磷酸钙强化椎弓根螺钉的动态生物力学研究  

Biomechanical performance of pedicle screw augmented with an injectable calcium phosphate cement: an in vivo study

作　　者：高明暄[1] 甄平[1] 薛云[1] 田琦[1] 

机构地区：[1]兰州军区兰州总医院骨科&全军创伤骨科中心,兰州730050

出　　处：《医用生物力学》2009年第5期384-389,共6页Journal of Medical Biomechanics

摘　　要：目的研究磷酸钙骨水泥强化椎弓根螺钉后生物力学强度的体内动态变化。方法成年雌性绵羊12只,年龄4～6岁,体重33～45 kg。经L1～L6椎体双侧椎弓根分直接植入、CPC强化和PMMA强化3种植钉方法植入椎弓螺钉,每只动物体内植钉方法按平衡不完全随机进行分配,每种方法各植4枚。植钉后动物被随机分配至术后1 d,4 w,12 w和24 w4个观察时间点,每点3只。在观察点获取植钉腰椎标本,测定螺钉的轴向拔出力和拔出能量吸收值,对相同时间点各植钉方法之间和同一植钉方法各时间点之间的指标对比分析。结果4个观察时间点动物的骨密度分别为:(0.923±0.082)g/cm2,(0.910±0.098)g/cm2,(0.952±0.123)g/cm2和(0.912±0.126)g/cm2,组间均未见显著差异(P(0.05);在术后1d,4w,12w和24w4个观察时间点CPC强化组的最大轴向拔出力(Fmax)依次为:(893.13±63.91)N,(916.50±109.88)N,(1 022.04±73.85)N和(1 104.91±112.33)N;拔出能量吸收值(EAV)与相应的Fmax呈正相关(P(0.001)。同一方法各时间点内的Fmax和EAV均无显著性差异(P(0.28)。相同时间点,CPC强化组的Fmax和EAV均显著高于对照组(P(0.001)。另外,除24周的EAV二者无差异(P(0.18)外,PMMA强化组两项指标均高于CPC强化组(P(0.003)。结论用CPC强化能显著提高椎弓根螺钉的固定强度,且强化作用在体内是动态稳定的;在椎弓根螺钉强化方面,CPC是PMMA理想的替代材料。Objective To investigate the long-term changes of fixation strength of pedicle screw augmented with calcium phosphate cement in vivo. Method Twelve pedicle screws were bilaterally planted in to six lumbar vertebrae of each sheep,including 4 non-augmented as control,4 augmented with calcium phosphate cement（CPC） and 4 augmented with polymethylmethacrylate（PMMA）.A total of twelve female adult sheep were operated,and they were randomized into four study periods of 1 day,4 weeks,12 weeks and 24 weeks after operation.At the end of every assigned study period,the animals were killed and lumbar vertebrae were harvested.Then axial pull-out tests conducted on the pedicle screws of the isolated vertebrae.The maximum pull-out force（F_max） and energy absorption value（EAV） of the different screw planting methods at the same time and those of the same screw planting method but at the different study periods were compared by twos,respectively. Result The mean BMD was（0.923±0.082） g/cm2 in the group o...更多f one day after surgery,（0.910±0.098）g/cm2 group at 4 w,（0.952±0.123）g/cm2 group at 12w and（0.912±0.126）g/cm2 group at 24w.There was no significant difference in the bone mineral density（BMD） of the animals between every two group（P﹥0.05）.The mean maximum pull-out force in the CPC group was（893.13±63.91）N 24 hours after operation,（916.50±109.88）N at 4 w,（1022.04±73.85）N at 12 w and（1 104.91±112.33）N at 24w.A positive correlation existed between F_max and EAV（P﹤0.001）.No significant difference in Fmax and EAV was found among the 1-day,4-week,12week and 24-week control group,so were CPC group and PMMA group（P﹥0.28）.At the end of every study period,the Fmax and EAV of CPC group were unanimously greater than those of control group（P﹤0.001）.And the F_max and EAV of PMMA group were statistically greater than those of CPC group（P﹤0.003） but an exception,the 24-week EAV（P﹥0.18）. Conclusions Results of this research demonstrated that the

关 键 词：磷酸钙 椎弓根螺钉强化 轴向拔出力 体内 生物力学 固定 

分 类 号：R318.01[医药卫生—生物医学工程]