In vitro method to quantify and visualize mechanical wear in human meniscus subjected to joint loading

Area of Science:

• Orthopedics
• Biomechanical Engineering
• Medical Imaging

Background:

• Repetitive joint loading causes mechanical wear in soft connective tissues, a key factor in degenerative joint disease.
• Accurate methods for quantifying wear in joint structures, particularly the meniscus, are essential for understanding and treating joint degeneration.

Purpose of the Study:

• To evaluate the accuracy of a structured light 3D optical scanning system and modeling software for quantifying and visualizing volume loss in human menisci under in vitro joint loading.
• To establish a novel method for accurately characterizing volumetric changes in the meniscus due to mechanical wear.

Main Methods:

• Utilized 3D printed meniscus replicas with known wear volumes to determine the accuracy of the 3D optical scanning system.
• Applied the validated imaging method to measure in vitro wear of whole human menisci subjected to one million cycles of controlled joint loading.
• Generated colorimetric maps to visualize linear wear depth and identify regions of high wear and deformation.

Main Results:

• The 3D optical scanning method demonstrated a mean accuracy of approximately 13 mm³, with a mean error less than 7% for measuring volumetric changes of 0.2 cm³.
• Medial and lateral menisci exhibited steady-state volumetric reductions of 0.72 cm³ and 0.34 cm³ per million cycles, respectively.
• High wear and deformation were observed in the posterior regions of both medial and lateral menisci.

Conclusions:

• A novel, accurate method using 3D optical scanning has been developed to characterize volume loss in the whole meniscus subjected to in vitro joint loading.
• This 3D scanning technique provides a valuable new tool for researchers studying mechanical wear and joint degeneration in menisci and other soft connective tissues.