Analysis of the anti-subsidence mechanical properties of novel 3D-printed titanium cages compared to conventional titanium cages.

Abstract

Background: Titanium cage subsidence remains a common complication following anterior cervical corpectomy and fusion. 3D printing technology can optimize titanium cages, including high geometric matching and unique porous graded structures, providing a better option for improving titanium cage subsidence. This study aims to evaluate the mechanical properties of 3D-printed titanium cages and compare them with those of conventional titanium cages, providing preclinical data for future clinical trials.

Methods: The samples were divided into a 3D-printed titanium cage group and a conventional titanium cage group, with 5 samples in each group. A static compression test was conducted using the American Society for Testing and Materials (ASTM) F2077-14 standard to evaluate the stiffness of the titanium cages. A static subsidence test was conducted using the ASTM F2267-04 standard to evaluate the stiffness (K_p) of the test blocks in different groups of Sawbone. The larger the K_p value, the smaller the tendency of titanium cage subsidence.

Results: In the static compression test, the stiffness of the 3D-printed titanium cage and the conventional titanium cage were (6562.60 ± 390.72) N/mm and (10252.40 ± 704.07) N/mm, respectively, with a statistically significant difference (P < 0.05). In the static subsidence test, the stiffness of the 3D-printed titanium cage system and the conventional titanium cage system were (258.60 ± 7.99) N/mm and (221.00 ± 20.36) N/mm, respectively, with a statistically significant difference (P < 0.05). Additionally, the stiffness (K_p value) of the test block for the 3D-printed titanium cage in the static subsidence test was 270 N/mm, while the K_p value of the test block in the conventional titanium cage static subsidence test was 226 N/mm, indicating a 19.5% increase in anti-subsidence capability.

Conclusion: The optimized 3D-printed titanium cage, featuring anatomical conformity and a 70% porous structure, demonstrates 19.5% improved anti-subsidence performance compared to conventional designs, addressing limitations in prior 3D-printed solutions, providing a promising and feasible solution for reducing the subsidence of titanium cages.