Surface structural damage study in cortical bone due to medical drilling.

Area of Science:

• Biomechanics
• Biomedical Engineering
• Optical Metrology

Background:

• Bone fractures require fixation, often involving surgical screws that can lead to bone volume loss and structural modification.
• Understanding the mechanical effects of drilling on bone is crucial for optimizing internal fixation procedures.

Purpose of the Study:

• To analyze the surface displacement variations in porcine femoral bones subjected to drilling and compression.
• To investigate the relationship between compression load, bone volume loss, and drilling parameters.

Main Methods:

• Digital holographic interferometry was employed to record surface displacement maps of post-mortem porcine femurs.
• Bones were subjected to varying compression loads (30-400 lbs) with and without cortical drillings.
• High-speed CMOS cameras captured interferometric holograms for detailed analysis.

Main Results:

• Pseudo 3D mesh displacement maps visualized bone surface behavior under physiological and supra-physiological loads.
• A direct correlation was observed between compression load and bone volume loss resulting from drilling.
• The study demonstrated significant microstructural modifications due to drilling and applied forces.

Conclusions:

• Digital holographic interferometry is a viable, high-resolution technique for studying bone mechanics.
• The findings provide insights into factors influencing surgical screw loosening in orthopedic procedures.
• This method can aid in developing strategies to enhance the stability of internal bone fixation.