磷酸钙骨水泥强化骨质疏松绵羊腰椎力学强度的动态观察

目的观察磷酸钙骨水泥（calcium phosphate cement,CPC）强化骨质疏松绵羊腰椎生物力学强度的体内动态变化。方法成年雌性绵羊12只行去势手术后饲养1年,测量去势前后腰椎骨密度。取L2~L5为实验对象,空白组不给予任何处理,CPC组中,经椎弓根向椎体内注射CPC 2.0 mL。于术后1 d、6周、12周和24周四个时间点各随机处死3只绵羊,对椎体行压缩实验,分别测量各组中椎体的最大压缩应力（ultimate compressive stress,σult）和能量吸收值（energy absorption value,EAV）,对比分析同一时间点不同方法之间和同一方法的不同时间点之间的力学指标。结果去势1年后绵羊腰椎骨密度显著下降,差异具有统计学意义（P〈0.05）,骨质疏松绵羊模型建立成功。空白组中各时间点之间的σult和EAV均无显著性差异（P〉0.05）,而CPC组中各时间点之间的σult和EAV也均无显著性差异（P〉0.05）;在同一时间点,CPC组螺钉的σult和EAV均显著高于对照组（P〈0.05）。结论 CPC对骨质疏松椎体的即时强度和远期强度均有显著的强化效果,它对椎体的强化效果在体内是动态稳定的,为脊柱达到坚强骨性融合提供了良好的力学环境。CPC作为一种生物相容性好、可降解吸收、可促骨生成和机械强度好的材料具有广阔临床应用前景。     

硫酸钙骨水泥强化去势绵羊体内椎弓根螺钉稳定性的动态生物力学研究

目的评价硫酸钙骨水泥(calciumsulfate cement,CSC)在去势绵羊体内强化椎弓根螺钉稳定性的动态效果。方法12只成年雌性绵羊行去势手术1年后,并测量去势前后腰椎骨密度。取去势绵羊的L2～L5双侧椎弓根为实验对象,其中一侧直接拧入椎弓根螺钉(空白组),另一侧向钉道内注入CSC(0.5ml)后,再拧入椎弓根螺钉(CSC组),两种方法左右完全随机。于术后1天,6周,12周,24周四个时间点各随机处死3只绵羊,分别测定各组中螺钉的轴向拔出力和拔出能量吸收值,对比分析同一时间点不同方法之间和同一方法的不同时间点之间的力学指标。结果去势1年后绵羊腰椎骨密度显著下降,差异具有统计学意义(P0.05),骨质疏松绵羊模型建立成功。空白组中各时间点之间的最大轴向拔出力(Fmax)和拔出能量吸收值(E)无显著性差异(P0.05),而CSC组中24周螺钉的Fmax和E显著高于同组的1天,6周和12周;同一时间点,CSC组螺钉的Fmax和E均显著高于对照组(P0.05)。结论CSC可以显著提高骨质疏松椎体内椎弓根螺钉的稳定性,强化螺钉的作用在体内是动态稳定的,并能进一步提高螺钉在体内的远期稳定性。在椎弓根螺钉强化方面,CSC可以作为PMMA的替代材料。     

硫酸钙骨水泥强化椎弓根螺钉稳定性的体内实验研究

目的:评价硫酸钙骨水泥(calcium sulfate cement,CSC)在动物体内强化椎弓根螺钉稳定性的效果,观察钉道界面及材料吸收的情况.方法:4只健康成年山羊,L2～L5每个椎体的一侧椎弓根直接拧入螺钉(空白组),另一侧填充CSC后拧人螺钉(实验组).3个月后处死山羊,随机选择6个椎体(12个螺钉),对其两侧钉道进行显微CT扫描、骨计量学分析和组织学观察;其余10个椎体(20个螺钉)进行轴向拔出试验.结果:显微CT三维重建及骨计量学分析显示实验组钉道周围骨小梁数量及密度明显优于空白组,差异有统计学意义(P<0.05);组织学观察示实验组钉道周围CSC绝大部分已经降解吸收,大量新生骨组织紧密包裹螺钉,形成良好的钉骨结合,界面明显优于空白组,螺钉周围骨小梁明显较空白组致密,仅有少量骨髓腔内仍可见残留的未降解材料;实验组的最大轴向拔出力为914.80±162.88N,能量吸收值1.752±0.214J,空白组为682.50±112.15N和1.437±0.173J,两组间差异均有统计学意义(P<0.05).结论:CSC可以显著增强动物体内椎弓根螺钉的固定强度;随着CSC的降解吸收,大量新骨生成并紧密包绕螺钉,形成良好的钉骨结合,为螺钉在体内的远期稳定性提供了良好的骨质条件.     

