Regional variations in cortical modeling in the femoral mid-shaft: Sex and age differences

Abstract

Modern lifestyle changes may result in site-specific alterations in the skeleton. Our aim was to determine sex and age differences in regional geometry at the mid-femur. Complete cross sections from 113 individuals aged 20-97 years from a modern Australian population were obtained. A further subsample of 24, in whom the precise orientation of specimens was known, was subsequently collected. Microradiographs were made of 100-microm sections and the bone was analyzed using image processing software (Optimas, Media Cybernetics). The periosteal boundary was extracted automatically and the centroid of the periosteal outline was calculated. Fourier shape analysis was used to delineate the endocortical surface. Radial and cortical widths in each quadrant were determined. The posterior was identified by the linea aspera, and the medial and lateral were indistinguishable and therefore grouped together. For analysis, the entire sample was divided into three groups: young (20-40 years), middle (41-60 years), and old (61+ years). Raw and height-normalized values were analyzed with SPSS using t-tests, analysis of variance, and Tukey's honestly significant difference (HSD) tests. The results show that with age the femoral mid-shaft in both sexes becomes larger and more circular, with a slight shift towards the anterior. Apposition is least on the posterior and resorption greatest on the anterior, the latter being particularly evident in postmenopausal females. The greatest sex differences are seen in the middle years, lessening again in the old. We conclude that differential circumferential modeling in response to functional and postural changes occurs in both sexes with age.

Regional Heterogeneity in the Configuration of the Intracortical Canals of the Femoral Shaft

“…The statistically significant thinner cortex in older compared to the younger subjects in the anterior region, with similar trend medially and laterally, is in agreement with previous microradiographic findings on femoral midshaft sections from female donors of age similar to this study [29]. Moreover, in both the age groups, the Ct.Th tended to be thinnest anteriorly compared to medially and laterally, in agreement with earlier reports [29].…”

“…Moreover, in both the age groups, the Ct.Th tended to be thinnest anteriorly compared to medially and laterally, in agreement with earlier reports [29].…”

Metacarpal radiogrammetry: a useful indicator of bone loss throughout the skeleton?

“…It is likely that these differences stem from the fact that femoral cortical bone morphology undergoes more complex changes throughout life in response to weight bearing compared to the non-weight bearing metacarpal cortical bone. A number of studies have documented the changes in femoral cortical bone geometry with increased age between the sexes [11,17,18]. In a study on modern autopsy femoral samples Feik et al [18] found that whilst elderly men and women resemble each other in the circularity of their femoral shafts, significant differences were apparent in bone dimensions between middle and older aged females and younger and middle aged males.…”

“…A number of studies have documented the changes in femoral cortical bone geometry with increased age between the sexes [11,17,18]. In a study on modern autopsy femoral samples Feik et al [18] found that whilst elderly men and women resemble each other in the circularity of their femoral shafts, significant differences were apparent in bone dimensions between middle and older aged females and younger and middle aged males. Most notably, Feik et al [18] identified a greater antero-posterior distribution of bone in the young adult males, compared with more circular shafts in the females.…”

“…In a study on modern autopsy femoral samples Feik et al [18] found that whilst elderly men and women resemble each other in the circularity of their femoral shafts, significant differences were apparent in bone dimensions between middle and older aged females and younger and middle aged males. Most notably, Feik et al [18] identified a greater antero-posterior distribution of bone in the young adult males, compared with more circular shafts in the females. Females also exhibited little change in bone dimensions prior to the menopause and subsequently demonstrated greater anterior apposition and overall resorption occurring earlier than in the males, while males showed an increase in all bone parameters measured between the young and middle adults.…”