Document Detail

Biological co-adaptation of morphological and composition traits contributes to mechanical functionality and skeletal fragility.
MedLine Citation:
PMID:  17922614     Owner:  NLM     Status:  MEDLINE    
A path analysis was conducted to determine whether functional interactions exist among morphological, compositional, and microstructural traits for young adult human tibias. Data provided evidence that bone traits are co-adapted during ontogeny so that the sets of traits together satisfy physiological loading demands. However, certain sets of traits are expected to perform poorly under extreme load conditions. INTRODUCTION: Previous data from inbred mouse strains suggested that biological processes within bone co-adapt morphological and compositional traits during ontogeny to satisfy physiological loading demands. Similar work in young adult humans showed that cortical tissue from slender tibias was stiffer, less ductile, and more susceptible to accumulating damage. Here we tested whether the relationships among morphology and tissue level mechanical properties were the result of biological processes that co-adapt physical traits, similar to those observed for the mouse skeleton. MATERIALS AND METHODS: Cross-sectional morphology, bone slenderness (Tt.Ar/Le), and tissue level mechanical properties were measured from tibias from 14 female (22-46 yr old) and 17 male (17-46 yr old) donors. Physical bone traits measured included tissue density, ash content, water content, porosity, and the area fractions of osteonal, interstitial, and circumferential lamellar tissues. Bivariate relationships among traits were determined using linear regression analysis. A path analysis was conducted to test the hypothesis that Tt.Ar/Le is functionally related to mineralization (ash content) and the proportion of total area occupied by cortical bone. RESULTS: Ash content correlated negatively with several traits including Tt.Ar/Le and marrow area, indicating that slender bones were constructed of tissue with higher mineralization. Path analysis revealed that slender tibias were compensated by higher mineralization and a greater area fraction of bone. CONCLUSIONS: The results suggest that bone adapts by varying the relative amount of cortical bone within the diaphysis and by varying matrix composition. This co-adaptation is expected to lead to a particular set of traits that is sufficiently stiff and strong to support daily loads. However, increases in mineralization result in a more brittle and damageable material that would be expected to perform poorly under extreme load conditions. Therefore, focusing attention on sets of traits and the relationship among traits may advance our understanding of how genetic and environmental factors influence bone fragility.
Steven M Tommasini; Philip Nasser; Bin Hu; Karl J Jepsen
Related Documents :
25326144 - Bone geometry, volumetric bone mineral density, microarchitecture and estimated bone st...
21961004 - Bacterial cellulose-hydroxyapatite nanocomposites for bone regeneration.
6507084 - Decreased radial bone mass in colles' fracture.
16123024 - Age-dependent fatigue behaviour of human cortical bone.
24669564 - The impact of postoperative pain on early ambulation after hip fracture.
24293934 - Bear maul injuries in maxillofacial region: our experience.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research     Volume:  23     ISSN:  1523-4681     ISO Abbreviation:  J. Bone Miner. Res.     Publication Date:  2008 Feb 
Date Detail:
Created Date:  2008-01-16     Completed Date:  2008-04-21     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  8610640     Medline TA:  J Bone Miner Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  236-46     Citation Subset:  IM    
New York Center for Biomedical Engineering, CUNY Graduate School, Department of Biomedical Engineering, City College of New York, New York, New York, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Bone Density*
Fractures, Stress*
Middle Aged
Models, Biological
Sex Characteristics
Stress, Mechanical*
Tibia / anatomy & histology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Clinical and cellular manifestations of OSTM1-related infantile osteopetrosis.
Next Document:  Bone fragility contributes to the risk of fracture in children, even after moderate and severe traum...