硫酸钙骨水泥在骨折椎体成形术中的力学性能

目的评价硫酸钙骨水泥在胸腰椎压缩性骨折椎体成形术中的生物力学性能。方法采集15具新鲜成年小牛胸腰椎标本,制成T11~L1脊柱功能单位,随机分为A、B、C三组各5具,正常完整标本组（A组）,后路复位椎弓根钉固定组（B组）,后路复位椎弓根钉固定结合硫酸钙椎体成形组（C组）。B、C组标本制成T12椎体屈曲压缩性骨折模型,分别采用后路复位椎弓根钉固定及后路复位椎弓根钉固定结合硫酸钙椎体成形。三组标本在WE-10型万能材料试验机上加载不同级别载荷,检测脊柱功能单位的载荷-应变关系、载荷-位移关系、强度、刚度等生物力学性能,试验数据进行统计学处理,并进行组间比较。结果胸腰椎功能单位抗压强度,A、B、C三组分别为（2488±224）N、（3 368±310）N、（4 283±404）N,B、C之间相差21%,差异有统计学意义（t=1.422,P〈0.05）;A、C之间相差42%,差异有统计学意义（t=1.814,P〈0.05）。胸腰椎功能单位刚度,A、B、C三组分别为（400±32）N/mm、（455±42）N/mm、（638±61）N/mm,B、C之间相差29%,差异有统计学意义（t=1.792,P〈0.05）;A、C之间相差37%,差异有统计学意义（t=2.628,P〈0.05）。结论经后路椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学性能优越,术后不但强度大、刚度高,而且承载能力大,椎体高度恢复满意;术后的胸腰椎稳定,极大地分担内固定物的应力负荷,进而降低螺钉的松动、折断发生率及术后椎体高度的丢失。     

不同形态的骨水泥行椎体成形术治疗骨质疏松性胸腰椎压缩骨折的临床观察

目的比较高黏度骨水泥椎体成形术(PVP)与低黏度骨水泥椎体后凸成形术(PKP)在骨质疏松性胸腰椎压缩骨折的疗效。方法:选取于我院就诊的骨质疏松性胸腰椎压缩骨折患者98例,随机分为A、B两组各49例,A组:采用高黏度PVP技术治疗;B组:采用低黏度PKP技术治疗。所有患者术后随访6个月。比较两组患者的住院费用、透视时间、术后3d的Cobb角、oswestry功能不良指数、模拟疼痛量表评分、恢复的椎体高度及术后并发症的发生率。结果与B组相比,A组的透视时间、医疗费用及骨水泥用量显著降低,差异具有统计学意义(P0.05)组内比较,治疗后两组患者的VAS评分、Cobb角及ODI均较治疗前显著改善,差异具有统计学意义(P0.05)。结论:高黏度PVP与低黏度PKP技术在骨质疏松性胸腰椎压缩骨折的疗效相当,并发症发生率相似,但高黏度骨水泥椎体成形术消耗的透视时间更少、医疗费用更低。     

geneX骨水泥强化骨质疏松椎体椎弓根钉的生物力学研究

目的评估骨质疏松情况下geneX骨水泥强化椎弓根钉的固定强度。方法应用微量注射泵对30个新鲜小牛腰椎标本注射稀盐酸建立骨质疏松椎体模型。60个椎弓根分为四组:geneX骨水泥组,硫酸钙骨水泥(CSC)组,聚甲基丙烯酸甲酯骨水泥(PMMA)组,对照组。随机选择一侧注射2.5 ml骨水泥,然后置入螺钉;另一侧行正常螺钉固定对照,应用材料试验机进行轴向拔出力测试,记录各组的轴向最大拔出力和能量吸收值并进行比较。结果 geneX组与CSC组两组拔出力及能量吸收值比较,差异无统计学意义(P>0.05),两组均显著低于PMMA组(P<0.05),两组均显著高于对照组(P<0.05)。结论 geneX骨水泥强化椎弓根钉可显著提高椎弓根固定强度,geneX骨水泥可用作椎弓根强化螺钉的填充材料。     

