| First Author | Jepsen KJ | Year | 2001 |
| Journal | J Bone Miner Res | Volume | 16 |
| Issue | 10 | Pages | 1854-62 |
| PubMed ID | 11585350 | Mgi Jnum | J:72736 |
| Mgi Id | MGI:2153502 | Doi | 10.1359/jbmr.2001.16.10.1854 |
| Citation | Jepsen KJ, et al. (2001) Bone brittleness varies with genetic background in A/J and C57BL/6J inbred mice. J Bone Miner Res 16(10):1854-62 |
| abstractText | The contribution of genetic and environmental factors to variations in bone quality are understood poorly. We tested whether bone brittleness varies with genetic background using the A/J and C57BL/6J inbred mouse strains. Whole bone four-point bending tests revealed a 70% decrease in postyield deflection of A/J femurs compared with C57BL/6J, indicating that A/J femurs failed in a significantly more brittle manner. Cyclic loading studies indicated that A/J femurs accumulated damage differently than C57BL/6J femurs, consistent with their increased brittleness. Differences in matrix composition also were observed between the two mouse strains. A/J femurs had a 4.5% increase in ash content and an 11.8% decrease in collagen content. Interestingly, a reciprocal relationship was observed between femoral geometry and material stiffness; this relationship may have contributed to the brittle phenotype of A/J femurs. A/J femurs are more slender than those of C57BL/6J femurs; however, their 47% smaller moment of inertia appeared to be compensated by an increased tissue stiffness at the expense of altered tissue damageability. Importantly, these differences in whole bone mechanical properties between A/J and C57BL/6J femurs could not have been predicted from bone mass or density measures alone. The results indicated that bone brittleness is a genetically influenced trait and that it is associated with genetically determined differences in whole bone architecture, bone matrix composition, and mechanisms of cyclical damage accumulation. |
