大鼠骨量与骨生物力学特性之间的相关性

目的　观察骨质疏松模型大鼠骨量与骨强度之间的关系。方法　采用扇形束双能 Ｘ 线吸收法（ Ｄ Ｘ Ａ）测量５０只 Ｓ Ｄ 大鼠全身、股骨和腰椎（ Ｌ４ Ｌ６）骨量（骨矿含量和密度）。采用三点弯曲试验测量股骨抗弯和压缩试验测量椎体（ Ｌ４）抗压力学特性。结果　鼠体重和鼠全身骨量及股骨骨量与股骨抗弯系数、弹性弯距和最大弯距呈显著正相关（ｒ＝ ０５５２～０８２６， Ｐ＜ ０００１）；鼠体重与股骨的弹性应力（ｒ＝－ ０３６０， Ｐ＜ ００５）和抗弯强度（ｒ＝ － ０３３８， Ｐ＜ ００５）呈显著负相关；腰椎骨矿密度与椎体弹性载（ｒ＝０３２５， Ｐ＜ ００５）和最大载（ｒ＝ ０３４０， Ｐ＜ ００５）呈显著正相关，与弹性应力、抗压强度和弹性模量相关无显著性（ｒ＝ ０１５３～０２７５， Ｐ＞ ００５）。结论　大鼠股骨和全身骨量与抗弯系数、弹性弯距和最大弯距显示高度相关性

Correlations between bone mechanical properties and bone mass in rats

Objective\ The relationship between bone mass(BMC and BMD) and bone strength was investigated in rat model of osteoporosis.Methods Bone mass in whole body,femur and lumbar spines(L4\|L6) was measured by dual energy X\|ray absorptiometry(DXA) in 50 SD rats.The bending mechanical property of femur was measured by three\|point bending test and the compression mechanical property of vertebra was measured by compression test. Results \ Significant correlations were found between body weight,bone mass of the whole body or femur and bend coefficient,elastic transverse distance or ultimate transverse distance of the femur ( r=0 552 to 0 826,P<0 001 ).There were significant negative correlations between elastic stress( r=-0 360,P<0 05 ) or bending strength ( r=-0 338,P<0 05 ) of the femur and body weight.The lumbar spines(L4\|L6) BMD correlated with elastic load ( r=0 325,P<0 05 ) or maximal load ( r=0 340,P>0 05 ),but not with elastic stress,bending strength or elastic modulus ( r=0 153 to 0 275,P<0 05 ) at the lumbar spine(L4). Conclusions\ There are highly significant correlations between bending coefficient,elastic transverse distance or ultimate transverse distance and bone mass of the femur or whole body in rats.