不同异体皮质骨板桥接股骨缺损的实验研究

[目的]观察冷冻组、酒精组、新鲜组异体皮质骨板桥接兔股骨缺损处的生物力学、影像学及组织学变化的差异。[方法]将制备好的冷冻、酒精储存和新鲜异体皮质骨板分别植入随机分组的3组大白兔股骨缺损处，植入后4、8、12周取材，从生物力学、影像学及组织学方面分析3种异体皮质骨板在兔体内的生物学变化过程。[结果]术后4周冷冻、酒精、新鲜组弯曲应力及位移相近，8、12周前2组较新鲜组有很大差异。术后12周冷冻、酒精组X线片均见异体皮质骨与宿主骨融合一体，新鲜组则未见融合。术后4周冷冻、酒精组出现成骨细胞，新鲜组未见；术后8周冷冻、酒精组有连续排列的成骨细胞，新鲜组仅见少量不连续的成骨细胞；术后12周冷冻、酒精组见大量连续排列的成骨细胞，新鲜组仅见排列连续的成骨细胞。[结论]冷冻、酒精储存异体皮质骨板和新鲜异体皮质骨板均具有初期生物力学的支撑功能；酒精储存异体骨板和冷冻异体骨板均能达到宿主骨-异体骨融合，而新鲜异体骨板由于免疫排斥反应其宿主骨-异体骨愈合能力较差。     

同种异体皮质骨板重建股骨压力侧骨皮质缺损的实验研究

目的 探讨同种异体皮质骨板重建压力侧骨皮质缺损的可行性及效果.方法 24只成年山羊,制作压力侧骨皮质缺损动物模型.随机分两组,实验组12只:行异体骨析、钢板固定结合植骨;对照组12只:仅行钢板固定结合植骨.于术后4、8、12周进行影像学观察,生物力学测试和组织学检查.结果 术后实验组内固定位置均良好,对照组4例发生螺钉松动、钢板断裂等内固定失效现象.12周时实验组髓腔再通,异体皮质骨与宿主骨融合;对照组仍可见不均匀骨痂影.各时间点两组标本的抗扭转、抗压缩刚度比较具有非常显著性差异(P＜0.01).组织学检查按Lane等评分标准评分,有非常显著性差异(P＜0.01).结论 同种异体皮质骨板能够结构性重建骨皮质缺损区,恢复其承载功能,有效防止内固定失败,促进骨折愈合.     

大段异体骨关节移植后长期转归的观察

目的观察大段人异体骨关节移植后的转归。方法取植入４～６５个月的大段异体骨关节标本,采用组织学及ＢＭＰ分子原位杂交及免疫组化方法,结合随访Ｘ线片及骨核素扫描进行研究。结果外骨痂由宿主骨皮质向异体骨皮质侧生长连接愈合,皮质骨爬行替代相当缓慢,５年时仍大量死骨与活骨共存。异体骨骨松质内可见新骨、骨髓及新生血管,但骨小梁有吸收。非主要负重区的关节软骨细胞部分存活。４个月时异体骨皮质浅层及骨痂ＢＭＰ免疫组化染色及分子原位杂交阳性。植入１２个月至６５个月骨皮质浅、深层及活骨ＢＭＰ表达均呈阴性。结论（１）骨痂由自体骨向异体骨侧生长连接以达到骨性愈合。异体骨关节血运可重建。（２）非负重区关节软骨可部分存活。关节塌陷与骨小梁吸收有关。（３）异体骨内ＢＭＰ在移植后早期的新骨替代及愈合中起作用,１２个月后则主要是靠骨传导而不是骨诱导。（４）坏死骨单位的排除不完全,是异体骨皮质新骨替代慢的原因。     