rhBMP-2/CPC强化骨质疏松椎体力学强度的实验研究

目的观察人重组骨形态发生蛋白-2复合磷酸钙骨水泥(recombinant human bonemorphogenetic protein-2/calcium phosphate cement,rhBMP-2/CPC)强化骨质疏松绵羊腰椎生物力学强度的动态效果。方法成年雌性绵羊12只行去势手术后饲养1年,测量去势前后腰椎骨密度。取L1-L6为实验对象,空白组不给予任何处理;CPC组中,经椎弓根向椎体内注射CPC(2.0 ml);rhBMP-2/CPC组中,经椎弓根向椎体内注射rhBMP-2/CPC(2.0 ml)。于术后1天、6周、12周和24周四个时间点各随机处死3只绵羊,对椎体行压缩实验,分别测量各组中椎体的最大压缩应力(σult)和能量吸收值(EAV),对比分析同一时间点不同方法之间和同一方法的不同时间点之间的力学指标。结果去势1年后绵羊腰椎骨密度显著下降,差异有显著性(P<0.05),骨质疏松绵羊模型建立成功。在术后各时间点,CPC组和rhBMP-2/CPC组的σult和EAV均显著高于空白组(P<0.05);术后1天、6周和12周,rhBMP-2/CPC组和CPC组之间的差异无统计学意义(P>0.05),而rhBMP-2/CPC组中24周的σult显著高于CPC组(P<0.05)。空白组和CPC组中σult各时间点之间的差异均无显著性(P>0.05),而rhBMP-2/CPC组中24周的σult显著高于该组其他三个时间点(P<0.05)。结论 rhBMP-2/CPC不仅能提高骨质疏松椎体的即时强度,还能很好的维持椎体的动态力学强度和进一步提高椎体的远期强度,为脊柱达到坚强骨性融合提供了良好的力学环境。     

骨水泥强化椎弓根螺钉在腰椎滑脱伴骨质疏松椎体中的临床应用

目的 探讨骨水泥强化椎弓根螺钉在腰椎滑脱伴骨质疏松患者的手术方法和疗效.方法 2008年7月至2010年11月年期间收治腰椎滑脱伴骨质疏松患者12例,平均68岁.骨质疏松按Jikei分级Ⅱ级4例,Ⅲ级8例.所有患者行经椎弓根螺钉内固定,术中采用骨水泥强化提高螺钉稳定性,植入椎弓根螺钉共26枚,观察椎弓根螺钉术中及术后的稳定性.结果 患者未发生手术并发症,腰腿痛症状改善明显,术后VAS评分较术前比较改善明显.12例患者均获得随访,随访时间8-16个月,平均14个月.12例均获得骨性融合,X线片显示内固定无松动、断裂或脱落,螺钉周围未见透亮线出现.结论 经椎弓根骨水泥强化椎弓根螺钉,固化椎体的同时增加了椎弓根螺钉界面把持力,能够满足腰椎滑脱伴骨质疏松患者脊椎后路固定手术对力学稳定的要求.     

丙烯酸类骨水泥混合硫酸钙联合经皮椎体后凸成形术治疗骨质疏松性骨折

目的:探究丙烯酸类骨水泥(polymethyl methacrylate,PMMA)混合硫酸钙联合经皮椎体后凸成形术(percutanouskyphoplasty,PKP)治疗骨质疏松性骨折(osteoprosis vertebral compression fracture,OVCF)的临床疗效。方法:对2020年1月至2021年3月收治的191例采用PKP术式治疗的OVCF患者的临床资料进行回顾性分析,其中82例共94个椎体应用PMMA混合硫酸钙进行治疗,设为观察组;109例共125个椎体应用单纯PMMA进行治疗,设为对照组。观察组男16例,女66例,年龄(75.35±11.22)岁,包括36个胸椎,58个腰椎;对照组男22例,女87例,年龄(74.51±9.21)岁,包括63个胸椎,62个腰椎。通过统计两组患者的手术时间、出血量、骨水泥注入量,术前及术后1 d、3个月、1年的疼痛视觉模拟评分(visual analogue scale,VAS)、Oswestry功能障碍指数(Oswestry disability index,ODI)、Cobb角、椎体高度以及术后骨水泥渗漏的发生...     

