title: Safety of atlantoaxial fusion using laminar and transarticular screws combined with an atlas hook in a patient with unilateral vertebral artery occlusion (case report).
abstract: OBJECTIVE
  A disadvantage of transarticular and C2 pedicle screws is vertebral artery (VA) injury as a result of screw misplacement. If unilateral occlusion of the VA is present, VA injury of the dominant side will cause fatal complications as a result of collateral flow insufficiency. Several authors have recently reported the usefulness of C2 laminar screws because of their safety on VA injury. We used transarticular and C2 laminar screws combined with the atlas hook in a patient with C1-2 instability and unilateral VA occlusion, in order to reduce the risk of further VA injury.
  
  
  METHODS
  A 64-year-old woman with rheumatoid atlantoaxial subluxation complained of cervical myelopathy and neck pain. Preoperative MR angiography showed a left side VA occlusion.
  
  
  METHODS
  The patient underwent atlantoaxial, posterior fusion using a transarticular screw on the side of the occlusion and a C2 laminar screw on the dominant side combined with a bilateral atlas hook. The transarticular screw was inserted using a navigation system and image intensifier, and the laminar screw was inserted free hand. Bone grafting from the iliac crest was performed.
  
  
  CONCLUSIONS
  Transarticular and C2 laminar screws fixation combined with the atlas hook in a patient with unilateral VA occlusion is a useful technique, in order to reduce the risk of further VA injury.
authors.affiliation: Science of Functional Recovery and Reconstruction, Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Science, Okayama city, Japan. yoshihisa64@hotmail.com
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Masato
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Haruo
authors.initials: H
authors.lastname: Misawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Takigawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ito
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
mesh_terms: D001157:Arterial Occlusive Diseases; D001172:Arthritis, Rheumatoid / Q000601:surgery; D001268:Atlanto-Axial Joint / Q000601:surgery*; D001863:Bone Screws / Q000009:adverse effects; D005260:Female; D006801:Humans; D008875:Middle Aged; D013122:Spinal Diseases / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D014711:Vertebral Artery