title: Clinical study of C3-C4 level surgical cases of cervical spondylosis.
abstract: OBJECTIVE
  The purpose of this study was to elucidate the pathological characteristics of C3-C4 cervical spondylotic myelopathy (CSM).
  
  
  METHODS
  Single-level anterior cervical discectomy and fusion (ACDF) was performed at C3-C4 in 53 patients (38 men, 15 women). The mean duration of preoperative symptoms was 6.0 months. Fifty-three non C3-C4 ACDF patients of our random sample of ACDF patients were compared to the C3-C4 ACDF patients. Clinical outcomes were assessed according to the Japanese Orthopedic Association score (JOA score), the Neurosurgical Cervical Spine Scale (NCSS), and the Nurick scale. And radiological findings including C2-C7 lordosis, C3-C4 range of intervertebral motion (ROM), C2-C7 ROM, and C3-C4%ROM in the cervical spine were evaluated in both groups.
  
  
  RESULTS
  The recovery rates of JOA score and the NCSS in C3-C4 ACDF patients were 62.5% and 62.1%, respectively. The radiological study of C3-C4 ACDF patients showed that they had significant cervical lordosis, and cervical motion was dependent on the C3-C4 segment, which accounted for 39.8% of C2-C7 ROM (total motion).
  
  
  CONCLUSIONS
  In C3-C4 ACDF patients, not only static factors, but dynamic factors (instability) at the C3-C4 level contributed to the major causes of CSM.
authors.affiliation: Department of Neurosurgery, Southern TOHOKU General Hospital, Iwanuma, Miyagi, Japan. Electronic address: masatotomii@ybb.ne.jp.
authors.forename: Masato
authors.initials: M
authors.lastname: Tomii
authors.affiliation: Department of Neurosurgery, Southern TOHOKU General Hospital, Iwanuma, Miyagi, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Mizuno
authors.affiliation: Department of Neurosurgery, Southern TOHOKU Research Institute for Neuroscience, Southern TOHOKU General Hospital, Koriyama, Fukushima, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Itoh
authors.affiliation: Department of Neurosurgery, Southern TOHOKU General Hospital, Iwanuma, Miyagi, Japan; Department of Neurosurgery, Southern TOHOKU Research Institute for Neuroscience, Southern TOHOKU General Hospital, Koriyama, Fukushima, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000601:surgery*; D015331:Cohort Studies; D019299:Decompression, Surgical / Q000379:methods; D017586:Diskectomy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D055009:Spondylosis / Q000150:complications / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Anterior cervical discectomy and fusion; C3–C4 level; Cervical spondylotic myelopathy; Instability