兔冷冻与脱钙冻干异体骨修复骨缺损的比较

[目的]比较冷冻与脱钙冻干异体骨移植物修复兔桡骨缺损的成骨能力和生物力学特性。[方法]制备冷冻和脱钙冻干异体骨移植物,分别植入各16只新西兰白兔的双侧桡骨中段1.5cm缺损处。于术后2、4、8、12周处死动物,行大体观察、X线及HE染色组织学观察评分,形态计量新生骨量;取静脉血检测BGP;术后12周对移植骨段进行生物力学测试。[结果]移植骨大体形态学观察可见各组移植骨位置良好,术后12周均可与宿主骨形成牢固愈合。术后4周和8周,脱钙冻干组的X线评分、组织学评分及成骨计量均显著优于冷冻组(P0.05),但术后12周两组无显著差别(P0.05)。术后4周和8周,脱钙冻干组血浆BGP水平显著高于冷冻组(P0.05);术后12周两组间差异已无统计学意义(P0.05)。术后12周生物力学测试,脱钙冻干组在三点弯曲试验的最大弯曲力和抗压强度,以及扭转试验的最大扭矩和抗扭强度均显著不及冷冻组(P0.05)。[结论]与冷冻骨相比,脱钙冻干异体骨具有优良的成骨活性,但力学强度下降。     

同种异体皮质骨板移植

1　引　言195 1年Kreutz报道用冻干同种异体皮质骨板移植治疗骨折,2 0世纪80年代中期,同种异体皮质骨板移植开始应用于人工关节外科,重建股骨骨溶解和假体周围骨折[1] 。近年来人们对同种异体皮质骨板移植组织学、X线表现、临床应用以及并发症等方面进行了广泛研究,本文就相关文献做一综述。2　同种异体皮质骨板移植的生物学行为用任何方法保存的异体骨移植后必须经受宿主骨的爬行替代而存活。节断性同种异体皮质骨移植的爬行替代沿移植骨长轴进行,骨修复在宿主骨与移植骨交界处最活跃,然后沿长轴向中央发展。长段同种异体皮质骨移植在体内…     

同种异体皮质骨板移植治疗股骨假体周围骨折

目的 评价同种异体皮质骨板移植治疗髋关节股骨假体周围骨折的临床治疗效果。方法 对7例髋关节置换术后股骨假体周围骨折患者应用深低温冷冻和环氧乙烷处理同种异体皮质骨板移植治疗股骨骨折。根据Harris评分,外周血T淋巴细胞亚群、抗体和免疫复合物检测、X线摄片以及核素骨显像评价其治疗效果。结果 患者未发生免疫排斥反应和感染,术后3、6、12、24个月Harris评分分别比术前平均增加21、32、40、40分。术后3个月骨折愈合,一部分移植骨板与宿主骨骨性连接,同位素骨显像骨板移植区放射性分布比对侧浓集。术后12个月,85％移植骨板与宿主骨融为一体,宿主股骨皮质厚度增加3～5mm,平均4．3mm,骨板放射性浓集进一步加深,15％移植骨板出现吸收现象。术后24个月,80％移植骨板重新塑形后恢复宿主股骨皮质骨密度,10％骨板表面吸收停止,股骨假体无松动。结论 深低温冷冻和环氧乙烷处理同种异体皮质骨板移植无菌、抗原性弱、生物相容性好,移植骨板能够维持骨折和假体稳定性,增加股骨局部骨量储备,避免再次手术取出金属内置物,是用来治疗股骨假体周围骨折较理想的方法之一。     

大段同种异体皮质骨移植后哈佛管内的骨诱导成骨研究

目的：研究大段同种异体皮质骨移植过程中哈佛系统的成骨作用，探讨大段同种异体皮质骨愈合活化表面的临床意义，方法：48只新西兰大白兔为实验动，手术移植2cm经深底温处理的大段同种异体皮质骨段，于术后2、4、8、12周取材，观察各组X线片，组织学，BMP免疫组织化学染色，四环素荧光标记变化，记录骨吸收重建情况。结果：骨端愈合率；近端宿主骨－异体骨接全部4周90％，8周100％；远端4周60％，8周90％，12周100％，组织学观察；4周时皮质骨内哈佛管扩大，多位于近骨髓腔处的皮质内；8周时可观察到扩大的哈佛管周围新骨形成；12周时可见到新形成的类哈佛系统。BMP免疫组织化学染色显示移植后4周皮质内扩大的哈佛管壁有弱阳性表达，8周时有强阳性表达，管腔内细胞成分增多，哈佛管周围的骨隐窝内亦有阳性表达，四环素荧光标记显示术后2周可观察到异体骨周边的四环素荧光标记，移植后4周可见较强的荧光标记于哈佛管内，哈佛管内与福克曼管交叉处为强阳性性表达。术后8南呤骨髓腔处的皮质骨陷窝内亦有强的四环素荧光标记。结论：大段同种异体皮质骨通过四个愈合表达进行活化重建；（1）哈佛系统的骨吸收，骨诱导成骨；（2）宿主骨－异体骨接合端的爬行替代；（3）异体皮质骨周围的吸收与重建；（4）骨髓腔内壁的成骨活动，研究提示在临床实践中应尽量保留异体皮质骨的有效成骨活性表面，和各种机械遮挡，采用髓内固定，并应保留适当骨瘤腔的空间，利用皮质骨的血运重建。     

