Mechanical evaluation of a canine intervertebral disc spacer: In situ and In vivo studies
Mechanical evaluation of a canine intervertebral disc spacer: In situ and In vivo studies
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犬椎间盘垫片的机械评估：原位和体内研究
DOI：
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发表时间：
1994
影响因子：
2.8
通讯作者：
N. Langrana
中科院分区：
文献类型：
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作者：
Monica Vuono‐Hawkins;M. Zimmerman;Casey K. Lee;F. Carter;J. Parsons;N. Langrana
将具有羟基磷灰石嵌入面的弹性间盘间隔物植入犬模型。我们研究了(A)运动节段在0、3、6和12个月时的力学行为，以及(B)间隔器和椎骨之间的界面对种植体稳定性和骨长入的影响。设计了一种聚合物间隔物，其压缩和扭转特性类似于犬腰椎间盘的压缩和扭转特性。在犬身体活动节段植入间隔器，可以在0。一项活体研究允许对动物进行持续的神经学监测，评估3、6和12个月时的机械行为、稳定性和内长。用原位间隔器对身体运动节段进行的力学测试导致压缩和扭转刚度降低，平均分别为25%和42%。这一下降是由于手术对椎体终板环的侮辱和相邻椎体终板的剥离所致。在活体研究中，所有12只动物都很好地耐受了手术，没有一只有永久性的神经损伤。测量的参数表明，间隔器-运动节段复合材料的行为似乎在3-6个月内恢复正常。然而，尽管在植入物表面使用了多孔羟基磷灰石，但没有明显的骨生长。相反，在间隔器-椎骨交界处形成了一层致密的纤维结缔组织。12个间隔物中的5个早期移位导致偏心负荷模式与一致的反应性骨赘形成。
An elastomeric intervertebral disc spacer with hydroxyapatite ingrowth surfaces was implanted in a canine model. We studied (a) the mechanical behavior of motion segments at time 0 and at 3, 6, and 12 months and (b) the effect of the interface between the spacer and vertebral bone on implant stability and bone ingrowth. A polymeric spacer was designed with compressive and torsional properties similar to those of the isolated canine lumbar disc. Implantation of the spacer in canine cadaver motion segments permitted in situ biomechanical evaluation at time 0. An in vivo study permitted continuous neurological monitoring of animals, with evaluation of mechanical behavior, stability, and ingrowth at 3, 6, and 12 months. Mechanical testing of cadaver motion segments with the spacer in situ resulted in decreased compressive and torsional stiffnesses, averaging 25 and 42%, respectively. This decrease was due to a combination of the surgical insult to the annulus and decortication of adjacent vertebral endplates. In the in vivo study, all 12 animals tolerated the surgery well and none had permanent neurological impairment. The measured parameters indicated that behavior of the spacer‐motion segment composite appeared to return to normal within 3‐6 months. However, despite use of a porous hydroxyapatite on the implant surface, there was no significant bone ingrowth. Instead, a layer of dense fibrous connective tissue was formed at the spacer‐vertebral bone interface. Early migration of five of the 12 spacers resulted in eccentric loading patterns with consistent reactive osteophyte formation.