RESPONSE OF LIVING BONE TO CONTROLLED TIME-VARYING LOADING - METHOD AND PRELIMINARY-RESULTS

This paper describes a method and equipment for applying controlled sinusoidally-varying axial compressive loading to a typical animal long bone - the ovine metacarpus. The loading is generated hydraulically and applied to the bone through stainless steel bone-pins surgically inserted in the metaphyses. For the ovine metacarpus, the mid-diaphyseal cross-section is well removed from the sites of surgical trauma and from the points of load application. Preliminary results show that the bones responded by adaptive remodelling in the mid-diaphyseal region. The maximum increase in cross-sectional area during a 28-day test period was approximately 17% when the nominal compressive stress was 8.8 MPa. Although a uniform stress field on the mid-diaphyseal region is theoretically possible, it has been found that significant stress non-uniformity may occur due to slight eccentricity of loading. © 1979.