C1-C2 Posterior Fixation: Are 4 Screws Better Than 2?

Neurosurgery 71[ONS Suppl 1]:ons86–ons95, 2012 

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 groupM(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).

CONCLUSION: 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.

How I do it: cervical lateral mass screw fixation

Acta Neurochir. DOI 10.1007/s00701-011-1068-4

Cervical lateral mass screw fixation is indicated for the treatment of cervical subaxial C3-C7 lesions associated with instability.

Method The authors first describe the surgical anatomy of the subaxial cervical posterior approach. Then the Magerl technique is detailed. In particular, tricks to avoid complications are presented. The ideal screw entry point, direction, size and exit point are mentioned. A surgical video, artist’s drawings and a radiological case report are included.

Conclusion The Magerl technique is a safe and effective lateral mass fixation technique. Respecting anatomical landmarks is crucial to avoid nerve root, vertebral artery and facet joint injury.