title: C1-C2 posterior fixation: are 4 screws better than 2?
abstract: BACKGROUND
  Several types of C1-C2 fixation techniques have been described over the years in order to treat atlantoaxial instability.
  
  
  OBJECTIVE
  To compare the pros and cons of the most popular C1-C2 posterior fixation used today: C1 lateral mass-C2 pedicle screw and rods (Harms) and transarticular screw (Magerl) fixations.
  
  
  METHODS
  Retrospective review of 122 patients who underwent Harms or Magerl fixation for atlantoaxial instability. Surgical, clinical, and radiological outcomes were compared in the 2 groups.
  
  
  RESULTS
  123 operations were performed, of which 47 were by the Harms technique (group H) and 76 by the Magerl technique (group M). No significant differences were found in duration of surgery, blood loss, postoperative pain, and length of hospitalization. Postoperatively, neck pain, C2-radiculopathy, and hand function improved in both groups, with better, but not statistically significant, results for group H. The intraoperative complication rate was 2.1% in group H and 21% in group M (P < .05); postoperative complication rate was 10.6% in group H and 21% in group M (P > .05). The major complications were vertebral artery injury (2.1% in group H, 13.1% in group M, P = .05) and screw fracture (2.1% in group H, 9.2% in group M, P > .05). Fusion rate at the end of follow-up was not significantly higher in group H. C1-C2 range of movements in flexion/extension at the end of follow-up was lower in group H (P = .017).
  
  
  CONCLUSIONS
  Magerl with posterior wiring and Harms techniques are both effective options for stabilizing the atlantoaxial complex. However, the Harms technique appears to be safer, to have fewer complications, and to demonstrate a more robust long-term fixation.
authors: Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom. piverg@yahoo.it
authors: Pierluigi
authors: P
authors: Vergara
authors: Jarnail Singh
authors: JS
authors: Bal
authors: Adrian Thomas
authors: AT
authors: Hickman Casey
authors: Hugh Alan
authors: HA
authors: Crockard
authors: David
authors: D
authors: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001268:Atlanto-Axial Joint / Q000601:surgery*; D001863:Bone Screws; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D055815:Young Adult