Posterior C2 Fixation Using Trans-C2 Inferior Articular Process Screws: A Case Series and Technical Note

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Spinal Surgery

Background:

• Upper cervical fixation is crucial for spinal stability.
• C2 pedicle screw insertion carries a risk of vertebral artery injury, especially in patients with craniovertebral junction anomalies.

Purpose of the Study:

• To describe and evaluate the efficacy of a novel trans-C2 inferior articular process screw (C2IAPS) insertion technique.
• To provide a safe alternative for rigid C2 fixation in patients ineligible for C2 pedicle screw fixation.

Main Methods:

• Retrospective review of 19 patients undergoing posterior atlantoaxial fixation using C2IAPS and C1 lateral mass screws.
• Assessment of screw placement safety, Japanese Orthopaedic Association (JOA) scores, and bony fusion rates via postoperative imaging.

Main Results:

• 22 C2IAPSs were successfully implanted with a high safety profile; only 2 screws showed minor intrusion into the intervertebral foramen.
• Significant improvement in JOA scores from 11.8 preoperatively to 15.3 postoperatively.
• Achieved a 100% bony fusion rate.

Conclusions:

• C2IAPS fixation is a viable and safe alternative for upper cervical fixation, particularly for patients with craniovertebral junction anomalies or contraindications to C2 pedicle screw fixation.
• This technique provides rigid fixation and promotes successful bony fusion.