Functional assessment of upper extremity function for the development of shoulder and elbow prostheses.
1999 - 99 / 2003
Introduction: There is a large difference between patients in the regained functionality after surgery. Discriminating factors between a successful and failing intervention are unknown. A thorough evaluation of existing prostheses and normal shoulders might indicate critical success factors. Therefore, also the loading conditions and range of motion must be assessed. These data must be combined into an interactive tool for surgeons to computerised experimentation and prediction of the functionality of the endoprosthesis. Goals: To improve the functionality of the shoulder and elbow prosthesis: 1. Functional analysis (motion and force recordings) of the extremity with existing endoprostheses and the contra-lateral arm, with special attention to morphological and design factors. 2. Sensitivity analysis of these factors using a musculoskeletal model of the upper extremity. 3. Assessment of range of motion and muscle strength required for important Activities of Daily Living (ADL), data essential for a functionality analysis of existing endoprosthesis 4. Specifications of newly designed endoprosthesis and placement techniques to improve the functionality. Methods: In the past decade, a detailed three-dimensional musculoskeletal model of the shoulder and elbow has been developed. This model can be used to evaluate the actual performance of the arm, but also to predict the effect of changes (sensitivity) of the endoprosthesis design and surgical technique. Range of motion and loads during ADL will be measured with an electromagnetic position recording device and force transducers, in order to obtain requirements for a design. Based on the shoulder and elbow model, the computer-aided support system will be used which allows the surgeon to interactively apply current endoprosthesis types or new designs, by changing design parameters and placement, and by displaying outcome variables of interest.