C1-C2 posterior fixation: are 4 screws better than 2?

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Spinal Surgery

Background:

• Atlantoaxial instability necessitates C1-C2 fixation techniques.
• Various posterior fixation methods have been developed for C1-C2 instability.

Purpose of the Study:

• To compare the C1 lateral mass-C2 pedicle screw and rods (Harms) technique with the transarticular screw (Magerl) fixation for atlantoaxial instability.
• Evaluate surgical, clinical, and radiological outcomes of these two popular C1-C2 posterior fixation methods.

Main Methods:

• Retrospective review of 122 patients with atlantoaxial instability undergoing either Harms or Magerl fixation.
• Comparison of surgical duration, blood loss, pain, hospitalization, complication rates, and fusion rates between the two groups.

Main Results:

• No significant differences in surgery duration, blood loss, pain, or hospitalization between Harms and Magerl techniques.
• Harms technique showed significantly lower intraoperative complication rates (2.1% vs. 21%) and vertebral artery injury (2.1% vs. 13.1%).
• Both techniques improved neck pain, C2-radiculopathy, and hand function, with a trend towards better results in the Harms group.

Conclusions:

• Both Magerl and Harms techniques are effective for C1-C2 stabilization.
• The Harms technique demonstrates a superior safety profile with fewer complications and more robust long-term fixation.
• While fusion rates were similar, the Harms technique resulted in a lower C1-C2 range of motion.