经诱导的大鼠成肌细胞应用于组织工程化人工骨的实验研究

[目的]探讨骨形态发生蛋白诱导的大鼠成肌细胞应用于组织工程化人工骨修复大鼠胫骨缺损的效果。[方法]32只体重在200~250 g的雄性SD大鼠随机分成4组,每组8只。A组:聚乙烯管内植入诱导2周的成肌细胞复合透明质酸钠。B组:聚乙烯管内植入成肌细胞复合透明质酸钠。C组:聚乙烯管内植入透明质酸钠。D组:聚乙烯管内注入生理盐水。术后12周,进行X线观察、大体观察、组织学观察(HE染色)以及四环素和钙黄绿素标记。[结果]术后12周时大体观察发现,A、B组骨缺损处可见大量类骨样组织填充,未触及反常活动,C、D组可见少量胶冻样组织及类骨样组织填充,无反常活动。X线观察可见A和B组骨痂吸收,髓腔再通,C、D组有少量新骨痂,髓腔未通。组织学观察可见A和B组有大量新生骨小梁,四环素和钙黄绿素染色可见黄绿色荧光。[结论]初步结果显示经诱导的大鼠成肌细胞可作为骨组织工程的种子细胞,用于修复骨缺损。     

聚磷酸钙纤维/磷酸钙骨水泥/微小颗粒骨修复骨缺损的实验研究

目的探讨聚磷酸钙纤维(calcium polyphosphate fibers,CPPF)、磷酸钙骨水泥(calcium phosphate cement,CPC)、自体微小颗粒骨复合材料修复骨缺损的能力。方法选用新西兰大白兔72只,双侧桡骨制成1.5cm骨缺损模型,随机分成6组分别植入。A组:CPPF/CPC/微小颗粒骨复合材料;B组:CPC/微小颗粒骨复合材料;C组:单纯微小颗粒骨;D组:CPPF/CPC复合材料;E组:单纯CPC;F组:空白对照组,不植入任何物质。在2、4、8、12周各时相点,分别进行大体观察、X线照片、组织学切片、扫描电镜观察及力学测试。结果A组在12周可使骨缺损修复,在骨缺损修复各时期,其成骨速度及成骨量均好于其他各组。结论CPPF/CPC/微小颗粒骨复合材料有良好的成骨能力、力学特性和生物相容性,有望成为骨组织工程中修复骨缺损的理想材料。     

自体微小颗粒骨复合肝细胞生长因子（HGF)修复骨缺损的实验研究

目的探讨自体微小颗粒骨复合肝细胞生长因子(hepatocyte growth factor,HGF)修复骨缺损的效果,以找到一种新的促进骨愈合的方法。方法将30只新西兰大耳白兔双侧桡骨中段制成骨缺损模型,分别植入自体微小颗粒骨、HGF和自体微小颗粒骨与HGF的复合物,同时设空白对照组,分别手术后第4、8周进行大体观察、X线检查及组织学检查,术后第8周进行压缩试验,比较修复骨缺损的疗效。结果经大体观察、组织学及X线检查发现,术后第8周自体微小颗粒骨复合HGF能更有效地修复节段性骨缺损,对照组无骨愈合迹象。结论自体微小颗粒骨复合HGF具有优良的修复骨缺损(包括因骨质疏松所致的骨皮质空洞)的能力,为骨缺损修复提供了一种新方法。     

复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙人工骨结合带血供骨膜修复羊大段骨缺损

目的 研究复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙(PLGA-TCP-BMP-2)人工骨结合自体带血供尺骨骨膜移植修复大段骨缺损的效果. 方法 手术造成30 mm绵羊桡骨骨缺损,A组植入PLGA-TCP-BMP-2人工骨及带血运的尺骨骨膜,B组仅植入PLGA-TCP-BMP-2人工骨,C组不植入任何材料.3组均以钢板固定骨缺损区.术后24周拍摄X线片并处死动物,进行组织学观察评价. 结果 X线检查示A组桡骨缺损处完全成骨修复,皮质骨与髓腔的轮廓清晰;B组亦完全修复,但新生骨密度及髓腔轮廓清晰度均不如A组;C组无有效骨痂形成.组织学检查示A、B组骨痂外层形成为板层骨,C组缺损区可见大量纤维组织填充. 结论 PLGA-TCP-BMP-2人工骨结合自体带血供尺骨骨膜移植能够很好的修复绵羊桡骨30 mm的骨缺损.     

