Enhanced gap filling and osteoconduction associated with alendronate-calcium phosphate-coated porous tantalum
Enhanced gap filling and osteoconduction associated with alendronate-calcium phosphate-coated porous tantalum
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DOI：
10.2106/jbjs.g.00415
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发表时间：
2008-05-01
影响因子：
5.3
通讯作者：
Duncan, Clive P.
中科院分区：
文献类型：
--
作者：
Garbuz, Donald S.;Hu, Youxin;Duncan, Clive P.
背景：多孔钽已被证明对实现骨长入是有效的。然而，在某些情况下，骨的质量或数量可能不足以允许足够的骨长入。我们假设，当种植体和骨之间存在间隙时，从多孔钽中局部递送阿仑膦酸盐可以增强钽实现骨长入的能力。我们评估了阿仑膦酸盐涂层多孔钽在植入物和骨之间存在间隙的动物模型中对新骨形成的影响。方法：18只兔（共36颗）在股骨远端植入圆柱形多孔钽种植体，放置四周。植入三种多孔钽种植体：无涂层组（对照组）、微孔磷酸钙涂层组、微孔磷酸钙和阿仑膦酸盐涂层组。皮下荧光标记用于跟踪新骨形成。用背散射电镜和荧光显微镜对未钙化的标本进行骨形成分析。结果：磷酸钙和阿仑膦酸盐包被多孔钽种植体组与未包被多孔钽种植体对照组相比，空隙填充、骨长入和总骨形成的平均相对体积分别增加143% （p < 0.001）、259% （p < 0.001）和193% （p < 0.001）。使用磷酸钙和阿仑膦酸盐涂层的组与未使用涂层的组相比，种植体与新骨接触的长度百分比平均增加了804%。结论：该研究表明，磷酸钙和阿仑膦酸盐涂层的多孔钽种植体显著增强了骨-种植体间隙的填充和骨长入。临床意义：添加阿仑膦酸盐表面涂层可以增强钽种植体的生物固定，促进骨缺损的愈合，从而解决骨丢失情况下翻修关节置换术的临床问题。
Background: Porous tantalum has been shown to be effective in achieving bone ingrowth. However, in some circumstances, bone quality or quantity may be insufficient to allow adequate bone ingrowth. We hypothesized that local delivery of alendronate from porous tantalum would enhance the ability of the tantalum to achieve bone ingrowth when there is a gap between the implant and bone. We evaluated the effect of alendronate-coated porous tantalum on new bone formation in an animal model incorporating a gap between the implant and bone.Methods: A cylindrical porous tantalum implant was implanted in the distal part of each femur in eighteen rabbits (a total of thirty-six implants) and left in situ for four weeks. Three types of porous tantalum implants were inserted: those with no coating (the control group), those with microporous calcium phosphate coating, and those coated with microporous calcium phosphate and alendronate. Subcutaneous fluorescent labeling was used to track new bone formation. Bone formation was analyzed with backscattered electron microscopy and fluorescent microscopy of unclecalcified samples.Results: The relative increases in the mean volume of gap filling, bone ingrowth, and total bone formation in the group treated with the porous tantalum implants coated with calcium phosphate and alendronate were 143% (p < 0.001), 259% (p < 0.001), and 193% (p < 0.001), respectively, compared with the values in the control group treated with the uncoated porous tantalum implants. The percentage of the length of the implant that was in contact with new bone in the group treated with the calcium phosphate and alendronate coating was increased by an average of 804% compared with the percentage in the group treated with the uncoated implants.Conclusions: The study demonstrated significantly enhanced filling of the bone-implant gap and bone ingrowth in association with the porous tantalum implants coated with calcium phosphate and alendronate.Clinical Relevance: The addition of an alendronate-delivery surface coating would enhance biological fixation of a tantalum implant and promote the healing of bone defects and thus address the clinical problem of revision joint replacement in the face of bone loss.