Two New Innovative Rehabilitation Procedures Based on 3D Joint Kinematics / The Japanese Journal of Rehabilitation Medicine

ABSTRACT

One of the purposes of rehabilitation is patient joint recovery, which consists of providing both pain relief and normal function. A functional evaluation is essential to estimate the clinical results, and this is accomplished by analyzing the joint kinematics. Thousands of cadaveric studies were already reported but these may differ from the <i>in vivo</i> results because they lack ligamentous or muscular effects. Therefore, the development of an <i>in vivo</i> 3D kinematic analysis system was needed for the proper diagnosis of pathological movement and the evaluation of postoperative function. Accordingly, two such systems were developed at our institute. The first system uses 3D CT or MRI and it is suitable for joint movement analysis. The targeted joint is placed in serial positions of the motion plane to evaluate the 3D kinematics of the motion, and images are obtained in each position. The data are saved and transmitted to a computer workstation. Kinematic variables are measured automatically. Animations of the joint movement are then created from the calculated motions. The second system uses a radiographic image intensifier. It can evaluate real-time 3D dynamic motion of metal implants and it is available to evaluate joint kinematics after arthroplasty. The 3D pose-estimation technique is built on a 2D-3D registration algorithm, which determines the spatial pose for each component from the implant contours and computer-assisted design models of the implant. Sequential fluoroscopic images are then taken in the sagittal plane.