复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙人工骨结合带血供组织修复羊大段骨缺损的试验研究

目的研究复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙(PLGA-TCP-BMP-2)人工骨结合尺骨骨膜及长段自体骨移植修复大段骨缺损的效果。方法手术造成30 mm绵羊桡骨骨缺损,A组植入人工骨及带血运的长段尺骨,B组植入人工骨及带血运的尺骨骨膜,C组仅植入人工骨,D组不植入任何材料。四组均以钢板固定桡骨缺损区。术后行X线摄片,24周处死行CT及组织学检查,进行系统评价。结果 X线检查示术后放射学评分A组高于其它各组。组织学结果显示,A组新生骨完全修复骨缺损区;B组新生骨与断端皮质骨融合,新生骨痂较为纤细;C组新生板层骨及骨陷窝排列较为紊乱;D组无骨连接表现。A、B、C组均未见人工骨材料残留。A组组织学评分最高,D组最低,差异有显著性。结论PLGA-TCP-BMP-2人工骨结合长段自体骨或带血供尺骨骨膜移植能够很好的修复绵羊桡骨大段骨缺损。     

组织工程骨修复山羊胫骨节段性缺损的实验研究

目的应用自体骨髓基质干细胞（BMSCs）复合β-磷酸三钙（β-TCP）构建组织工程化骨，修复山羊胫骨节段性缺损。方法体外扩增培养、成骨诱导山羊BMSCs。实验组将第2代细胞复合β-TCP后修复山羊自体右侧胫骨26mm的节段性缺损（n=8），对照组以单纯β-TCP材料植入骨缺损处（n=8），旷置组（n=2）。术后16、32周分别通过大体形态观察、影像学、组织学和生物力学的方法检测骨缺损的修复效果。结果旷置组术后32周骨缺损未修复，表明动物模型确实可靠。大体观察、X线片和MicroCT显示16周时实验组已有新骨形成，β-TCP材料降解吸收；对照组则只形成少量骨痂，材料无明显降解。组织学检测示实验组有大量幼稚编织骨生成，对照组为纤维结缔组织，并有大量材料残余。实验组骨密度和力学强度低于正常胫骨组（P〈0．05），但明显高于对照组（P〈0．01）。术后32周时大体观察X线片和MicroCT显示术后实验组骨愈合良好，对照组为骨不连；骨密度检测示实验组明显高于对照组（P〈0．05），且与正常胫骨组差异无统计学意义（P〉0．05）。组织学检测示实验组呈骨性愈合，有较多成熟骨组织，对照组为纤维连接。生物力学测试实验组与正常胫骨力学强度差异无统计学意义（P〉0．05）。结论成骨诱导的自体BMSCs复合β-TCP形成的组织工程骨可良好修复山羊胫骨节段性缺损。     

骨髓基质干细胞与生物衍生骨复合修复山羊胫骨缺损的影像学研究

目的探讨骨髓基质干细胞(MSCs)与生物衍生骨复合修复山羊胫骨的长段骨-骨膜缺损,以及修复负重骨缺损的可行性. 方法将18只12月龄健康杂种青山羊(雌雄不限),制备成双侧胫骨中段20 mm骨-骨膜缺损模型,常规钢板螺钉固定;MSCs与生物衍生骨于体外复合培养;对同一只山羊将复合物植入右侧胫骨缺损处作为实验组,以单纯材料植入左侧胫骨缺损处作为对照组,空白组不植入任何材料;在8、12、16和24周各时间点分别行标本的大体观察、X线片观察和骨密度测试,比较其修复骨缺损的能力. 结果大体观察、X线片和骨密度测试显示:实验组8周骨缺损部分修复,12、16周骨缺损完全修复,8、12和16周其骨密度较对照组高,差异有统计学意义(P＜0.05);24周实验组与对照组骨密度差异无统计学意义;空白组骨缺损未修复. 结论组织工程骨早期修复骨缺损能力较强,且较单纯材料成骨量大、迅速,能够对负重骨缺损进行有效的修复.     

