title: Spinal cord cross-sectional area during flexion and extension in the patients with cervical ossification of posterior longitudinal ligament.
abstract: OBJECTIVE
  The pathomechanism of cervical myelopathy due to cervical ossification of posterior longitudinal ligament (C-OPLL) remains unclear. No previous literature has quantified the influence of dynamic factors on cervical myelopathy due to C-OPLL. The purpose was to investigate the influence of dynamic factors on the spinal column in the patients with C-OPLL using CT scan after myelography (MCT).
  
  
  METHODS
  The study included 41 patients with cervical myelopathy due to C-OPLL. An MCT was done during neck flexion and extension, and spinal cord cross-sectional areas (SCCSA) were measured at each disc level between C2/3 and C7/T1. Ossification morphology at each segment was divided into three groups, connection department, coating part, and non-connection department of OPLL group. Dynamic changes of SCCSA in each group of ossification morphology were calculated. The relationship between clinical results and SCCSA at the narrowest level was investigated.
  
  
  RESULTS
  MCT showed SCCSA changes during neck extension; 7.4 ± 5.1 mm(2) in the connection department, 5.8 ± 6.0 mm(2) in the coating part, and 6.7 ± 6.4 mm(2) in the non-connection department of OPLL group. There difference was not statistically significant. There was a weak correlation between the JOA score and SCCSA at the narrowest level (R = 0.49). There was no significant correlation between the recovery rate of JOA score and SCCSA at the narrowest level (R = 0.37).
  
  
  CONCLUSIONS
  Dynamic factors are seen both in cervical myelopathy patients with the continuous type of OPLL and others. Deterioration of myelopathy could be induced by motion effects even in the connection department of OPLL.
authors: Department of Orthopedic Surgery, Chubu Rosai Hospital, 1-10-6 Koumei, Minato-ku, Nagoya, Aichi, Japan, keiort@aol.com.
authors: Keigo
authors: K
authors: Ito
authors: Yasutsugu
authors: Y
authors: Yukawa
authors: Masaaki
authors: M
authors: Machino
authors: Fumihiko
authors: F
authors: Kato
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009192:Myelography; D017887:Ossification of Posterior Longitudinal Ligament / Q000150:complications / Q000000981:diagnostic imaging*; D016059:Range of Motion, Articular; D013116:Spinal Cord / Q000000981:diagnostic imaging*; D013118:Spinal Cord Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed
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