Evaluating the function of total joint replacements

The primary function of hip and knee joints is to permit movement. The pathology of arthritic diseases leads to loss of articular surface anatomy and deformity which will impede motion. Consequently, one of the primary goals of total joint replacement is to restore mobility. The assessment of implants in the research and development phase includes the use of computer models, joint simulators and clinical trials. Clinical evaluation assesses motion, the ability of a patient to perform certain activities and the potential use of assistive devices. These assessments encompass patient examination and measurement of motion about the joint, instrumented tools (accelerometers, gait analysis), questionnaires (self-report, interview-based), and performance-based evaluations. In order to fully appreciate the functional outcome of a total joint implant, more than one type of assessment is required.