A Safe, Effective, and Economical Protocol for Rabbit Vertebral Screw Insertion.

Posterior lumbar screw fixation is the most common surgical method for lumbar disc herniation, but patients often face multiple complications postoperatively. The occurrence of screw track loosening can lead to fusion failure and even life-threatening screw track extrusion. However, there is currently a lack of animal models specifically targeting changes in the screw track following lumbar screw fixation. This study developed a vertebral screw insertion method based on New Zealand white rabbits, designed to minimize the risk of postoperative screw penetration into the spinal canal, thus avoiding spinal cord injury. In this protocol, the intersection point of the horizontal line from the upper edge of the transverse process and the junction of the pedicle is recommended as the entry point. The insertion angle should be approximately 45°-55° outward and 20°-40° downward. Additionally, based on screw placement under direct vision and the use of commercial instruments,this method is simpler and more cost-effective compared to existing large animal modeling techniques. It provides an animal model for subsequent basic research on screw track loosening and the microenvironment surrounding the screw track.