【作者】 徐文华；

【导师】 马勇；

【作者基本信息】 江西医学院 ， 外科学， 2005， 硕士

【摘要】 目的:探讨骨密度与椎体的生物力学的关系;比较国产骨水泥(PMMA)和注射性骨泰(CPC)在椎体后凸成形术(KP)中对不同骨密度椎体的生物力学恢复情况,为临床提供一定参考。方法:取福尔马林浸泡的胸腰段脊柱标本(L1～L5),X线摄片无明显病理异常,双能X线吸收骨密度仪(DEXA)测定椎体骨密度(BMD)。将标本游离成单个椎体,去除椎间盘及附件等。共选择了60 个椎体,按BMD 分对照组(正常)、轻中度和重度骨质疏松组,即A 组(n=26)、B 组(n=16)和C 组(n=18)。用材料试验机轴向加载,压缩椎体高度25%,制造椎体压缩骨折,确定椎体的初始压缩强度和刚度。对每组骨折椎体进行球囊扩张椎体后凸成形术(KP),记录球囊扩张体积,随机注入PMMA 或CPC,观察它们外渗漏情况及注入量。测高后再次加载压缩达椎体高度25%,确定术后椎体的压缩强度和刚度。椎体标本在骨折前及球囊扩张椎体后凸成形术后均测量椎体平均高度。数据处理:数据均以X±S 方式表示,用SPSS 11.5 进行统计处理:BMD 与椎体压缩强度和刚度间用相关分析,三组间BMD、椎体压缩强度和刚度的比较用单因素方差分析(ANOVA)分析;每组组内不同材料间椎体术前椎体压缩强度和刚度及术后不同材料处理后效果行两样本的独立t 检验,同一材料术前、术后椎体压缩强度和刚度行配对t 检验,有意义者再行椎体压缩强度和刚度恢复百分率处理;椎体高度恢复行百分率处理;显著性水平置于P=0.05。结果:对照组、轻中度和重度骨质疏松组平均骨密度分别为(1.098±0.147)、(0.650±0.137)和(0.393±0.060)g/cm2;三组间的压缩强度分别为(6.775±1.952)、(3.450±0.909)和(2.395±0.697)KN;刚度分别为(2.216±0.897)、(1.391±0.461)和(0.942±0.206)KN/mm。BMD 与椎体压缩强度和刚度呈正相关关系;三组间的BMD、最大抗压力和刚度均存在显著性差异(P<0.01)。各组内不同材料间术前椎体骨密度、椎体压缩强度和刚度无统计学意义(P>0.05);术后:使用CPC 和PMMA 材料后A 组未能恢复椎体的初始压缩强度和更多还原

【Abstract】 Objective: To investigate the relation of vertebral bodies(VB) bonemineral density (BMD) and biomechanics; to compare the biomechanicalchanges of isolated, fractured VBs after treatment by Kyphoplasty(KP)with one of two domestic cements: polymethylmetharylate(PMMA) orinjectable calcium phosphate cement(CPC), and to provide the data forthe clinical application.Methods: Sixty VBs were harvested from nine female and three maleembalmed cadavers (L1～L5), Taken photos using X-ray, screened for BMDusing DEXA and separated into individual VB (n=60). According to theirBMD, all VBs were divided into 3 groups: normal group( A group, n=26);osteoporotic group( B group, n=16); and serious osteoporotic group( Cgroup, n=18). All VBs were compressed in a materials testing machineto determine initial intensity and stiffness values, were assigned toone of two groups and were then repaired using KP with the domesticPMMA or CPC. Compression was continued until the average height of theVB was decreased by 25% of the average initial VB height. Pretreatmentand post-treatment heights were measured, and the repaired VBs wererecompressed to determine post-treatment intensity and stiffnessvalues. The volumes of the expanded IBT(an inflatable tamp) andinjected cement were recorded. All data were expressed with X ±S andtreated with SPSS 11.5. One-way ANOVA was used to compare BMD,pretreatment intensity and stiffness values for study groups, whereaslinear relationships between BMD and pretreatment intensity orstiffness values were assessed with Bivariate correlations;Paired-Samples T test was used to assess pretreatment andpost-treatment intensity and stiffness values for one material in samegroup, whereas compare pretreatment or post-treatment intensity andstiffness values between the different materials in same group withIndependent-Samples T test; With a significance level of 0.05.Results: The average BMD is 1.098±0.147 g/cm2 , 0.650±0.137 g/cm2 and0.393±0.060g/cm2, in A, B and C group respectively. The pretreatmentintensity and stiffness were 6.775±1.952KN, 2.216±0.897KN/mm; 3.450±0.909 KN,1.391±0.461 KN/mm; 2.395±0.697KN, 0.942±0.206KN/mm ,respectively. A significant positive correlation was seen between BMDand initial intensity or stiffness values. The pretreatment intensityand stiffness values were recovered in all VBs of B and C groups, whereasnot recovered in A group. The heights of VB were recovered to 95% ofinitial ones. IBT volume: CPC(2.050±0.196)ml, PMMA(2.053±0.211)ml;cement volume: CPC(2.150±0.191)ml, PMMA(2.150±0.229)ml.Conclusions: It was suggested that the initial intensity and stiffnesswere influenced by BMD, a significant positive correlation. There wassome reference in earlier diagnosis of osteoporosis and in predictionof OVCF(. KP with CPC results in similar mechanical properties comparedwith PMMA, but these biomechanical results have yet to be substantiatedin more studies.更多还原