Intrapopulation variability in mineralization density at the human femoral mid‐shaft

Abstract

One of several microstructural variables known to affect the mechanical properties of bone is the degree of mineralization of bone matrix. The aim of this study was to examine mineralization density, and its variability with age and sex, from a biomechanical perspective. Histological sections, prepared from mid-shaft femora obtained at autopsy from 40 individuals, were imaged using quantitative backscattered electron microscopy. Each cross-section montage was divided into 48 segments according to anatomical position. Mean grey-level values were quantified for each segment. One-way ANOVA with Tukey HSD post hoc tests were used to test for differences in mineralization between segments, age groups and sexes. Results showed a decrease in overall degree of mineralization density with adult age, but an increase in its coefficient of variation. Degree of mineralization was significantly lower in the periosteal third of the cortex, particularly in the antero-lateral aspect. This pattern was most prevalent amongst the youngest individuals in the sample. Whereas males between ages 45-64 years had a higher average degree of mineralization than females, the opposite was true of the older age group. Mineralization significantly decreased between middle and older age groups in males, but not in females. Despite limited consistencies in the location of high and low average mineralization bone through the cortex, the degree of interindividual variation, even within a single age and sex group, overwhelmed population level trends. The patterns of variability identified in this study are consistent with results of an analysis of collagen fibre orientation using the same sample material.

The degree of bone mineralization is maintained with single intravenous bisphosphonates in aged estrogen-deficient rats and is a strong predictor of bone strength

“…At least two other studies have evaluated bone mineral heterogeneity. Goldman et al reported there was a significant increase in mineral heterogeneity in the midfemoral cortex among 45-64 year old females and males [29]. Other investigators reported an overall reduction in the mineralization, crystallinity and type-B carbonation in males aged 60 years or older, indicating a reduction in heterogeneity with aging [30].…”

Age-related changes in porosity and mineralization and in-service damage accumulation

“…via previous proposals, lessen damageability. In addition, mineralization of mature bone has been shown in some studies to decrease or remain unchanged with age (Thompson, 1980;Yeni et al, 1998;Currey, 1979;Currey et al, 1996;Goldman et al, 2003) while microdamage has been shown to increase with age (Schaffler et al, 1995;Norman and Wang, 1997;Fazzalari et al, 1998;Zioupos, 2001a, b). Thus, it would appear that there may be competing biological processes affecting tissue quality and the outcome of elevation or suppression of intracortical remodeling on bone damage accumulation.…”

The petrous bone—A new sampling site for identifying early dietary patterns in stable isotopic studies

“…The available data on bone turnover rates is mainly derived from measuring the uptake of 14 C in body tissues following the ''bomb peak'' of the late 1950s and early 1960s (Libby et al, 1964; Baxter, 1977, 1979;Wild et al, 2000;Geyh, 2001). The individual replacement rates are difficult to estimate, as they depend on various factors including health and nutrition (Oelbermann and Scheu, 2002;Voigt and Matt, 2004; Metoka et al, 2006), physical activity (Frost, 1988) as well as age and sex (Goldman et al, 2003;David et al, 2005). Furthermore, replacement rates vary between different types of bone tissue (compact or trabecular bone) and consequently between different skeletal elements (Sealy et al, 1995).…”