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1. Introduction
Numerous papers have evaluated the mechanical properties of bone and have presented the opinion that these values can be determined not only by bone density but also by the properties of single trabeculae and the structure of the trabecular part of the bone [1–3]. In clinical practice, one of the most commonly applied methods of evaluating bone density is dual energy X-ray absorptiometry (DEXA). This method allows the determination of bone mineral density (BMD) and bone mineral content (BMC) as demonstrated by Hansson et al. [4], McBroom et al. [5], Beck et al. [6], and Cody et al. [7], which are used to indirectly determine fracture risk. Investigating density with DEXA is favorable because it is quick and the results are available immediately. However, the disadvantage of this method is that it does not consider the complexity of the structure of trabeculae.
To evaluate the structure of trabecular bone in vitro, computer microtomography (microCT) is commonly applied. This makes it possible to generate bone images with an accuracy of 6–8 microns. Based on images of the inner part of the bone obtained as a result of such investigations, micromechanical models of the bone structure subject to finite element (FE) calculations can be developed [8–11]. However, the application of this technique in vivo in clinical practice is difficult. The disadvantage of this technique is that it is time consuming, depending on the assumed performance accuracy. Currently, it is impossible to apply microCT to patients.
In clinical practice, it is possible to image trabecular bone using techniques such as multidetector computer tomography (MDCT) or high-resolution magnetic resonance imaging (HRMRI). The resolution of images obtained using these techniques is about 100–300 microns at a slice density ranging from 300–500 microns [12–16]. At present, however, the availability of these techniques is limited.
Time limitations are one of the major problems of medical investigations because X-ray investigation is harmful and requires the patient to stay motionless. In such cases, limiting the time of the medical investigation is beneficial for the patient, but this usually leads to a reduction in the resolution of the test.
In numerous papers, the effects of increasing the voxel size of the FE model to a larger size than that obtained from microCT on...