title: The use of C1 lateral mass screws in complex cervical spine surgery: indications, techniques, and outcome in a prospective consecutive series of 25 cases.
abstract: OBJECTIVE
  Direct C1 lateral mass/C2 pars or pedicle screw fixation has been recently proposed as an alternative method to C1-C2 transarticular screw fixation. Although this method seems attractive, there are currently limited clinical data on the use of this technique for multilevel fixation including complex craniocervical reconstructions. The objectives of this study were to assess the safety and the clinical/radiographic outcomes in patients undergoing cervical spine surgery using C1 lateral mass screws (C1-LMS).
  
  
  METHODS
  A prospectively accrued database was reviewed to determine initial presentation, etiology, operations, complications, and clinical/radiologic outcomes.
  
  
  RESULTS
  Twenty-five patients with a mean age of 56 underwent fixation with C1-LMS. Mean follow-up was 12 months. The indications for using C1-LMS instead of C1-C2 transarticular screws were: unfavorable bony or vascular anatomy, tumor destruction, thoracic kyphosis or cervical hyperlordosis, inability to reduce the C1-C2 dislocation intraoperatively and or surgeon preference. Satisfactory stability was achieved in all cases with no neurologic or vascular complications. In one case, the C1 screws breached the medial cortex. Three patients developed transient postoperative C2 neuralgia. One patient had an extended stay in ICU due to respiratory issues.
  
  
  CONCLUSIONS
  On the basis of our experience, proficiency with the use of C1-LMS screw fixation greatly enhances the ability to manage complex atlantoaxial or craniocervical pathologies with low morbidity. This technique should be considered an excellent adjunct or alternative to transarticular screw fixation.
authors.affiliation: Division of Neurosurgery, Spinal Program, Krembil Neuroscience Center, Toronto Western Hospital, University of Toronto, Toronto, Canada.
authors.forename: Thorsteinn
authors.initials: T
authors.lastname: Gunnarsson
authors.forename: Eric M
authors.initials: EM
authors.lastname: Massicotte
authors.forename: Preneshlin V
authors.initials: PV
authors.lastname: Govender
authors.forename: Yoga
authors.initials: Y
authors.lastname: Raja Rampersaud
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D002574:Cervical Vertebrae; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome