Garbuz Donald S, Hu Youxin, Kim Winston Y, Duan Ke, Masri Bassam A, Oxland Thomas R, Burt Helen, Wang Rizhi, Duncan Clive P
Division of Adult Lower Limb Reconstruction and Oncology, Department of Orthopaedics, University of British Columbia, Room 3114, 910 West 10th Avenue, Vancouver, BC V5Z 4E3, Canada.
J Bone Joint Surg Am. 2008 May;90(5):1090-100. doi: 10.2106/JBJS.G.00415.
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.
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 undecalcified samples.
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.
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.
已证明多孔钽在实现骨长入方面是有效的。然而，在某些情况下，骨质量或骨量可能不足以实现充分的骨长入。我们推测，当植入物与骨之间存在间隙时，从多孔钽局部递送阿仑膦酸盐将增强钽实现骨长入的能力。我们在一个植入物与骨之间存在间隙的动物模型中评估了阿仑膦酸盐涂层多孔钽对新骨形成的影响。
将圆柱形多孔钽植入物植入18只兔子每只股骨的远端（共36个植入物），并原位留置4周。插入三种类型的多孔钽植入物：无涂层的（对照组）、有微孔磷酸钙涂层的以及涂有微孔磷酸钙和阿仑膦酸盐的。使用皮下荧光标记来追踪新骨形成。通过背散射电子显微镜和未脱钙样品的荧光显微镜分析骨形成情况。
与未涂层多孔钽植入物治疗的对照组相比，涂有磷酸钙和阿仑膦酸盐的多孔钽植入物治疗组的间隙填充平均体积、骨长入和总骨形成的相对增加分别为143%（p < 0.001）、259%（p < 0.001）和193%（p < 0.001）。与未涂层植入物治疗组相比，涂有磷酸钙和阿仑膦酸盐涂层的治疗组中与新骨接触的植入物长度百分比平均增加了804%。
该研究表明，涂有磷酸钙和阿仑膦酸盐的多孔钽植入物能显著增强骨 - 植入物间隙的填充和骨长入。
