J Vet Sci.  2024 Jan;25(1):e2. 10.4142/jvs.23241.

Cervical spine reconstruction after total vertebrectomy using customized three-dimensional-printed implants in dogs

• Jeon JW
• Kang KW
• Kim WK
• Yang S
• Kang BJ

• KMID: 2553229
• DOI: http://doi.org/10.4142/jvs.23241

Abstract

Background
Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery.
Objective
To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy.
Methods
Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3–C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/ polymethylmethacrylate after testing in Group A).
Results
All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3– C7 compared with intact spines (p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4–C6, but only group B showed significance (p = 0.005, and 0.027).
Conclusion
Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability.

Keyword

Cervical spine; reconstructive surgery; 3D printing; mechanical testing; dogs