Page 463 - IJB-9-5

International Journal of Bioprinting 3D-printed oblique lumbar interbody cage

Figure 9. von Mises stress distributions for the intact, CA, CES, and CLS models under flexion, extension, bending, and torsion.

this cage profile to improve overall system stability after 67%/73%/99%/97% and 75%/68%/94%/95%, respectively,
surgery . with a relative overall decrease of approximately 84% and
[24]
83% in ROM, respectively. The CES model demonstrated
Metal 3D printing techniques are well-established
for building complicated 3D medical implants and have better stability among all implantations regardless of load
condition. However, the decrease in ROM of the three
great potential to solve the problems of creating a porous fixation methods in terms of bending and rotation was
titanium body [11,12,24] . Many studies have indicated that greater than that of flexion and extension, consistent with
titanium implants manufactured via 3D printing with a a previous study . Furthermore, the CES model was also
[15]
porous design can enhance bone stability through enough comparable to the lateral enhanced fixation of CLS, which
bone ingrowth [11,12,24] . Therefore, the hollow part within the can provide higher stability especially in flexion.
cage and exterior walls of the cage without the supporting
solid structure was designed as grooves according to the Excessive stress on the endplate may result in
suggestion of the WTO analysis. This was filled with YM destruction or fracture of the endplate. Thus, it is necessary
lattice, which has good performance in terms of bone to confirm whether the vertebral cage system induces
ingrowth capability and bonded strength between the unfavorable stress on the endplate during implantation.
implant and bone. This reduces the stress-shielding effect On FE analysis, we found that contact areas at the anterior/
while increasing bone growth and improving overall posterior edges between the cage and endplate during
stability. CES implantation can effectively reduce stress values and
Lumbar interbody fusion surgery aims to increase the distribution to decrease endplate damage and the risk of
stability (i.e., decrease the ROM) between two vertebral cage subsidence especially during extension. This suggests
bodies is the main goal. The results of FE analysis showed that our OLIF cage with the embedded fixation screws can
that CA implantation reduced the ROM by 62%, 52%, more effectively transmit cage force to the endplate than
93%, and 96% under flexion, extension, lateral bending, that with lateral plate fixation. This result was in line with
and rotation, respectively, compared to the intact model. the previous ROM results.
ROM decreased by an average of about 75%. The relative Complex contours and the internal lattice design
decreased percentages of the CES and CLS implantations of the OLIF cage only can be fabricated by 3D printing
under the aforementioned four load conditions were rather than traditional mechanical cutting. Previous

Volume 9 Issue 5 (2023) 455 https://doi.org/10.18063/ijb.772