低温保存的组织工程骨修复骨缺损的实验研究

目的探讨低温保存的组织工程骨修复骨缺损的能力及低温保存的可行性。方法将人源性生物衍生骨材料复合成骨细胞构建的组织工程骨,在4℃和-196℃的温度环境中保存3个月和6个月,同时以未行低温保存的组织工程骨和生物衍生骨材料作为对照,分别修复实验兔桡骨的长段骨缺损。80只成年日本大耳白兔,随机分为4个实验组(左前肢植入材料):A3组:组织工程骨在4℃保存3个月;A6组:组织工程骨在4℃保存6个月;B3组:组织工程骨在-196℃保存3个月;B6组:组织工程骨在-196℃保存6个月。2个对照组(右前肢植入材料):C组:组织工程骨未行低温保存;D组:单纯生物衍生骨材料。于术后2、4、6和12周行大体和组织学观察,并于6周和12周行X线片检查和生物力学检测。结果术后大体观察,A3、A6、B3、B6和C组间无显著差异,D组骨痂少且断端更为明显。各时间点组织学观察,A3、A6、B3、B6和C组植入材料周围胶原及骨痂均较D组明显,术后12周组织学评分,D组与其它各组比较P值<0.05。X线片示D组植入材料皮质骨无明显变化,骨痂较少;余各组12周植入材料与自体骨融合,髓腔开通,骨折线消失,塑形好。生物力学检测D组与其它各组比较P值<0.05。结论以4℃和-196℃保存方法能有效保存组织工程骨,对修复骨缺损有明显效果,这一方法适宜推广应用。     

聚磷酸钙纤维/磷酸钙骨水泥复合材料修复骨缺损的实验研究

目的：探讨聚磷酸钙纤维（calcium polyphosphate fiber，CPPF）和磷酸钙骨水泥（calcium phosphate cement．CPC）复合材料修复骨缺损的能力及作为人工骨修复替代材料的可行性。方法：选用新西兰大白兔双侧桡骨制作骨缺损模型，将CPPF／CPC复合材料植入左侧骨缺损处，右侧骨缺损以自体微小颗粒骨植入作为实验对照，另做不植入任何物质的骨缺损作空白对照。在2、4、8、12周时分别进行大体观察、X线摄片、组织学切片观察，8、12周时进行扫描电镜观察及骨密度测定，12周时进行力学测试。结果：CPPF／CPC人工骨组与微小颗粒骨组骨缺损均完全修复，空白对照组骨缺损未见修复，CPPF／CPC与微小颗粒骨两组间X线评分、骨密度及力学测试指标比较，差异均无统计学意义（P〉0．05）。结论：CPPF／CPC复合材料具有良好的骨传导能力、力学特性及生物相容性，有望成为骨组织工程中修复骨缺损的理想材料。     

PLGA-TCP-BMP-2人工骨结合带血供自体骨修复骨缺损

[目的]研究PLGA-TCP-BMP-2人工骨结合自体带血供自体尺骨移植修复大段骨缺损的效果.[方法]手术造成30 mm绵羊桡骨骨缺损,A组置入PLGA-TCP-BMP-2人工骨及带血运的长段尺骨,B组仅置入PLGA-TCPBMP-2人工骨,C组不置人任何材料.3组均以钢板固定骨缺损区.术后24周拍摄X线片并处死动物,进行组织学观察评价.[结果]X线检查示A组桡骨缺损处完全成骨修复,皮质骨与髓腔的轮廓清晰;B组亦能完全修复,但新生骨密度及髓腔轮廓清晰度均不如A组;C组无有效骨痂形成.组织学检查示A、B组骨痂外层形成为板层骨,C组缺损区可见大量纤维组织填充.[结论]PLGA-TCP-BMP-2人工骨结合自体带血供长段尺骨移植能够很好的修复绵羊桡骨30 mm的骨缺损.     