异种脱蛋白皮质骨管复合组织工程骨修复大段骨缺损的实验研究

目的评估异种脱蛋白皮质骨管复合组织工程骨修复大段骨缺损的力学作用及成骨效果。方法 36只成年猪,随机分成3组,实验组植入异种脱蛋白皮质骨管复合骨基质明胶、骨形态发生蛋白及骨膜细胞,对照组植入异种脱蛋白骨皮质骨管复合自体髂骨微粒,空白对照组植入单纯异种脱蛋白骨管,三组均采用锁定钢板及异种皮质骨板固定。通过X线检查、病理组织学、生物力学及灰量测定检查观察骨缺损修复情况。结果术后24周,实验组及对照组骨缺损处新生骨生长良好,骨小梁排列整齐,空白对照组骨缺损新生骨较少,且与断端部分相连。植入后24周实验组与对照组的生物力学及骨矿含量相比无统计学差异,且均明显高于空白对照组。结论异种脱蛋白皮质骨管复合骨基质明胶、骨形态发生蛋白及骨膜细胞修复大段骨缺损具有良好的应力支撑作用,其成骨效果与自体松质骨相当。     

可注射硫酸钙基人工骨在羊股骨缺损植骨中的实验研究

[目的]通过可注射性植骨材料在羊股骨缺损的骨内植入,评价可注射硫酸钙基植骨材料的骨修复能力.[方法]建立绵羊单侧股骨缺损模型,将可注射硫酸钙基人工骨植入骨缺损内,于术后4、8、12周行大体观察及X线片检查缺损区骨痂生长情况.[结果]术后4周时材料大部分降解吸收,可见新生骨小梁结构,缺损区有部分骨痂形成;8周时可见大量新生骨小梁结构,部分形成成熟骨单位,可见骨母细胞,新生骨与宿主骨界面模糊,完成断端间的骨性桥接;12周时材料完全降解,形成的新生骨小梁部分出现重塑形成正常骨结构,缺损区被新骨完全替代,骨痂开始塑形,髓腔再通.[结论]可注射硫酸钙基人工骨作为骨移植替代材料,具有良好的骨传导性和骨诱导性,用于修复骨缺损可以取得良好的效果.     

同种异体皮质骨移植的生物力学研究

目的探讨不同力学环境下同种异体皮质骨的生物力学性能变化。方法以４０只家兔前肢尺骨中段骨移植后造成不同受力状态的动物模型,左前肢承受正常生理载荷,右前肢承受低载荷,对植骨区标本进行三点弯曲破坏载荷、骨密度值、骨孔隙率的测试。结果同种异体皮质骨植入后,移植骨－宿主骨界面间的连接强度持续上升,而移植骨自身的生物力学性能呈较快下降再缓慢上升的趋势;从骨移植后第８周开始,正常载荷侧的移植骨－宿主骨界面间的连接强度明显高于低载荷侧,到第１６周时,正常载荷侧移植骨自身的生物力学强度改善也更为明显。结论同种异体皮质骨植入以后的生物力学性能呈较快下降再缓慢上升的趋势;生理载荷的刺激有利于同种异体皮质骨生物力学性能的恢复与改善     

A biomechanical investigation on the incorporation of cortical allograft in rabbit ulna defects

