title: Clinical and radiologic outcome of laminar screw at C2 and C7 for posterior instrumentation--review of 25 cases and comparison of C2 and C7 intralaminar screw fixation.
abstract: BACKGROUND
  The aim of this study is 2-fold: to analyze a clinical case series in which we used laminar screws for cervical posterior instrumentation and to describe the difference between C2 and C7 laminar screws in terms of technique and anatomy.
  
  
  METHODS
  Data were obtained from 25 patients who underwent cervical posterior fixation with intralaminar screws at C2 or C7. C2 intralaminar screw instrumentation was used for 7 patients requiring occipitocervical fixation (basilar invagination [3 patients], C1 unstable bursting fracture [1 patient], C1-C2 instability with occipital assimilation [2 patients], and dystopic os odontoideum [1 patient]), 13 patients with C1-C2 instability, 1 patient with C2-C3 subluxation, and 4 patients undergoing C7 fixation due to pseudoarthrosis or cervical instability after trauma. A total of 34 laminar screws were placed including 1 thoracic laminar screw, and the patients were assessed both clinically and radiographically.
  
  
  RESULTS
  There were no instances where a screw violated the spinal canal nor any hardware fractures noted during the follow-up period. As for perioperative complications, there were 2 cases of postoperative wound infection, 1 case of dural laceration during dissection, and 2 cases of partial dorsal laminar breach. However, there was no neurologic compromise in any of the cases. The fusion success rate was 100%.
  
  
  CONCLUSIONS
  These preliminary results support the use of intralaminar screws for posterior instrumentation at C2 and C7.
authors.affiliation: Department of Neurosurgery, the Catholic University of Korea, Seoul, South Korea. jatagi15@paran.com
authors.forename: Jae Taek
authors.initials: JT
authors.lastname: Hong
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Yi
authors.forename: Jong Tae
authors.initials: JT
authors.lastname: Kim
authors.forename: Chul
authors.initials: C
authors.lastname: Ji
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Ryu
authors.forename: Chun Kun
authors.initials: CK
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000293:injuries*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult