Page 557 - IJB-10-2

International Journal of Bioprinting OLS design for distal femur osseointegration

Table 1. Material properties and number of elements/nodes for each model used in the finite element analysis
Material Elastic modulus Poisson’s ratio Reference
(GPa)
Cortical bone 17 0.3 38,39,40
Cancellous bone 0.52 0.29 39,41
Reconstruction plate (Ti6Al4V) 110 0.37 42,43
and screws
Implant body
Number of nodes/elements Elements Nodes
Cortical bone 185,123 310,457
Cancellous bone 397,580 581,592
Reconstruction plate 216,784 330,754
Screws 100,720 108,200
Implant (with lattice) 138,394 205,286

using metal 3D printing (AM250, Renishaw plc, Woton- utilized as the test subject for biomechanical testing, with a
under-Edge, Gloucestershire, UK). The process parameters sample size of n = 3.
included layer thickness of 30 μm, laser power of 100 W, laser In the biomechanical testing process, the test
exposure time of 60 μs, laser focus of 75 μm, point distance model was secured within a universal testing machine
of 75 μm, and hatch distance of 20 μm. The femur model (HT-2402 Universal material testing machine, Hung
was fabricated using FDM polymer 3D printing (Fortus Ta Instrument Co., Ltd., Taichung, Taiwan). A strain
250MC, Stratasys Ltd., Reḥovot, Israel). Subsequently, gauge was attached near the interface between the
femoral head and the implant. A downward force was
the implants (OLS and NLS implants) and bone cement then applied to the femoral head at a controlled loading
were attached to the femur model using a reconstruction speed of 2 mm/min, and the strain gauge’s value
42
plate and screws, respectively. This assembled model was was recorded when the loading reached 2800 N. This

Figure 3. Demonstration of the mesh model for the finite element analysis.

Volume 10 Issue 2 (2024) 549 doi: 10.36922/ijb.2590