Objective:To explore the changes of biomechanical properties of cortical allograft in different mechanical environments.Methods:Cortical allograft was transplanted to each side of the midshaft diaphyseal ulna of each one of 40 rabbits.The left transplanted allograft underwent normal physiological load,while the right one underwent lower load.After animals were killed,specimens were taken for examination of bone mineral density,bone porosity and maximal three-point-bend breaking load.Results:The union strength of allograft-host bone junction was increased constantly;meanwhile,the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and a later recovery of its strength.In comparison,the union strength of the normally loaded graft-host bone construct was significantly higher than that of the lower loaded side at the 8th and 16the week after transplantation.At the 16th week,there was greater bone strength in normally loaded graft than that in lower loaded graft.conclusions:The internal repair can lead to initial preater weakening of cortical allograft and later gradual recovery of its strength.The effect of physiological load can accelerate the improvement of the biomechanical properties of allograft.     

Effects of rhBMP-2 on cortical strut allograft healing to the femur in revision total hip arthroplasties: an experimental study

We have studied the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on cortical strut allograft healing and remodelling in revision hip arthroplasty. Thirty adult New Zealand rabbits underwent bilateral onlay allograft strut procedures to the femur using wires. The left femur (experimental side) received the rhBMP-2 device (1.0-mg rhBMP-2/gelatin composites) interposed between the allograft and host bone, while the right side was grafted with an allograft strut as the control. The femurs and implants were retrieved at 4, 6, and 8 weeks postoperatively. The healing of cortical strut grafts to the femur was enhanced dramatically by the addition of the rhBMP-2 device in radiographic examination, contact radiographic examination, non-decalcification sections, fluorescence tag, and computer-aided image analysis. The remodelling of cortical strut allograft was also accelerated. The new bone formation ratio and radiographic scores of the experimental side were also much higher than the control side at all times. Strut healing with the rhBMP-2 device at 4 weeks postoperatively was superior to the healing in control sides at 8 weeks. Our findings showed that the rhBMP-2 device improved and accelerated the course of cortical strut allograft healing and remodelling with host bone.     

Biomechanical effects of processing bulk allograft bone with negative-pressure washing

The best method for processing allograft bone to prevent disease transmission without compromising its biomechanical function is not yet determined. We evaluated the biomechanical effects of processing bulk allograft bone segments with negative-pressure washing. Specimens were prepared from matched pairs of adult cadaveric femurs. The experimental femur underwent routine processing, followed by negative-pressure washing, whereas its matched control underwent routine processing only. Each specimen was tested to failure, and maximal stress values were determined. No differences were found in yield stress comparisons between groups for the following specimens and tests: compression of machined femoral heads, screw push-out testing in cortical bone, and 4-point bending of cortical beams. Compression testing of diaphyseal ring struts provided varied results. Negative-pressure-washed half-ring strut grafts were statistically stronger (9.6%) than their matched controls (P = 0.018). Negative-pressure-washed full-ring strut grafts were statistically less strong (-12.2%) than their control counterparts (P = 0.003). We studied 5 different allograft types (designed with clinically relevant geometries) subjected to 3 modes of testing (representative of loading in typical clinical situations). Our data show that processing of large, essentially intact allograft bone segments with negative-pressure washing had little, if any, biomechanical effect relative to frozen controls.     

Experimental repair of segmental bone defects in rabbits by demineralized allograft covered by free autogenous periosteum

Using an experimental model of segmental bone defect in the ulna of rabbits we investigated the effect on bone healing of fresh cancellous autograft (FCA), demineralized deep-frozen allograft (DDA), and demineralized deep-frozen allograft covered with free autogenous periosteum (DDAwP). Radiologically, it was found that the results of the FCA and DDAwP groups were superior to those of the DDA group. This superiority was statistically significant after the 3rd to the 9th week for the FCA group, and the 6th to the 9th week for the DDAwP group. However, bone formation and union in the DDA group reached the same level of those in the other groups after 12 weeks. When the all histological findings were compared at the 12th week, the FCA and DDAwP groups were statistically superior to the DDA group in terms of proximal union. On distal union, the FCA group was statistically superior to the DDA group. Biomechanically, the FCA and DDAwP groups were statistically superior to the DDA group in terms of maximum torque and energy absorption. The DDAwP group was superior to the DDA group in term of stiffness. We conclude that ossification could be more easily achieved if demineralized deep-frozen allograft is covered with periosteum when faced with the need for quicker and better quality bone integration.     

