An in vivo subject-specific 3D functional knee joint model using combined MR imaging

Area of Science:

• Biomechanics
• Medical Imaging
• Orthopedics

Background:

• Understanding knee joint kinematics is crucial for diagnosing and treating knee derangements.
• Current methods for assessing knee function in vivo under load have limitations.

Purpose of the Study:

• To quantitatively characterize knee joint function in vivo using subject-specific models derived from magnetic resonance (MR) data.
• To better understand 3D knee joint kinematic function under body-weight-bearing conditions.

Main Methods:

• Six healthy volunteers underwent MR imaging during quasi-squatting motion.
• Subject-specific 3D knee models were created using semi-automatic segmentation and bi-rigid registration.
• Tibio-femoral articulation contact mechanisms were analyzed to extract and plot contact point trajectories.

Main Results:

• 3D models revealed relative rotation and gliding between tibia and femur during flexion.
• Contact points exhibited reduced movement between 30° and 100° flexion on both tibial plateaux.
• Four volunteers showed less contact point movement on the medial tibial plateau compared to the lateral.

Conclusions:

• The developed subject-specific model effectively characterizes knee joint kinematic function.
• This approach provides a quantitative method for describing knee joint surface kinematics.
• The findings may aid in understanding normal knee function and joint derangements.