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

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 (Kp) of the test blocks in different groups of Sawbone. The larger the Kp 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 (Kp value) of the test block for the 3D-printed titanium cage in the static subsidence test was 270 N/mm, while the Kp 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.