最适配比的新型依诺肝素钠骨水泥与普通骨水泥在家兔体内的生物力学对比

Biomechanical comparison between the new enoxaparin sodium cement and the ordinary bone cement in rabbits

目的比较最适配比的新型依诺肝素钠骨水泥与普通骨水泥在家兔体内的生物力学特性。方法选20只新西兰大耳白兔(购自望都县彤辉养殖有限公司),随机分为A、B两组,每组10只,A组左后肢记为A1组,植入最适配比的新型依诺肝素钠骨水泥长方体试件,右后肢记为A2组,植入普通骨水泥长方体试件,B组左后肢记为B1组,植入最适配比的新型依诺肝素钠骨水泥圆柱体试件,右后肢记为B2组,植入普通骨水泥圆柱体试件,1 d后A、B两组各随机选出5只家兔,将体内试件取出,A组试件行四点弯曲实验,计算各标本的弯曲模量和弯曲强度,分别进行配对样本t检验,B组试件行轴向压缩实验,计算各标本的压缩强度,并进行配对样本t检验;4周后将A、B两组剩余家兔体内试件取出,重复上述实验。结果1 d时,A1组弯曲模量为(2.28±0.05)GPa(1 GPa=7.5×10^8 mmHg),A2组弯曲模量为(2.49±0.13)GPa,两组对比差异无统计学意义(t=-0.991,F=0.982,P>0.05),A1组弯曲强度为(97.95±0.32)MPa(1 MPa=7.5×10^3 mmHg),A2组弯曲强度为(99.86±0.47)MPa,两组对比差异无统计学意义,(t=-1.490,F=2.212,P>0.05),B1组压缩强度为(88.75±0.42)MPa,B2组压缩强度为(90.17±0.39)MPa,两组对比差异无统计学意义(t=-0.893,F=0.791,P>0.05;4周时,A1组弯曲模量为(2.05±0.10)GPa,A2组弯曲模量为(2.44±0.23)GPa,两组对比差异无统计学意义(t=-0.892,F=0.803,P>0.05),A1组弯曲强度为(94.24±0.29)MPa,A2组弯曲强度为(98.58±0.35)MPa,两组对比差异无统计学意义(t=-1.802,F=3.241,P>0.05),B1组压缩强度为(86.21±0.22)MPa,B2组压缩强度为(91.67±0.54)MPa,两组对比差异无统计学意义(t=-1.572,F=2.470,P>0.05)。结论最适配比新型依诺肝素钠骨水泥植入家兔体内后其机械性能未发生明显改变,符合临床应用的生物力学要求。

Objective To compare the biomechanical properties of new enoxaparin sodium cement and common bone cement in rabbits.Methods Twenty New Zealand white rabbits were randomly divided into two groups:group A and group B,with 10 rabbits in each group.The left hind limb of group A served as group A1,and the new enoxaparin sodium cement rectangular specimen with the best proportion was implanted.The right hind limb was recorded as group A2,and the ordinary bone cement rectangular specimen was implanted.The left hind limb of group B served recorded as group B1,and the new enoxaparin sodium cement cylindrical specimen with the best proportion was implanted.The right hind limb served as group B2,and the cylinder specimen of ordinary bone cement was implanted.One day later,five rabbits were randomly selected from group A and group B,and the in vivo specimens were taken out.The specimens in group A were subjected to four-point bending test to calculate the bending modulus and bending strength of each specimen,and paired samples t test was carried out respectively.The difference was statistically significant with P<0.05.The specimens in group A were subjected to axial compression test to calculate the compression strength of each specimen,and paired samples t test was carried out with P<0.05 as the difference.Four weeks later,the specimens were taken out from the remaining rabbits in groups A and B,and the above experiment repeated.Results At the first day,the bending modulus of A1 group was(2.28±0.05)GPa(1 GPa=7.5×10^8 mmHg),and that of A2 group was(2.49±0.13)GPa.There was no significant difference between the two groups(t=-0.991,F=0.982,P>0.05),The bending strength of A1 group was(97.95±0.32)MPa(1 MPa=7.5×10^3 mmHg),and that of A2 group was(99.86±0.47)MPa.There was no significant difference between the two groups(t=-1.490,F=2.212,P>0.05),The compressive strength of B1 group was(88.75±0.42)MPa,and that of B2 group was(90.17±0.39)MPa.There was no significant difference between the two groups,(t=-0.893,F=0.791,P>0.05);At 4 weeks,the bending modulus of group A1 was(2.05±0.10)GPa,and that of group A2 was(2.44±0.23)GPa.There was no significant difference between the two groups(t=-0.892,F=0.803,P>0.05),The bending strength of A1 group was(94.24±0.29)MPa,and that of A2 group was(98.58±0.35)MPa.There was no significant difference between the two groups,(t=-1.802,F=3.241,P>0.05,The compressive strength of B1 group was(86.21±0.22)MPa,and that of B2 group was(91.67±0.54)MPa.There was no significant difference between the two groups,(t=-1.572,F=2.470,P>0.05).Conclusion The mechanical properties of the new enoxaparin bone cement with the best proportion implanted in the rabbit did not change significantly,which met the biomechanical requirements of clinical application.