Page 396 - IJB-10-4

International Journal of Bioprinting Design of biofixed metamaterial bone plates and fillers

from uneven load distribution), resulting in loosening and plate to maintain appropriate contact and compression
fractures. In this regard, personalized bone plates can be with the fracture fragments according to the fracture
used to effectively treat the different types of bone injuries condition after fixation, thereby improving the success
and accommodate the distinct bone structures of each rate of fracture and bone defect surgeries. Kunjin et al.
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patient. Personalized bone plates have been widely used streamlined and improved the efficiency of bone plate
for biofixation due to their excellent compatibility, low designs by initially templating an average skeletal model
weight, uniform distribution of mechanical load, and good and subsequently selecting regions of interest and defining
biocompatibility. However, these bone plates are difficult semantic parameters when reconstructing a bone plate.
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to produce. Vijayavenkataraman et al. proposed a novel bone plate
The development of three-dimensional (3D) printing design method of incorporating an auxetic structure to
technology allows the production of personalized bone overcome the stress-shielding effect and the misalignment
implants for biofixation. 3D printing uses specialized of the occlusion caused by dislocation at the fracture site
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data processing software to slice and layer 3D models into during healing. Liu et al. 3D printed personalized Ta-
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sectional data, which is then imported into a 3D printer coated porous Ti6Al4V (PTi) bone plates with a modulus
to construct the bone implants layerwise. Among the of elasticity similar to cortical bone and no stress shielding.
4,5
3D printing techniques, selective laser melting (SLM), Despite the advancement in the design and production
characterized by laser melting metal powder materials, is of novel bone plates, the lack of studies on metamaterial
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of particular interest and was used in the present study. bone plate designs based on 3D printing technology
3D printing can be used to create single-piece warrants further research, particularly in the design of
structures, small batches of constructs, complex a curved porous structure with a larger surface area-to-
geometrical structures, and even dense constructs. volume ratio, the transformation mechanism of a solid
Zhang et al. 3D printed a bone plate based on topological bone plate to a curved porous bone plate, the transition
optimization and finite element modeling to improve mechanism from a porous structure to a solid structure,
the stress-shielding effect caused by the excessive elastic and conformal modulus regulation of bone plates.
modulus of the metal bone plate during the fracture This study mainly focused on porous curved
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healing process. Wang et al. divided the bone plate into structures, owing to their superior biocompatibility.
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special and regular components and constructed models Herein, we investigated the design and production process
for each component. The boundary and surface features of of personalized metamaterial curved bone plates for
the components were then input into a database for easy biofixation applications.
retrieval when designing personalized bone plates. Sun et
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al. proposed a topological optimization design for surface 2. Methods
gradient porous structures to regulate the functional
characteristics of porous single-cell configurations in 2.1. Preparation of the filler material
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multi-porous structures. Wei et al. reported that the The design and relevant performance testing of porous
combination of 3D printing technology and personalized structures as fillers were conducted based on the ISO13314
bone plate internal fixation in the treatment of severe tibial standard. The materials were selected based on the
18-20
plateau fractures could shorten the operation time, reduce following biocompatibility and production parameters :
surgical trauma, and facilitate early recovery. Similarly, (i) Biocompatibility: pore size: 100–800 µm; porosity:
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Wang et al. reported that the application of 3D printing- 50–90%; surface area-to-volume ratio: high
assisted internal fixation in treating complex tibial plateau (ii) Production: sharp corners and thin walls > spot
fractures could reduce the operation time, intraoperative diameter; minimum aperture > spot diameter
blood loss, and fluoroscopy time based on effective
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articular surface reduction. Zhang et al. investigated the The selected porous structures were diamond, gyroid,
clinical characteristics of residual femoral shaft fractures in Lidinoid, and Split P. The porous structures were then
children with the sequelae of poliomyelitis and the clinical digitally created using the parametric modeling software
effects of 3D printing-simulated surgery combined with Rhinoceros, and the structural parameters (e.g., porosity,
customized steel plate treatment. Pobloth et al. designed average pore size, and surface area-to-volume ratio) of each
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honeycomb-like 3D titanium alloy mesh scaffolds with porous structure were adjusted with the input parameters
different stiffness that could effectively reduce the stress- (i.e., unit size, number of units, and unit type). The porous
shielding effect and promote the healing and regeneration structures were then processed in a 3D software to model
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of large animal bones. Huri et al. proposed an adjustable the porous structure with a width or diameter at least ten
bone plate setting method, which allows the bone times the pore size (W ≥ 10d or D ≥ 10d ) and a height
2
0
2
0
Volume 10 Issue 4 (2024) 388 doi: 10.36922/ijb.2388