Drifting Diaphyses: Asymmetry in Diametric Growth and Adaptation Along the Humeral and Femoral Length

Abstract

This study quantifies regional histomorphological variation along the human humeral and femoral diaphysis in order to gain information on diaphyseal growth and modeling drift patterns. Three thin sections at 40, 50, and 60% bone length were prepared from a modern Mexican skeletal sample with known age and sex to give a longitudinal perspective on the drifting cortex (12 adults and juveniles total, 7 male and 5 female). Point-count techniques were applied across eight cross-sectional regions of interest using the starburst sampling pattern to quantify percent periosteal and endosteal primary lamellar bone at each diaphyseal level. The results of this study show a posterio-medial drift pattern in the humerus with a posterior rotational trend along the diaphysis. In the femur, we observed a consistent lateral to anteriolateral drift and an increase in primary lamellar bone area of both, periosteal and endosteal origin, towards the distal part of the diaphysis. These observations characterize drifting diaphyses in greater detail, raising important questions about how to resolve microscopic and macroscopic cross-sectional analysis towards a more complete understanding of bone growth and mechanical adaptation. Accounting for modeling drift has the potential to positively impact age and physical activity estimation, and explain some of the significant regional variation in bone histomorphology seen within (and between) bone cross-sections due to differing ages of tissue formation. More study is necessary, however, to discern between possible drift scenarios and characterize populational variation.

Three‐dimensional reconstruction of Haversian systems in human cortical bone using synchrotron radiation‐based micro‐CT: morphology and quantification of branching and transverse connections across age

“…; Maggiano, ; Maggiano et al. . Numerous studies have also drawn attention to regional variation of osteon properties caused by different strain environments (Hert et al.…”

“…Lateral and dichotomous branching show diverse frequencies across all ages, but are the least frequent in the individual age 27 years, which showed larger volumes of primary lamellar bone within the sample. As studies on regional tissue variation in human and non-human primate cortical bone show, even when a standardized region is sampled, variability in drift magnitude and remodeling rates can cause tissue to have variable ages and origins (McFarlin et al 2008;Goldman et al 2009;Maggiano, 2015;Maggiano et al 2015. Numerous studies have also drawn attention to regional variation of osteon properties caused by different strain environments (Hert et al 1994;Iwaniec et al 1998;Chan et al 2007;Skedros et al 2007).…”

“…Despite differing influences on and functions for the BMU, the net result of remodeling is that the accumulation of Haversian systems is fairly regular on the whole. However, the specific regional distribution of osteons has been shown to vary considerably across diaphyseal cross-sections, emphasizing the complexity of remodeling and bone growth and adaptation (McFarlin et al 2008;Goldman et al 2009;Maggiano et al 2011Maggiano et al , 2015Pazzaglia et al 2013;Maggiano, 2015).…”

Mechanical and metabolic interactions in cortical bone development

“…Another complicating factor in comparing histological structures in immature individuals is cortical drift. During growth, modeling causes bone shape to “drift” in the direction dictated by the mechanical environment, directing the distribution of tissue layers within the cortex (Enlow, ; Wu et al, ; Maggiano et al, ). Therefore, the histological ROIs may have been placed on cortical bone sections that formed at various times across individuals' lifetimes.…”

Cortical Histomorphometry of the Human Humerus During Ontogeny

“…Histomorphometric studies have explored cortical drift, the gross geometry of the human femur [1,2] and humerus [3][4][5], and bone remodeling with age in the iliac bone [6]. Recently, relationships between secondary osteon area and mechanical loading have been reported for the femur, humerus and rib [7].…”