Abstrakt

An Intra-Bone Axial Load Transducer: Development and Validation in an In-Vitro Radius Model

Nikolas K Knowles, Michael Gladwell, Louis M Ferreira

A method to accurately measure forces through the radius is necessary due to the complex loading of the elbow. It was hypothesized that a custom axial load measurement device may allow for the accurate quantification of these unknown forces. This work reports on the design and validation of an axial load transducer interposed in the diaphysis of a long bone that maintains the native articular location. The performance of the device in quantifying axial loads is evaluated in an in-vitro isolated proximal radius model. The model was validated by statically applying linearly increasing proximal radius loads on a servo-hydraulic testing frame mounted using a pivot support to nullify reaction moments. The direction of net applied load was varied to simulate multiple forearm positions and flexion/extension angles (10, 20, 30 and 40 degrees). There was no significant difference between axial transducer load and expected load (p<0.001). Axial transducer loads were in close agreement with expected loads in all forearm positions for forearm angles up to 30 degrees. The results validated the efficacy of the device in measuring osseous loading while maintaining the native articular location.