Development and Validation of a Modified Ovine Model for Anterior Cervical Discectomy and Fusion (ACDF) Studies

Background Sheep cervical spines resemble human spines in size and mechanics. However, anatomical differences prevent unmodified use of human fusion devices. Endplate preparation variations may affect results. To develop and validate a low-cost, accurate, and simple ovine cervical spine model system for intervertebral fusion mimicking the human spine. Methods We obtained CT scans from 10 male sheep cervical specimens. Measurements included intervertebral space height; anterior-posterior diameter; left-right diameter; maximum cage depth. We designed an anatomically matched fusion device. Two male sheep underwent ACDF using this cage. Postoperative imaging assessed cage position. After 10 weeks, we explanted fused segments. Bone integration was assessed via micro-CT and histological analysis. Results We successfully fabricated the model system using metal 3D printing. The system underwent size, shape, and mechanical validation. No device displacement occurred postoperatively. Micro-CT and histology demonstrated significant bone ingrowth, with stable osseointegration confirmed. Conclusion. This stable, anatomically accurate sheep model provides a reliable system for intervertebral fusion experiments. It serves as a valuable reference for large animal studies.