New type of prosthesis combined with rhBMP-2 delivery system

全髋关节置换术被广泛接受用于重建受损的髋关节，尽管存在潜在的机械松动风险和不可避免的翻修手术。在这类翻修手术中，我们经常会遇到股骨近端或髋臼不同程度的假体周围骨缺损，即使使用自体或异体骨移植和各种生物材料，也往往难以获得稳定的假体置入。为了解决这个问题，我们设计了一种新的修复骨缺损的方法，使用DNA重组产生的人型生长因子骨形态发生蛋白-2(rhBMP-2)和新型合成可生物降解聚合物(PLA-DX-PEG)作为载体材料来传递rhBMP-2。在这份报告中，我们介绍了重组人骨形态发生蛋白-2保留假体重建犬模型骨缺损的效果。在这个模型中，手术切除股骨头和股骨近端的内侧半部分以制作骨…。还有更多的缺陷需要修复。植入重组骨形态发生蛋白-2(100μ、500μg或1000μg)/聚乳酸-DX-聚乙二醇(100 Mg)复合材料的局部多孔结构表面假体。在对照动物中，将不含重组人骨形态发生蛋白-2的聚乳酸-DX-聚乙二醇聚合物填充到多孔表面。术后2周、4周、8周、12周分别行X线平片检查近端骨缺损处的新骨形成情况。100500μg和1000μg重组人骨形态发生蛋白-2组(n=4)在4周后出现明显的不透射线阴影，且不透射线区的大小与剂量有关。术后8周，不透X线阴影更明显。在对照动物中，在实验期间，骨缺损处没有观察到不透射线的阴影。术后12周处死动物，取股骨近端。在大体组织学和放射学方面，500m和1000mμ-g重组人骨形态发生蛋白-2组的原始骨缺损完全修复，假体良好固定在股骨近端。100μg组用薄层新生骨部分修复。在对照组中，缺损处未修复，由纤维组织覆盖。光镜下观察，12周后新生骨被改建为板层骨。综上所述，这种假体结合重组人骨形态发生蛋白-2输送系统可能为我们提供一种新的方式来修复翻修关节成形术中遇到的骨缺损或丢失的骨量，而不需要植骨。较少

Total hip arthroplasty is widely accepted for reconstruction of damaged hip joints in spite of potential risk for mechanical loosening and inevitable revision surgery. In such revision surgeries, we often encounter peri-prosthetic bone defects of various grades either in proximal femur or in acetabulum, which often make difficult to obtain stable setting of a new hip prosthesis even if with use of auto- or allogenous bone grafting and various biomaterials. In order to address this problem, we devised new method to repair the bone defect with use of a growth factor bone morphogenetic protein-2 of human type, produced by DNA recombination ( rhBMP-2) in combination with a new synthetic biodegradable Polymer( PLA-DX-PEG ) as a carrier material for the rhBMP-2 delivery. In this report we present the efficacy of the rhBMP-2 retaining prosthesis to reconstruct bone defect in a canine model. In this model, femoral head and medial halfofthe proximal femur was surgically resected to make the bon … More e defect to be repaired. And the prosthesis with partially porous structured Surface which was impregnated with rhBMP-2 ( 100 μ, 500 μ g or 1000 μ g )/PLA-DX-PEG( 100mg ) composite. In control animals, PLA-DX-PEG polymer without rhBMP-2 was packed into the porous surface. New bone formation at the proximal bone defects was examined by routine radiography at 2, 4, 8 and 12 weeks after surgery. In 100, 500μ g and 1,000 μ g rhBMP-2 groups ( n=4 respectively ) definite radiopaque shadows appeared along the bone defects in 4 week and the sizes of the radiopaque area were depended on the rhBMP-2 doses. The radiopaque shadows became more obvious at 8 weeks alter surgery. In control animals, no radiopaque shadow was noted at the bone defect over the experimental period of time. At 12 weeks after surgery, the animals were sacrificed and proximal femurs were harvested. On macroscopic histology and radiology, original bone defects in 500 and 1,000m μ g rhBMP-2 groups were completely repaired and thef prostheses were well fixed within the proximal femurs. In 100 μ g group, the defects were partially repaired with thin new bone. In controls, the defects were left un-repaired and covered by fibrous tissue. On light microscopic examination, the newly formed bone was remodeled to lamellar bone in 12 weeks. In summary, this type of prosthesis combined with rhBMP-2 delivery system might provide us a new modality to restore bone defect or lost bone mass encountered in revision arthroplasty without bone grafting. Less