胸腰椎骨质疏松性骨折自固化磷酸钙骨水泥椎体成形的实验研究

目的探讨自固化磷酸钙骨水泥(calciumphosphatecement,CPC)注射椎体成形术后对胸腰椎骨质疏松性骨折椎体的力学影响。方法自愿捐赠的4具甲醛固定的老年尸体,取胸腰椎骨质疏松标本,平均年龄69岁,男、女各2具。每具标本随机取6个椎体,制备24个单椎体标本,建立前屈方向加载单椎体骨折模型。将CPC粉末与固化液以2.5g∶1ml调和制备CPC骨水泥,对骨折标本行CPC成形强化,每个椎体注射CPC约4ml。分别进行骨折前、成形后屈曲压缩力学检测。结果骨质疏松椎体标本骨折前最大载荷为1954±46N,位移长度为5.60±0.70mm,刚度为349±18N/mm;骨折间隙CPC填塞成形后最大载荷为2285±34N,位移为5.35±0.60mm,刚度为427±10N/mm,各指标骨折前和成形后比较差异均有统计学意义(P<0.05)。CPC加强成形后单椎体的承载能力强度较骨折前提高16.92%,刚度较骨折前提高22.31%。结论椎体内注射CPC能明显恢复骨质疏松骨折椎体的力学性能。     

Enhancement of pedicle screw stability using calcium phosphate cement in osteoporotic vertebrae: in vivo biomechanical study

 We conducted an experimental study using female beagles with and without ovariectomy-induced osteoporosis to determine the effect of calcium phosphate cement (CPC) on the mechanical stability of inserted pedicle screws. A drill hole was created from the base of the transverse process to the vertebral body; CPC was injected into the hole, and then a screw was inserted into the same hole. In the presence of osteoporosis evidenced by dual X-ray absorptiometry, the stability of the inserted screw augmented by CPC against pull-out and cephalocaudal forces were significantly greater by 28% and 54% at 1 week after operation, 48% and 71% at 2 weeks, and 56% and 68% at 4 weeks compared with those without CPC. The pull-out strength increased progressively with time after surgery, probably reflecting new-bone growth from the surrounding cancellous bone, which was in direct contact with the CPC, as shown in the histologic study. At each time point the cephalocaudal rigidity was similar and the pull-out strength greater than that for the screws inserted without CPC in nonporotic dogs. These findings suggest that CPC augments the stability of the inserted pedicle screws and increases the stiffness of fixed osteoporotic motion segments using instrumentation. Received: September 9, 2002 / Accepted: January 6, 2003 RID="*" ID="*" Offprint requests to: Y. Taniwaki     

胸腰椎骨质疏松骨折行磷酸钙骨水泥灌注成形的生物力学实验

目的:探讨磷酸钙骨水泥(CPC)注射椎体成形术后对胸腰椎骨质疏松骨折椎体的力学影响。方法:将4具甲醛固定的老年尸体胸腰椎标本建立前屈方向加载单椎体骨折模型,将固液比为2.5∶1的自固化CPC对胸腰椎骨质疏松骨折标本行成形强化,骨折前、成形后分别行屈曲压缩力学实验。结果:在同样的载荷下,单椎体CPC成形后的椎体应变比骨折前小,有统计学差异(t=6.37,P<0.05),骨质疏松性胸腰椎标本行CPC灌注成形可以恢复椎体的强度和刚度,分别增加16.92%和22.31%(P<0.05)。结论:椎体内注射CPC能明显恢复骨质疏松骨折椎体的力学性质。     

