Measurement of the Kinematics of Normal and ACL Deficient Knees Using Fluoroscopy with Computer Bone Models

• Main Authors: Tzong-Yuan Tsai, 蔡宗遠
• Other Authors: 呂東武
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/35586101620737323531

碩士 === 國立臺灣大學 === 醫學工程學研究所 === 92 === Knowledge of the kinematics of the knee is essential for the understanding of its function. To the best knowledge of the author, no study has investigated the in vivo kinematics of the knee using non-invasive method. The purposes of the study were to develop a non-invasive method for the determination of three-dimensional (3D) dynamic skeletal motions in vivo using fluoroscopy and to apply this method to the study of the knee kinematics during isolated knee flexion/extension under loaded and unloaded conditions in normal and anterior cruciate ligament deficient (ACLD) subjects. The new method involves the match of two-dimensional (2D) fluoroscopic images of the knee during motion with projections of the computer knee models reconstructed from serial computer tomography images. The 3D knee position that produced best-matched projection with the fluoroscopic image was then taken as the special position of the tested knee. Computer simulations were performed and results show an estimate accuracy of 1 mm and 0.5 degrees. A rotating stage was constructed induce to control accurately the motion of a cadaver calcaneus for validation of the study. The result of our validation experiment showed that the accuracy is within 0.8 degrees and 1.9 mm for orientation and translation respectively. The results of the in vivo studies showed that screw home mechanism existed and movement of unloaded knee can be described by an envelope of active flexion. In normal subjects, patterns of both unloaded and loaded active motion were similar to those of reported in the literature. However, the variation of the active motion in loaded condition was bigger than that in unloaded condition which may be due to the variation of muscle control to counteract the external forces. In ACLD subjects, either unloaded or loaded active motions at knee were different from those in the normal ones. The results indicated that the ACL played an important role in the control of the stability and mobility of normal knee motions.