自体颗粒骨磷酸钙骨水泥复合细胞移植的实验研究

目的探索应用自体颗粒骨磷酸钙骨水泥复合细胞修复骨缺损的效果。方法分离、定向诱导和扩增骨髓间充质干细胞(MSCs),观察其在体外培养的情况。体外复合自体颗粒骨与磷酸钙骨水泥,然后复合MSCs,并以电镜观察复合物在体外培养的情况。在动物模型中,以不同的复合物植入大鼠直径5mm的颅骨缺损,并于术后摄X线片及进行组织学观察。结果颗粒骨、CPC和MSCs的复合材料可以修复骨缺损,效果优于其他实验组,相比较有显著性差异(P<0．05)。结论颗粒骨、CPC和MSCs的复合材料可以再生骨组织,可以用于修复骨缺损。     

Repairing peripheral nerve defects with tissue engineered artificial nerves in rats

Objective： To observe the effect of tissue engineered nerves in repairing peripheral nerve defects （ about 1. 5 cm in length） in rats to provide data for clinical application.
Methods： Glycerinated sciatic nerves （2 cm in length） from 10 Sprague Dawiey （SD） rats （aged 4 months） were used to prepare homologous dermal acellular matrix. Other 10 neonate SD rats （aged 5-7 days） were killed by neck dislocation. After removing the epineurium, the separated sciatic nerve tracts were cut into small pieces, then digested by 2.5 g/L trypsin and 625 U/nd collagenase and cultured in Dulbecco＇ s modified Eagle＇ s medium （DMEM） for 3 weeks. After proliferation, the Schwann cells （SCs） were identified and prepared for use. And other 40 female adult SD rats （ weighing 200 g and aged 3 months） with sciatic nerve defects of 1.5 cm in length were randomly divided into four groups： the defects of 10 rats bridged with proliferated SCs and homologous dermal acellular matrix （the tissue engineered nerve group, Group A）, 10 rats with no SCs but homologous dermal acellular matrix with internal scaffolds （Group B ）, 10 with autologous nerves （Group C ）, and the other 10 with nothing （the blank control group, Group D）. The general status of the rats was observed, the wet weight of triceps muscle of calf was monitored, and the histological observation of the regenerated nerves were made at 12 weeks after operation.
Results： The wounds of all 40 rats healed after operation and no death was found. No foot ulceration was found in Groups A, B and C, but 7 rats suffered from foot ulceration in Group D. The triceps muscles of calf were depauperated in the experimental sides in all the groups compared with the uninjured sides, which was much more obvious in Group D. The wet weight of triceps muscle of calf and nerve electrophysiologic monitoring showed no statistical difference between Group A and Group C, but statistical difference was found between Groups A and B and Groups B and     

微小颗粒骨移植骨细胞活性的实验研究

目的 观察微小颗粒骨在移植修复骨缺损过程中的骨细胞存活情况和生物活性. 方法 建立大鼠桡骨骨缺损模型,近交系DA大鼠88只,其中雄性大鼠28只,作为供体;雌性大鼠60只,作为受体.将受体随机分为块状骨组(n=56)、微小颗粒骨组(n=56)和空白对照组(n=4),取雄性大鼠髂骨为供体骨,分别制成直径为2mm的骨块和直径为300～500 μm的微小颗粒骨,植入骨缺损,于术后1 d、4 d、1周、2周、4周、6周、10周取材,采用原位杂交的方法观察受体内Y染色体性别决定基因(Sry)的表达情况,应用免疫组化法观察各组骨形态发生蛋白-2(BMP～2)、转化生长因子-β1(TGF-β1)、碱性磷酸酶(ALP)和I型胶原的表达情况. 结果 块状骨组在移植早期Srv的表达逐渐减少,至1周消失,4周后再次出现,并且随时间延长表达逐渐增多;微小颗粒骨组各时间段均有Sry的表达,在同一时间点,微小颗粒骨组Sry的阳性细胞数多于块状骨组(P<0.05),两种骨移植物中参与修复骨缺损的细胞类型不同.微小颗粒骨内和周围组织中BMP-2、TGF-β1、ALP和Ⅰ型胶原的阳性细胞数在术后2周内多于块状骨组(P<0.05). 结论 微小颗粒骨与块状骨修复骨缺损时均有供体骨细胞参与,但微小颗粒骨内有更多的骨细胞存活.微小颗粒骨内存活的骨细胞具有生物学活性,合成并分泌骨生长因子和骨基质蛋白,可以加速骨缺损的修复.     

