Continuing bone growth throughout life: A general phenomenon

Abstract

Cross-sectional data on 2799 subjects from five different populations and longitudinal data on 113 older adults indicate continuing adult bone growth in the second metacarpal. Similar B-decade increases in the size of the cranium confirm continuing bone growth as a general phenomenon not necessarily related to weightbearing or flexion stress and representing an increase of approximately 10% in skeletal volume concomitant with the major age-associated decrease in skeletal mass.In 1964, Smith and Walker provided cross-sectional radiographic evidence for continuing "expansion" of the femur in women aged 45-90. Trotter and Peterson ('67), using skeletalized femora have given confirmation to this trend. Epker, Kelin and Frost ('65) similarly reported an increase in the size of the periosteal envelope through the seventh decade in rib cross sections of subjects of both sexes. Moore ('55) earlier published separate cross-sectional data indicating continuing growth of the cranial vault through late adulthood, thus indicating that weight-bearing, flexion-stressed bones axe not unique in the apparent property of continuing growth.With cross-sectional data from five populations at hand, and having both longterm and short-term longitudinal data from a single ongoing study population, we have been concerned with three aspects of the problem of continuing bone growth. First, there is the question of such adult growth in various bones throughout the body, weight-bearing, flexion-stressed and otherwise. Second, there is the problem of generalization-whether such bone expansion is population-limited or not and sexspecific or not. Third, there is the problem of confinnation of such continuing growth on an individual basis in order to rule out artifacts of sampling and differential survival.It is the purpose of the present study to explore continuing bone growth in two populations from the United States and AM. J. Pays. ANTHROP., 26: 313-318.three Central American populations, using longitudinal data to further test for individual trends. It is the additional purpose of this study to investigate adult bone growth in both weight-bearing bone and in bone not subject to compression or flexion stress in order to determine whether such mechanical factors play a necessary role in continuing bone growth. METHODS AND MATERIALSThis study is based upon vernier caliper measurements of the second metacarpal on pastero.anterior hand radiographs from five different population samples, one skeletal and four living. 2799 subjects are represented in the cross-sectional study.

Limb bone bilateral asymmetry: variability and commonality among modern humans

“…Relative to other measures within elements, diaphyseal breadths consistently exhibit the most asymmetry, absolute and directional, followed by lengths and articular dimensions. In part, the increased asymmetry in external diaphyseal breadths may be due to the potential for continuing subperiosteal expansion of long bone cortices throughout life, after cessation of growth in length (and presumably articular size) (Garn et al, 1967;Lazenby, 1990;Heaney et al, 1997;Ahlborg et al, 2003). Thus, diaphyseal breadth asymmetry may increase in adults relative to length and articular asymmetry.…”

Identification of homogeneous genetic architecture of multiple genetically correlated traits by block clustering of genome-wide associations

“…CVs, calculated as root-mean-square average, (41) ranged from 1.0% (bone length) to 7.0% (midshaft endosteal diameter). Metacarpal length and midshaft width were measured directly, whereas cortical cross-sectional indices, such as metacarpal cortical thickness (MCT, mm), cortical index (MCI, %), and section modulus (MZ, mm 3 ), were calculated in the middle of bone diaphysis (42)(43)(44) ; values of metacarpals 2, 3, and 4 were averaged.…”

Thigh muscle volume in relation to age, sex and femur volume

“…In the shafts, those small changes are conveyed through thinning of the cortex, with the total bone cross section undergoing no or only small changes (Garn et al 1967;Wilks et al 2009). Another option would be to use femur length since this does not change after growth plate fusion and the cessation of longitudinal growth, and femur length cubed might be used to provide the correct dimensions for normalising thigh muscle volume and provide a better estimate of changes in muscle mass.…”