Structural properties of a new design of composite replicate femurs and tibias

Abstract

The purpose of this study was to compare the structural properties of a new vs. established design of composite replicate femurs and tibias. The new design has a cortical bone analog consisting of short-glass-fiber-reinforced (SGFR) epoxy, rather than the fiberglass-fabric-reinforced (FFR) epoxy in the currently available design. The hypothesis was that this new cortical bone analog would improve the uniformity of structural properties between specimens, while having mean stiffness values in the range of natural human bones. The composite replicate bones were tested under bending, axial, and torsional loads. In general, the new SGFR bones were significantly less stiff than the FFR bones, although both bone designs reasonably approximated the structural stiffnesses of natural human bones. With the exceptions of the FFR bone axial tests, the highest variability between specimens was 6.1%. The new SGFR bones had similar variability in structural properties when compared to the FFR bones under bending and torsional loading, but had significantly less variability under axial loading. Differences in epiphyseal geometry between the FFR and SGFR bones, and subsequent seating in the testing fixtures, may account for some of the differences in structural properties; axial stiffness was especially dependent on bone alignment. Stiffness variabilities for the composite replicate bones were much smaller than those seen with natural human bones. Axial strain distribution along the proximal-medial SGFR femur had a similar shape to what was observed on natural human femurs by other investigators, but was considerably less stiff in the more proximal locations.

Influence of cementless hip stems on femoral cortical strain pattern depending on their extent of porous coating

“…Major parts of the applied materials and methods of our study such as composite femora, standardized photoelastic coating, and a static loading model are validated by several studies [7,9,27,57,58] . In addition, the presented study deals with the infl uence of multiple uses of composite femora and a direct comparison with a human cadaver femur after implantation of the anatomic GHE hip stem.…”

“…Aiming to evaluate the impact of hip endoprostheses on the biomechanics of the femur, several studies basically confi rm composite femora to be suitable for such investigations [9,27,43,59,60] . Extensive testing revealed no signifi cant difference between second-generation composite femora and fresh-frozen or dried-rehydrated cadaver femora [9] .…”

Experimental and Theoretical Validation of Double Column Internal Fixation Theory for Distal Femoral Fractures

“…Наибольший поперечник в области мыщелков бедренной кости был равен 81 мм, а наименьший диаметр в средней трети диафиза бедренной кости -32 мм. Для достижения механических харак-теристик моделей бедренной кости, сходных с натуральной костью, их послойно обклеивали стеклотканью до достижения сопоставимых па-раметров жесткости при четырехточечном изги-бе [19]. после этого наименьший диаметр моде-ли бедренной кости в средней трети ее диафиза составил 43 мм.…”

Bone and Bone Surrogate Fragmentation Under Dynamic Compression

“…For example, surrogate bone material is used to evaluate the performance of machine tools used in the medical industry [1], or to obtain diagnostic information such as limb loading or implant behavior [2][3][4]. One of the primary challenges in developing a bone surrogate material is the ability to accurately mimic the material properties of natural cortical bone, including its rate and orientation mechanical response.…”