## 4 Discussion
At 83% porosity, the composite configuration achieved a peak equivalent stress of 20.69 MPa, representing reductions of 22.91% and 5.52% relative to rectangular and circular porous counterparts, respectively. From the displacement cloud map, it can be seen that the displacement of all implant structures is basically in a layered state, indicating that the main displacement trend is dominated by the direction of force loading, and there are not too many slip trends that are different from the direction of force loading. With the continuous increase in porosity, the maximum displacement values on tibial implants of different structures all increase. This is due to the increase in porosity, which reduces the matrix material used to support the implant and leads to a decrease in its ability to resist deformation. The tibial implant with a composite pore structure exhibited smaller micro movements, indicating its strong anti-slip ability. The edge displacement of all models in this article did not exceed the maximum allowable movement for bone healing. The results of the biomechanical experiments demonstrate that the maximum tibial displacement exhibits an increasing trend as the porosity of the implanted tibial inserts increases, indicating reduced overall implant stiffness at higher porosity levels. When porosity increased from 53% to 83%, tibiae implanted with composite, square, and circular pore structures showed displacement increments of 11.98%, 6.91%, and 4.44%, respectively. Notably, while composite pore implants demonstrated the steepest displacement growth rate, they consistently exhibited the lowest absolute displacement values across all porosity levels, reflecting superior mechanical stability during porosity escalation. Distinct performance variations emerged among pore architectures under equivalent porosity conditions. At 53% porosity, composite pore implants achieved 1.67 mm displacement, representing 11.17% and 7.22% reductions compared to square (1.88 mm) and circular (1.80 mm) pore configurations. This advantage intensified at 83% porosity, where composite pore implants recorded 1.87 mm displacement, outperforming square (2.01 mm) and circular (1.88 mm) designs by 6.97% and 0.53%, respectively. It is worth noting that circular pore implants demonstrated secondary performance to composite structures at lower porosities (53-63%), but exhibited accelerated displacement growth when porosity exceeded 73%. Square pore configurations consistently produced the highest displacements in all biomechanical tests, peaking at 2.01 mm (83% porosity)--7.49% greater than their composite counterparts. Comprehensive analysis confirms that composite pore implants exhibit enhanced mechanical stability through their hybrid pore architecture, which significantly improves load-bearing capacity while maintaining osteointegration-essential porous spaces. Across the full 53-83% porosity spectrum, these implants achieved minimal postoperative tibial displacements(1.67-1.87 mm), outperforming conventional single-pore designs by 7.0-12.0%. These findings substantiate the composite structure's exceptional balance between high porosity requirements and mechanical performance preservation.