海绵状、泥灰状脱钙骨基质修复骨缺损

目的探讨海绵状脱钙骨基质(DBM)和泥灰状DBM修复骨缺损的能力。方法将兔四肢长骨骨干脱脂、脱钙后制成长度为500～1000 μm的纤维状及直径为200～400μm的颗粒状DBM,并与2%明胶混合分别制成海绵状DBM和泥灰状DBM。在9只兔双侧桡骨中段做一长10mm的骨膜骨缺损,分别植入海绵状DBM和泥灰状DBM及空白对照,每组各6个缺损,术后观察6周,于4、6周时拍摄X线片,并对实验动物的大体标本、骨密度、生物力学、新生骨矿化率及病理组织学改变进行观察。结果术后4、6周X线片显示两实验组骨缺损均修复,骨髓腔完整;空白对照组无一例修复骨缺损。骨密度测量显示海绵状DBM组新生骨骨密度与正常桡骨间差异无显著性(P >0.05),但泥灰状DBM组的新生骨骨密度与正常桡骨间差异有显著性(P< 0.05)。术后6周生物力学测定显示海绵状DBM组新生骨极限压缩强度值与正常桡骨差异无显著性(P >0.05),泥灰状DBM组低于正常桡骨且差异有显著性(P< 0.05)。两实验组新生骨矿化率差异无显著性(P >0.05)。组织学观察显示两实验组中DBM绝大部分被吸收,形成板状骨骨小梁及完整的骨髓腔,塑形完整, 新生骨内可见骨单位及局部尚未完全骨化的新生骨。结论海绵状DBM和泥灰状DBM均具有诱导成骨活性和骨传导能力,使用方便,新生骨塑形完整,生物力学强度高,矿化     

A clinical study of alveolar bone tissue engineering with cultured autogenous periosteal cells: coordinated activation of bone formation and resorption

In ongoing clinical research into the use of cultured autogenous periosteal cells (CAPCs) in alveolar bone regeneration, CAPCs were grafted into 33 sites (15 for alveolar ridge augmentation and 18 for maxillary sinus lift) in 25 cases. CAPCs were cultured for 6weeks, mixed with particulate autogenous bone and platelet-rich plasma, and then grafted into the sites. Clinical outcomes were determined from high-resolution three-dimensional computed tomography (3D-CT) images and histological findings. No serious adverse events were attributable to the use of grafted CAPCs. Bone regeneration was satisfactory even in cases of advanced atrophy of the alveolar process. Bone biopsy after bone grafting with CAPCs revealed prominent recruitment of osteoblasts and osteoclasts accompanied by angiogenesis around the regenerated bone. 3D-CT imaging suggested that remodeling of the grafted autogenous cortical bone particles was faster in bone grafting with CAPCs than in conventional bone grafting. The use of CAPCs offers cell-based bone regeneration therapy, affording complex bone regeneration across a wide area, and thus expanding the indications for dental implants. Also, it enables the content of particulate autogenous bone in the graft material to be reduced to as low as 40%, making the procedure less invasive, or enabling larger amounts of graft materials to be prepared. It may also be possible to dispense with the use of autogenous bone altogether in the future. The results suggest that CAPC grafting induces bone remodeling, thereby enhancing osseointegration and consequently reducing postoperative waiting time after dental implant placement.     

Isoflavones prevent bone loss following ovariectomy in young adult rats

Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day) diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy.     

自体髂骨复合PRF修复牙槽嵴裂的实验研究

目的:将富血小板纤维蛋白(Pl at el et-ri ch fi bri n,PRF)应用于牙槽嵴裂植骨手术,验证其是否能够减少植骨术后的骨吸收。方法:8～12月龄犬8只,以外科手术的方法制备双侧牙槽嵴裂模型,随机于两侧同期植入自体髂骨(对照组)及自体髂骨混合PRF(实验组)。于术后当日、2个月、4个月时拍摄上颌骨CT,利用三维重建软件测量植骨区体积,计算骨吸收率。结果:术后2个月、4个月时实验组的骨吸收率明显小于对照组,行配对样本的t检验,P<0.01。结论:将PRF加入自体髂骨进行骨移植修复犬的牙槽嵴裂,在术后4个月的时间范围内,可以减少术后的骨吸收。     