椎弓根融合器添加磷酸钙骨水泥后的生物力学效果

目的:评价磷酸钙骨水泥(calcium phosphate cement,CPC)强化和修复椎弓根融合器的生物力学效果。方法:8具成人新鲜腰椎骨L1-L4共32个椎体,随机选取其中20个,分为3组(A,B,C),每组10个。A组(对照组):随机选择10个椎体双侧椎弓根放置直径为6.5 mm的椎弓根融合器,不穿透椎体前侧骨皮质。在材料实验机上进行椎弓根融合器最大轴向拔出力(Fmax)实验,拔出速率为5 mm/min。B组(修复组):对照组拔出椎弓根融合器后再向椎弓根融合器中空部分注入配制好CPC 3-5 ml,室温(28℃)1 h后再行前述最大轴向拔出力(Fmax)实验。C组(强化组):另选10个椎体直接向椎弓根融合器中空部分注入配制好CPC和拧入椎弓根融合器,再行拔出实验。沿椎弓根融合器方向锯开标本,观察CPC在椎体中分布范围。另外10个椎体作椎弓根融合器的递增负荷的周期抗屈实验。结果:正常对照组椎弓根融合器Fmax为(843.1±132.2)N,修复组为(1456.2±239.9)N,强化组为(1499.5±241.2)N;向椎弓根融合器中空部分注入CPC,未见CPC溢出椎弓根外或椎管内。周期抗屈实验中,添加CPC可使椎弓根融合器耐受更大的负荷或在同等负荷下仅产生较小的位移。CPC骨水泥强化和修复椎弓根融合器后轴向拔出力明显高于强化前,差异具有显著性意义(P<0.05)。结论:沿椎弓根融合器中空部分注入CPC可显著增加椎弓根螺钉的稳定性,并能减少CPC向椎弓根外或椎管内溢出。在活体中即使不添加CPC也有利于骨细胞长入椎弓根融合器侧孔,同样可以增加螺钉的稳定性。适用于螺钉松动和拔出的修复固定。     

医用硫酸钙在家兔腰椎融合模型中的成骨能力

[目的]通过与自体髂骨进行比较,评价医用硫酸钙单独应用的成骨能力,并探讨其可能的成骨机理。[方法]建立家兔腰椎后外侧融合模型,以自身作为对照,双侧横突间植骨,左侧植入硫酸钙颗粒,右侧植入自体髂骨。于术后3、6、12周行X线、CT及组织学检查。[结果]术后3周,硫酸钙尚可见残留颗粒,自体骨完全降解;植骨区域内均可见到大量的破骨细胞,并有血管纤维组织长入。术后6周,硫酸钙完全降解,影像学检查两者之间没有明显的差异,表现为局部骨密度增高,新骨成形;组织学检查两侧植骨区内均为大量的透明软骨形成,自体髂骨植骨区内可见散在的骨小梁结构。术后12周,组织学及影像学上二者没有任何的差别,两侧形成的骨组织与家兔的椎体骨组织结构相同。[结论]医用硫酸钙作为骨移植替代材料,除了具有良好的骨传导性外,硫酸钙可能还具有骨诱导性,其成骨能力与自体髂骨相当,医用硫酸钙单独应用可以取得良好的融合效果。     

椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学研究

目的探讨椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学性能。方法15具新鲜雄性小牛胸腰椎标本制成11～L1脊柱功能单位,随机分为正常完整标本组（A组）、后路经椎弓根螺钉内固定组（B组）、椎弓根螺钉内固定结合硫酸钙椎体成形术组（C组）。3组标本在万能材料试验机上测试其生物力学性能,试验数据进行统计学处理,并进行组间比较。结果C组的椎体和椎间盘平均应变比B组低14％和12％,比A组低21％和13％;C组位移分别比B、A组减少25％和37％。胸腰椎椎体和椎间盘的强度：C组比B组高14％和24％,比A组高13％和20％;C组胸腰椎刚度比B、A分别高44％和53％。胸腰椎最大抗扭强度：C组分别比B、A组高18％和30％,扭转刚度C组分别比B、A组高30％和46％。以上数据经统计学处理,差异均有统计学意义（P〈0．05）。结论椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学性能是优越的,不但强度、刚度大,而且术后的胸腰椎体稳定,有利于减轻内植物的应力负荷,进而降低螺钉的松动、折断发生率及术后椎体高度的丢失。     

Biomechanical evaluation of a new augmentation method for enhanced screw fixation in osteoporotic proximal femoral fractures.

