Minimum 5-year Follow-up Results for Occipitocervical Fusion Using the Screw-Rod System in Craniocervical Instability

Area of Science:

• Neurosurgery and Orthopedic Surgery
• Spinal Fusion Techniques
• Biomechanical Engineering in Implants

Background:

• Long-term outcomes of occipitocervical (OC) fusion using pedicle screws and rods are sparsely documented.
• Evaluating the durability and efficacy of current OC fusion methods is crucial for patient care.

Purpose of the Study:

• To assess the clinical results of posterior occipitocervical (OC) fusion utilizing pedicle screws and rods.
• To analyze patient outcomes over a minimum follow-up period of five years.

Main Methods:

• Retrospective analysis of 27 patients undergoing posterior OC fusion with pedicle screws and rods.
• Preoperative and postoperative neurological function assessed using the Modified McCormick scale and Japanese Orthopaedic Association (JOA) scores.
• Fusion assessment via direct evidence (bony trabeculae) and indirect evidence on radiographs and CT scans.

Main Results:

• A mean follow-up of 7.2 years showed significant improvement in JOA scores (42.0% recovery rate).
• 66.7% of patients experienced at least a one-grade improvement on the Modified McCormick scale, with no neurological deterioration.
• Implant-related complications occurred in 29.6% of patients, including screw loosening, rod/screw breakage, and pullout, with an average onset of 31.2 months post-surgery.

Conclusions:

• Occipitocervical fusion with pedicle screws and rods can yield positive long-term functional outcomes.
• Strategies such as adequate bone grafting, thorough decortication, and utilization of high-stiffness rods are recommended.
• Considering ultra-high molecular weight polyethylene tape for fixation or reinforcement may mitigate implant failure.