Biomechanics and Motion Analysis

Effectiveness of Total Knee and Total Hip Arthroplasty

Principal Investigator: Daniel J. Berry, M.D.
Project Coordinator: Alex Hooke — hooke.alexander@mayo.edu

The effectiveness of total knee arthroplasty and total hip arthroplasty in relieving pain and improving function is undisputed. Standardized instruments have been developed in order to assess the severity of symptoms and evaluate the outcomes of treatment. A major component of these scoring systems is range of motion (ROM). This measure is widely used because it is an easily understood, direct measure of the joint’s condition. Despite the intuitive connection between joint flexibility and operative success, it remains to be shown how measured ROM influences the most important outcome: a patient’s ability to use the prosthetic joint in activities of daily living (ADL). With substantial resources being devoted to improve the implant design to better fit the patients’ ROM needs during ADL, improving knowledge about patient ROM during the ADL is an important concern. ROM after total hip or knee arthroplasty is measured by the physician during the patient pre-or post-operative evaluation using simple tools with limited reliability and repeatability. These tools are not applicable to measure ROM during patient ADL. In addition, there is little data on hip and knee kinematics during ADL, particularly outside of the laboratory setting.

New tools such as body fixed inertial sensors (gyroscopes, accelerometers and magnetometers) are now available.  All the segments of the lower limb can be analyzed at the same time and unlike indoor standardized measurements, these ambulatory systems can be used anywhere, in any condition.  Therefore, it is now possible to collect objective and reliable 3-D data on joint motions required for ADL activities from different samples of the population under real life conditions.  This study takes data collection outside of the lab setting to get a quantitative perspective on how knee and hip arthroscopy effects patients' ROM on a daily basis.