title: Cervical myelopathy caused by pseudoarthrosis between posterior arch of the atlas and lamina of the axis in Klippel-Feil syndrome: a case report.
abstract: METHODS
  Case report.
  
  
  BACKGROUND
  Cervical myelopathy caused by osteophyte formation appearing at the pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis is extremely rare. To our knowledge, only 2 cases in non-Klippel-Feil syndrome have been reported so far.
  
  
  METHODS
  A 61-year-old man, who was diagnosed as Klippel-Feil syndrome with assimilation between C2 and C3 vertebrae, which were fused in hyperlordosis, suffered cervical myelopathy. Complete bipartition of the atlas was also demonstrated. Massive osteophytes, which severely compressed the spinal cord at the pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis, were seen. Surgical resection of the osteophytes was performed.
  
  
  RESULTS
  The patient had significant clinical improvement after posterior resection of the osteophytes.
  
  
  CONCLUSIONS
  Coincidence of several bony anomalies such as assimilation of C2 and C3, which were fused in hyperlordosis, and the bipartition of the atlas may biomechanically influence the formation of pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis. Because symptoms appeared in the patient's 60s despite congenital bony anomaly, degeneration might contribute to the formation of massive osteophytes. Posterior decompression was effective in this case.
authors.affiliation: Department of Orthopedic Surgery, National Hospital Organization Kobe Medical Center, Kobe, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Sumi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Inui
authors.forename: Koki
authors.initials: K
authors.lastname: Uno
authors.forename: Masato
authors.initials: M
authors.lastname: Takabatake
authors.forename: Kou
authors.initials: K
authors.lastname: Tadokoro
mesh_terms: D001368:Axis, Cervical Vertebra / Q000601:surgery; D001270:Cervical Atlas / Q000601:surgery; D006801:Humans; D007714:Klippel-Feil Syndrome / Q000150:complications*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011542:Pseudarthrosis / Q000150:complications* / Q000175:diagnosis; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000209:etiology*