Contact Characteristics during Different High Flexion Activities of the Knee

摘要

Squatting, kneeling and sitting cross-legged activities require a very high range of motion of the knee joint. Many studies have focused on the kinematics of these activities using motion capture systems or fluoroscopy images with reconstructed computer models. These methods do not report the contact characteristics in high flexion activities. Although magnetic resonance images could easy to calculate the contact area, the magnetic resonance scan requires many times and is not suitable for functional activity. The purpose of this study was to build a procedure to investigate the contact characteristics for different high flexion activities based on bi-plane orthogonal X-ray images with computational models reconstructed by computer tomographic and magnetic resonance images. Computational bone models, including the femur, tibia, fibula and patella, were reconstructed by computer tomographic images. Computational cartilage models, including femur, tibia and patella, were reconstructed by magnetic resonance images. We used the sensitivity test to test the mapping accuracy and the error value is less than 5% so that the mapping is reasonable. There is no contact in standing in patel-lofemoral joint. The contact location in patella is moving upward from the distal patella with knee flexion. When squatting, the contact location separates to two parts. The contact in kneeling and sitting cross-legged also presents the same result. The contact area in patellofemoral joint is increasing with flexion, but decreasing to 849.94mm~2 in squatting. The contact area in kneeling and sitting cross-legged is 388.63mm~2 and 815.16 mm~2, respectively.