A biomechanical investigation on eight pairs of human cadaver proximal femurs was performed to evaluate the impact of a new augmentation method on the internal fixation of osteoporotic proximal femur fractures. The study focused on enhancing implant purchase to reduce the incidence of implant cut-out in osteoporotic bone. In a left-right comparison, a conventional hip screw fixation (control) was compared to the new cement augmentation method. After bone bed preparation through high pressure irrigation to remove fat, blood, and bone debris, the bones were augmented with low viscosity polymethylmethacrylate (PMMA) cement. Step-wise fatigue testing was performed by cyclically loading the femoral heads in a physiological manner, beginning at 1,500 N and increasing 500 N every 5,000 cycles to 4,000 N, and continuously monitoring head displacement. Failure was defined as >5.0 mm head displacement. The head displacement at 2,000 N was significantly smaller (p=0.018) for the augmented group as compared to the conventionally treated bones (0.09+/-0.01 mm vs. 0.90+/-0.32 mm; mean+/-SEM). The displacement rate at the second load step was significantly higher (p=0.018) for the conventionally treated bones as compared to the augmented ones. All of the nonaugmented specimens failed during testing, where 50% of the augmented specimens did not fail. The promising results of these experiments suggest that this new standardized irrigation/augmentation method enhances the implant anchorage and offers a potential solution to the problem of implant cut-out in osteoporotic metaphyseal bone.     

Biomechanical evaluation of kyphoplasty with calcium sulfate cement in a cadaveric osteoporotic vertebral compression fracture model.

BACKGROUND CONTEXT: Vertebral compression fractures can cause deformity, pain, and disability. Kyphoplasty involves percutaneous insertion of an inflatable balloon tamp into a fractured vertebra followed by injection of polymethylmethacrylate (PMMA) bone cement. PMMA has several disadvantages such as potential thermal necrosis and monomer toxicity. Calcium sulfate cement (CSC) is nontoxic, osteoconductive, and bioabsorbable. PURPOSE: To evaluate the biomechanical performance of CSC for kyphoplasty in cadaveric osteoporotic vertebral bodies. STUDY DESIGN: Destructive biomechanical tests using fresh cadaveric thoracolumbar vertebral bodies. METHODS: Thirty-three vertebral bodies (T9 to L4) from osteoporotic cadaveric spines were disarticulated, stripped of soft tissue, and measured for height and volume. Each vertebral body was compressed at 0.5 mm/s using a hinged plating system on a materials testing machine to create an anterior wedge fracture and reduce the anterior height by 25%. Pretreatment strength and stiffness were measured. Two KyphX inflatable balloon tamps were used to reexpand each vertebral body. After randomization, three groups were created: Group A-no cement; Group B-PMMA; Group C-calcium sulfate cement. Groups B and C were filled with the corresponding cement to 25% of the vertebral body volume. All vertebral bodies were then recompressed by 25% of the post-kyphoplasty anterior height to obtain posttreatment strength and stiffness. RESULTS: Treatment with PMMA restored vertebral strength to 127% of the intact level (4168.2 N+/-2288.7) and stiffness to 70% of the intact level (810.0 N/mm+/-380.6). Treatment with CSC restored strength to 108% of the intact level (3429.6 N+/-2440.7) and stiffness to 46% of the intact level (597.7 N/mm+/-317.5). CSC and PMMA were not significantly different for strength restoration (p=.4). Significantly greater strength restoration was obtained with either PMMA or CSC, compared with the control group (p=.003 and .03, respectively). Stiffness restoration tended to be greater with PMMA than for CSC, but this difference was not statistically significant (p=.1). Both cements had significantly greater stiffness when compared with the control group (p=.001 and p=.04, respectively). CONCLUSIONS: Use of CSC for kyphoplasty yields similar vertebral body strength and stiffness as compared with PMMA. It may be a useful alternative bone cement for kyphoplasty. Further studies are required to assess the bioabsorption of CSCs after kyphoplasty in vivo.