异体皮质骨板不同固定方式的生物力学比较

目的探讨异体皮质骨板采用不同固定方式的强度差异及机制。方法由南华大学解剖室提供的14具(男8具,女6具)尸体上取下股骨27根,X线排除骨病后,用游标卡尺测量,取各骨最细部分的直径,制作27个不稳定骨折模型,随机分成A、B、C组,每组9个,分别采用3种方式固定:A组:用2块大小为110mm×10mm×3mm异体皮质骨板嵌合固定;B组:用2块110mm×10mm×3mm异体皮质骨板和5枚骨螺钉固定;C组:用1块110mm×10mm×3mm骨板和5枚骨螺钉固定。分别进行生物力学实验,测试其压缩、弯曲及扭转刚度和极限载荷。结果不同固定方式显示不同的力学特征。A组的轴向刚度与B组相似,且高于C组,但抗弯和扭转刚度显著高于B、C两组,差异有统计学意义(P<0.05)。A组的压缩、弯曲、扭转极限载荷分别为1.65±0.34kN,554.33±49.34N,7.78±0.82Nm;B组分别为1.12±0.37kN,428.00±37.40N,3.39±0.22Nm,两组比较有统计学意义(P<0.05),而C组分别为0.71±0.46kN,218.67±36.53N,1.74±0.12Nm,与A组比较差异有统计学意义(P<0.01)。结论异体皮质骨板固定的强度与固定方式有关。双板嵌合固定比骨板骨螺钉固定具有更大的强度和刚度,可满足临床需要。     

Effect of allograft compound vertebra on vertebral reconstruction in rabbits

Objective ： To study the effect of allograft compound vertebra on vertebral reconstruction in rabbits so as to provide biomechanical direction for manufacturing and selecting vertebral reconstruction materials. Methods： Twenty-five healthy New Zealand white rabbits were divided randomly into three groups： normal group （ Group A, n = 5 ） ,iliac bone graft group （ Group B, n = 10） and allograft compound vertebra group （ Group C, n = 10）. After C4 was resected, iliac bone implantation and allograft bone cage transplantation were fulfilled in Group B and Group C, respectively. Every 5 rabbits from Group B and Group C were selected to test the biomechanical strength and biological activity one and two months postoperatively. Results： No significant statistical difference was found between Group A and Group C one and two monthspostoperatively （ P 〉 0.05 ）. The biomechanical strength of Group B was much weaker than that of Group A and Group C one month postoperatively （P 〈 0.05 ）, but at two months postoperatively, no statistical difference was found among the three groups. The biological activity and vertebral moulding ability of Group C were better than those of Group B at one and two months postoperatively. Conclusions： Compound vertebra, which is made up of allograft cortical bone cage and autogenous cancellous bone, shows instantaneous and permanent biomechanical stability and biological activity, therefore, it is an ideal material for vertebral reconstruction.     

Experimental study on the repair of tibial plateau defect

Objective: To evaluate the effect of autograft bone,allograft bone,calcium sulfate bone cement,and calcium phosphate bone cement on the repair of tibial plateau defect in rabbits.Methods: We used autog...     

Endosteal substitution with an allograft cortical strut in the treatment of a periprosthetic femur fracture: a case report

The use of allograft cortical struts in the treatment of periprosthetic fractures of the femur has been well described. Allograft struts are used to supplement cerclage wire fixation or may be placed outside the cortex opposite plate and screw fixation to improve screw fixation in osteoporotic bone. This generally requires extensive soft tissue stripping and may lead to delayed bony union. A technique is described wherein an allograft strut was inserted into the medullary canal through the fracture site and used as an endosteal substitution for osteoporotic cortical bone. This technique can improve screw fixation in osteoporotic bone while avoiding devascularization of the fractured femur.