title: Transuncovertebral joint screw placement: technical note.
abstract: Although a C2 pedicle screw and a C1-2 transarticular screw are the most rigid anchors, these screws cannot be used in cases with bilateral high-riding vertebral arteries. The authors describe their recent experience using a novel method of C2-3 transuncovertebral joint screw placement for occipitocervical fixation.
  
  
  
  A 67-year-old patient suffered myelopathy due to instability at C1-2. The patient had bilateral high-riding vertebral arteries that precluded the use of a C2 pedicle screw or a C1-2 transarticular screw.
  
  
  
  A C2-3 transuncovertebral joint screw was applied bilaterally under 3D navigation guidance. The patient's postoperative course was uneventful, and his neurological status improved after the surgery. Bony fusion was achieved after the surgery.
  
  
  
  This is the first report to describe the technique of transuncovertebral joint screw. Using a C2-3 transuncovertebral joint screw, a long screw could be used, and it provided an anchor at C3 and C2 from a posterior approach.
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan. takigawa2004@yahoo.co.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Takigawa
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Morita
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimoto
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama, 700-8558, Japan.
authors.forename: Ozaki
authors.initials: O
authors.lastname: Toshifumi
mesh_terms: D000368:Aged; D002574:Cervical Vertebrae / Q000601:surgery*; D006801:Humans; D008297:Male; D065289:Pedicle Screws; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods
keywords: Cervical pedicle screw; Cervical spine; Navigation surgery; Transarticular screw; Uncovertebral joint