoperative compression and 0.01 for postoperative compression.
  
  
  CONCLUSIONS
  The preliminary data suggest that patients who have OPLL with marked anterior compression on spinal cord at C3 can be at risk for postoperative C5 nerve root palsy after midsagittal-splitting laminoplasty. Also, a postoperative increase in cervical lordosis may be the cause of postoperative nerve root palsy.
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Medical School, Osaka, Japan. yminoda@med.osaka-cu.ac.jp
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Minoda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Sadahiko
authors.initials: S
authors.lastname: Konishi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nagayama
authors.forename: Eisuke
authors.initials: E
authors.lastname: Suzuki
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamano
authors.forename: Kunio
authors.initials: K
authors.lastname: Takaoka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008141:Lordosis / Q000209:etiology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D009333:Neck / Q000000981:diagnostic imaging; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D010243:Paralysis / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D011183:Postoperative Complications / Q000209:etiology; D012720:Severity of Illness Index; D013122:Spinal Diseases / Q000601:surgery*; D013126:Spinal Nerve Roots / Q000293:injuries / Q000503:physiopathology*; D013131:Spine / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed