Comparative Analysis of Bone Ingrowth in 3D-Printed Titanium Lattice Structures with Different Patterns

Area of Science:

• Biomaterials Engineering
• Orthopedic Surgery
• Additive Manufacturing

Background:

• Orthopedic implants require osseointegration for successful integration.
• Lattice structures in implants can enhance bone ingrowth.
• Optimizing lattice design is crucial for improving implant performance.

Purpose of the Study:

• To investigate the effect of six different lattice shapes on bone ingrowth in orthopedic implants.
• To compare the bone ingrowth efficiency of gyroid, cube, cylinder, tetrahedron, double pyramid, and Voronoi lattice structures.
• To develop and validate a new image processing algorithm for quantifying bone ingrowth.

Main Methods:

• Direct metal laser sintering (DMLS) 3D printing of Ti6Al4V alloy lattice implants.
• Surgical implantation into ovine femoral condyles, with analysis at 8 and 12 weeks.
• Mechanical compression testing, histological analysis, and a novel image processing algorithm for bone ingrowth quantification.

Main Results:

• Gyroid, double pyramid, and cube lattice shapes demonstrated the highest bone ingrowth rates.
• The ranking of these top three shapes remained consistent at both 8 and 12 weeks post-implantation.
• The developed image processing algorithm accurately quantified bone ingrowth and was supported by histological findings.

Conclusions:

• Gyroid, double pyramid, and cube lattice designs are highly effective for promoting bone ingrowth in orthopedic implants.
• These lattice structures offer comparable or superior bone ingrowth to previously studied designs like the cube.
• The new image processing technique provides a reliable method for evaluating bone ingrowth in lattice implants.