多孔钛合金不同孔径大小对新骨长入的影响

目的:评价不同孔径多孔钛合金植入物在骨缺损区对新骨长入的影响。方法:采用电子束熔融(EBM)技术制备三种不同孔径(孔径分别为1.0 mm,2.0 mm,3.0 mm)的多孔钛合金材料,其孔隙率依次为73%,79%,86%。将18只家犬随机分为1.0 mm孔径材料组,2.0 mm孔径材料组,3.0 mm孔径材料组,每组6只。制备家犬双侧股骨外侧髁缺损模型,然后植入各孔径组材料,于术后4周,8周,12周分别行大体标本观察,X线片观察,组织形态学观察三组不同孔径材料与周围骨的整合情况及孔隙中的新骨长入情况。结果:通过大体标本观察和X线片观察显示,12周后三组材料均与周围紧密骨连接。其中1.0 mm孔径组材料中心明显成骨,2.0 mm孔径组和3.0 mm孔径组中心仍为较多白色组织填充。组织学观察显示,12周时2.0 mm孔径组和3.0 mm孔径组材料周围有骨质包绕,但中心空洞,基本无骨质形成。1.0 mm孔径组材料周围骨质包绕紧密,孔中新生骨形成较多,且有大量纤维母细胞和软骨细胞形成。各时间点1.0 mm孔径组新生骨面积百分比明显高于2.0 mm孔径组和3.0 mm孔径组,P<0.01,差异具有统计学意义。2.0 mm孔径组和3.0 mm孔径组相比,P>0.05,无显著差异。结论:孔径大小影响多孔钛合金材料的骨长入,适当孔径的设计将更有利于材料的传导成骨。

Effect of Pore Sizes of Porous Titanium Alloys as Bone Material on Bone Formation

Objective:To investigate the effect of regeneration as porous titanium alloys with three different pore sizes.Methods: Porous titanium alloys with three different pore sizes(1.0 mm,2.0 mm,3.0 mm) and three different porosities(73%,79%,86%),were made by Electron Beam Machining(EBM).They were implanted the defects of condylus lateralis femoris of 18 dogs.The 18 dogs were randomly divided into three experimental groups.The specimens were harvested after 4,8,12 weeks,then were examined by gross observation,X ray and histological.Results: The gross observation and X-ray observations revealed,three groups of materials were closely related with the surrounding bone after 12 weeks.The implant with 1.0 mm pore size was obvious bone formation in the materials center,the center of the implant with 2.0 mm pore size and the implant with 3.0 mm pore size was still more white tissue filling.There were a large number of bone formation around the the implant with 2.0 mm pore size and the implant with 3.0 mm pore size of meterials after 12 weeks,but there was no bone formation in the center.The implant with 1.0 mm pore size was wrapped tightly by the bone,new bone formation more in holes of the center,and a large number of fibroblasts and chondrocytes were formed.Area percentage of new bone formation in the implant with 1.0 mm pore size was significantly higher than the implant with 2.0 mm pore size and the implant with 3.0 mm pore size at each time point,P<0.01,the difference was statistically significant.The implant with 2.0 mm pore size compared with the implant with 3.0 mm pore size,P>0.05,there was no significant difference.Conclusion: Pore size of porous titanium alloy materials have effection for bone ingrowth,appropriate aperture design will be more conducive to bone conduction.