Design, Construction, and Validation of a Cadaver Knee Motion Testing Device

The knee joint is complex. Surgical procedures such as ACL reconstruction and total knee arthroplasty (TKA) are commonly used to alleviate pain and restore function in knees that suffer from injury or disease. These surgeries affect the kinematics of the joint. It is important to understand exactly how surgical procedures affect knee motion in order to be able to better restore normal joint function post-operatively. Knee kinematics are best investigated in actual knees; however, since it is unethical to simulate surgery in living subjects, there is a need to utilize cadaver specimens. Previous research studies have used various testing devices to study the knee, including robotic systems, weight and pulley systems, and systems involving pneumatic actuators. The limitations of existing devices have motivated the development of a new device. The goal of this project was to design, construct, and validate a cadaver knee motion testing device using passive motion for the purpose of understanding how surgical procedures affect knee kinematics. I used my knowledge of kinematics, machine design, and biomechanics for the design of the mechanism. The construction of the entire device was completed in the Scott Lab student machine shop. The device is controlled through the LabVIEW software using an open-loop control, with the goal of eventually implementing closed-loop control with the use of a potentiometer. The effects of a variety of procedures and surgical parameters on knee motion will be obtained using the device and will be beneficial in motivating possible future improvements in prosthetic design and surgical technique.