Direct visualization and quantification of bone growth into porous titanium implants using micro computed tomography.

Area of Science:

• Biomaterials Science
• Orthopaedic Research
• Medical Imaging

Background:

• Porous metals are vital for integrating orthopaedic implants with bone.
• Quantifying bone response to implants traditionally involves laborious histology.
• Micro-computed tomography (μCT) offers a potential 3D imaging solution.

Purpose of the Study:

• To evaluate and compare micro-computed tomography (μCT) with histology for quantifying bone ingrowth in porous titanium implants.
• To assess the effectiveness of μCT in measuring bone volume and implant porosity.

Main Methods:

• Cylindrical porous titanium implants were inserted into rabbit femora and tibiae.
• Bone ingrowth was analyzed after 6 weeks using μCT, light microscopy, and backscattered electron microscopy.
• Quantification involved measuring bone volume, implant porosity, and pore interconnections.

Main Results:

• μCT-derived bone volume and implant porosity closely correlated with traditional histology findings.
• Bone ingrowth was observed in pores with interconnections larger than 9.4 μm.
• Pore interconnection size above 28.2 μm had minimal effect on bone density within titanium foam.

Conclusions:

• μCT is a suitable and effective technique for quantifying bone ingrowth in porous titanium implants.
• This 3D imaging approach provides a reliable and potentially more efficient alternative to conventional histology.
• Findings highlight the importance of pore interconnection size for successful bone integration.