The Use of Biomechanical Workflows in the Development of Orthopaedic Devices

Orthopaedic device performance is often evaluated using standard methods, but musculoskeletal models can provide additional insights. This study investigates the implementation of biomechanical frameworks to enhance our understanding of orthopaedic device performance. One example presented is stress shielding in a shoulder implant construct. By incorporating realistic material properties and activities of daily living, models were developed to understand device performance under physiological conditions. A shoulder implant construct finite element model was created to evaluate stress shielding. A mean bone was developed from subject-specific data, which involved calculating the statistical bone shape and volumetric intensity data derived from CT scans. These volumetric data were converted to Young's modulus to represent bone material properties. A shoulder implant was added to the bone, and loads from six different activities of daily living were applied to the construct. Stress shielding was evaluated for individual activities, as well as for the aggregate of all activities. The analysis showed the effects of stress shielding under different musculoskeletal loads. Differences in stress shielding resulted from the different directions and magnitudes of the loading. The combined effect of all activities was also evaluated, and showed that the area with the highest stress shielding was on the proximal end of the construct. This framework shows the potential for biomechanical models in evaluating orthopaedic devices. The findings highlight the importance of considering the sources of variability within the system, and the power of modelling to understand their effects.