骨髓基质干细胞联合血管束植入构筑血管化组织工程骨修复兔大段骨缺损

目的 研究兔骨髓基质干细胞(BMSCs)联合动静脉血管束植入异种脱蛋白松质骨(XDCB)构筑血管化组织工程骨修复兔桡骨中远段完全骨膜骨缺损的能力. 方法 从兔髂嵴捕骨髓培养制备兔BMSCs,将第5代BMSCs种植于多孔XDCB,并进行成骨诱导2周制备组织工程骨,手术中分离兔桡动、静脉血管束.动物模型为制备24只兔舣侧桡骨中远段完全骨膜骨缺损1.5 cm共48侧,分4组修复(n=12),A组为空白未治疗组,B组为单纯材料+血管束植入组(XDCB+VB),C组为组织工程骨组(XDCB+BMSCs),D组为组织工程骨+血管束植入组(XDCB+BMSCs+VB),符组交叉配对.分别于术后4、8、12周行X线片、大体解剖、组织切片、生物力学等检查,观察各组骨缺损修复效能及移植物血管化情况.结果 D组骨缺损修复效能(术后12周新骨面积比2.02%±0.16%)及血管化情况(术后12周血管面积比6.89%±0.32%)优于C组(1.50%±0.28%和3.17%±0.19%),而C组又优于B组(1.59%±0.19%和6.52%±0.23%),A组骨缺损未修复,各组结果差异有统计学意义(P<0.05).结论 BMSCs联合动静脉血管束植入构筑的血管化组织工程骨能促进成骨过程和新生骨的血管化,显著提高组织工程骨修复大段骨缺损的能力.     

Morselized bone grafting of defects in revision total knee arthroplasty.

In a prospective, multicenter study evaluating one revision knee system, 33 of 409 patients underwent morselized bone grafting for tibial and femoral defects. Fifty-four percent of defects were bicondylar and the defect volumes averaged 36 cc3. There was no difference in preoperative or postoperative knee scores between patients undergoing morselized grafting and the entire group. Radiographic evaluation showed remodeling of the grafted areas consistent with viable incorporation of the graft. The incidence of radiolucent lines, at 2 years followup, was not different between the patients who received grafting and the patients who did not receive grafting. There have been no clinical failures or reoperations in the patients who received morselized bone grafting. Morselized bone grafting seems to offer a viable alternative in the reconstruction of osseous defects in patients undergoing revision total knee arthroplasty.     

Rinsing of allograft bone does not improve implant fixation

Background and purpose Impacted morselized allograft bone is a well-established method for reconstructing bone defects at revision surgery. However, the incorporation of bone graft is not always complete, and a substantial volume of fibrous tissue has been found around grafted implants. We hypothesized that rinsing the bone graft may improve graft incorporation by removing the majority of immunogenic factors present in blood, marrow, and fat.

Methods We implanted a cylindrical (10- × 6-mm) porous-coated Ti implant into each proximal tibia of 12 dogs. The implants were surrounded by a 2.5-mm gap into which morselized fresh frozen allograft bone was impacted. The bone graft was either (1) untreated or (2) rinsed in 37°C saline for 3 × 1 min. After 4 weeks, the animals were killed and implant fixation was evaluated by mechanical push-out and histomorphometry.

Results The groups (rinsed vs. control) were similar regarding mechanical implant fixation (mean (SD)): shear strength (MPa) 2.7 (1.0) vs. 2.9 (1.2), stiffness (MPa/mm) 15 (6.7) vs. 15 (5.6), and energy absorption (kJ/m²) 0.5 (0.2) vs. 0.6 (0.4), The same was evident for the new bone formation on the implant surface and around the implant: ongrowth (%) 6 vs. 7 and ingrowth (%) 9 vs. 9. Although not statistically significant, a 61% reduction in fibrous tissue ongrowth and 50% reduction in ingrowth were found in the rinsed group.

Interpretation Within the limits of this experimental model, we did not detect any benefits of rinsing morselized allograft bone prior to impaction grafting.