title: Cervical myelopathy caused by C3-C4 spondylosis in elderly patients: a radiographic analysis of pathogenesis.
abstract: METHODS
  A radiographic analysis of elderly patients with cervical spondylotic myelopathy, particularly those with involvement of the C3-C4 level.
  
  
  OBJECTIVE
  To elucidate the potential contributors to the higher incidence of pathology at C3-C4 in the elderly.
  
  
  BACKGROUND
  In this study, the elder patients showed a greater predilection for involvement of the C3-C4 lesion compared with their younger counterparts. No previous study has addressed C3-C4 pathology in elderly patients.
  
  
  METHODS
  This study included 18 patients, 10 men and 8 women, with cervical spondylotic myelopathy caused by C3-C4 disorders (group I). For the purpose of comparison, 18 younger patients (less than 50 years of age) with myelopathy (group II) and 30 volunteers over the age of 65 (group III) were also investigated. Mean age at admission was 73.5 years for group I, 42.4 years for group II, and 73.4 years for group III. Radiographic analysis, using static and dynamic radiographs, was performed to evaluate the morphologic features.
  
  
  RESULTS
  The mean spinal canal diameter for groups I and II was significantly smaller than that for group III. Group I exhibited greater C2-C7 lordosis. The aged population, group I and group III, showed greater C3-C4 angulation associated with C4 forward inclination in neutral standing position as compared with younger patients. Regarding dynamic factors, group I showed the largest segmental motion at C3-C4, and, conversely, the smallest mobility at the lower segments, with significant differences.
  
  
  CONCLUSIONS
  Using radiographic analysis, morphologic features that predispose patients to disorders of the C3-C4 motion segment were evaluated. These features included 1) greater C3-C4 angulation associated with age-related postural change and 2) hypermobility at the C3-C4 segment compensating for decreased mobility at the lower segments.
authors.affiliation: Department of Orthopaedic Surgery, Yokohama Minami Kyosai Hospital, Yokohama, Japan. hmihara@facstaff.wisc.edu
authors.forename: H
authors.initials: H
authors.lastname: Mihara
authors.forename: K
authors.initials: K
authors.lastname: Ohnari
authors.forename: M
authors.initials: M
authors.lastname: Hachiya
authors.forename: S
authors.initials: S
authors.lastname: Kondo
authors.forename: K
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D008297:Male; D011859:Radiography; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000209:etiology; D013128:Spinal Osteophytosis / Q000150:complications* / Q000000981:diagnostic imaging; D013130:Spinal Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology*