A cross-sectional study on the age-related cortical and trabecular bone changes at the femoral head in elderly female hip fracture patients

Abstract

Bone is in a continuous state of remodeling whereby old bone is absorbed and new bone is formed in its place. During this process, new formations reinforce the bone in the direction of the dominant stress trajectories through a functional adaptation. In normal aging, the balance between bone resorption and formation can be shifted. How this affects the functional adaptation remains to be investigated. Furthermore, how or whether the bone continues to change beyond the age of 85 is not yet studied in detail. In this study we examined the age-related changes in the cortical and trabecular bone in old age, and assessed whether we can find evidence of the presence of functional adaptation. We measured cortical and trabecular parameters from micro-computed tomography scans of the femoral head extracted from hip fracture patients between the age of 70 and 93 years. A significant decrease in global trabecular bone mineral density (38.1%) and cortical thickness (13.0%) was seen from the 9th to the 10th decade of life. The degree of anisotropy was maintained globally as well as locally in both high and low stress regions. The local trabecular bone mineral density decreased in both high stress and low stress regions between the 9th and 10th decade of life with similar trends. This suggests that the role of functional adaptation in maintaining the bone structural integrity in old age may be limited. This study highlights the need for a controlled clinical trial examining the cause of the continued bone degradation throughout old age.

Age-Related Trends in the Trabecular Micro-Architecture of the Medial Clavicle: Is It of Use in Forensic Science?

“…A lack of change for DA in the clavicle (Figure 4) contrasts with the increase in DA reported in other studies (Ding et al, 2002;Gong et al, 2005;Cui et al, 2008;Djuric et al, 2010) for the proximal femur and tibia. However, in some cases (Chen et al, 2013;Whitmarsh et al, 2019), DA exhibits no significant trend with age, or this structural modification is not detected until later in life (Cui et al, 2008). For Cui et al (2008), DA drastically changed after the seventh decade was surpassed, but remained largely unchanged until this stage.…”

“…Histomorphometric changes in the cancellous bone of regions in skeleton such as the decrease in BV/TV with age are well-established (Ding et al, 2002;Gong et al, 2005;Chen et al, 2008Chen et al, , 2010Chen et al, , 2013Cui et al, 2008;Djuric et al, 2010;Thomsen et al, 2015;Whitmarsh et al, 2019). The loss of bone quantity is considered to be the most important factor affecting structural integrity with age, but "bone quality" including thinning, number, and connectivity of the trabeculae influence the mechanical competency of bone (Hildebrand et al, 1999;Compston, 2006;Djuric et al, 2010;Vale et al, 2013).…”

“…The following morphometric indices were then generated: bone volume fraction (BV/TV), specific bone surface for a given volume (BS/BV), in addition to mean trabecular thickness (Tb.Th), number (Tb.N), and spacing (Tb.Sp). In addition, a measure of the connectivity, connectivity density (Conn.D) and degree of anisotropy (DA), which defines the preferred orientation of the trabecular bone in a given volume from highly isotropic (0) to anisotropic (1), were also performed using BoneJ (Doube et al, 2010), an open access ImageJ plug-in (Cui et al, 2008;Chen et al, 2013;Vale et al, 2013;Whitmarsh et al, 2019). In order to validate the results for BV/TV, Tb.Th and Tb.Sp, these measures were also calculated using BoneJ so the trends from both software packages could be compared.…”

“…From this, along with the mean gray level value taken from the histogram for each specimen, the volumetric tissue mineral density ( v TMD) was determined. Volumetric bone mineral density ( v BMD) could then be calculated using the following equation (Meganck et al, 2009;Adams et al, 2018;Greenwood et al, 2018;Vidal et al, 2018;Whitmarsh et al, 2019) vBMD = vTMD x BV/TV…”

“…The inner micro-structure of the clavicle has not been examined at length and in the forensic context it may lead to the development of innovative and quantitative analytical methods. Such information can be acquired through the application of micro-computed tomography (µ-CT), a non-destructive imaging technique which has been used previously to quantify structural alterations to the network of trabeculae mostly in the epiphyses of long bones and vertebral bodies implicated for the increased risk of fracture with age (Müller and Rüegsegger, 1997;Müller et al, 1998;Hildebrand et al, 1999;Ulrich et al, 1999;Eckstein et al, 2007;Chen et al, 2008Chen et al, , 2010Chen et al, , 2013Cui et al, 2008;Lochmüller et al, 2008;Djuric et al, 2010;Viguet-Carrin et al, 2010;Thomsen et al, 2013Thomsen et al, , 2015Vale et al, 2013;Greenwood et al, 2018;Whitmarsh et al, 2019). The objectives of this study were to examine the inner structure of the medial clavicle by µ-CT, in order to characterize changes in the trabecular microstructure as a function of age as well as examine the implications and potential input of this work in future case studies on aging providing a more objective analytical basis for age estimation in forensic science.…”