IN-VIVO EVALUATION OF ANTERIOR CERVICAL FUSIONS WITH HYDROXYLAPATITE GRAFT MATERIAL
IN-VIVO EVALUATION OF ANTERIOR CERVICAL FUSIONS WITH HYDROXYLAPATITE GRAFT MATERIAL
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DOI：
10.1097/00007632-199408150-00011
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发表时间：
1994-08-15
期刊：
影响因子：
3
通讯作者：
WHITECLOUD, TS
中科院分区：
文献类型：
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作者：
COOK, SD;DALTON, JE;WHITECLOUD, TS
研究设计.在犬模型中研究了固体羟基磷灰石（HA）块用于获得颈椎椎间融合的有效性。21只成年群体饲养的猎犬在C3-C4和C5-C6椎间盘间隙接受羟基磷灰石植入物和自体骨移植物。分别于术后6、12、26周处死7只犬。本研究确定了使用羟基磷灰石（HA）块实现颈椎椎体间融合的比率、机械强度和组织学特征，并将结果与自体髂嵴骨移植物获得的结果进行了比较。在颈椎前路椎体间融合术中，自体皮质松质骨移植物的使用已获得很高的成功率。磷酸钙陶瓷可以提供一种替代自体和异体组织。这些材料具有生物相容性，并且由于它们与骨矿物的化学相似性而能够与骨直接紧密结合。影像学评价包括X线平片、计算机断层扫描（CT）和磁共振成像（MRI）研究，用于确定融合质量。还对样本进行了机械测试，以确定弯曲和扭转刚度以及失效极限载荷。组织学评价包括移植材料的完整性和结合以及界面特征。CT图像与X线平片具有良好的相关性，并显示随着时间的推移，移植物材料逐渐融合。磁共振成像在评价融合质量方面价值不大;自体植骨部位显示椎间盘高度随时间推移逐渐降低。使用HA块观察到最小椎间盘高度损失。在任何时间段，HA块和自体骨移植物的扭转刚度均无统计学差异。在弯曲试验中，6周时HA阻滞部位明显更硬（P < 0.005）。HA和自体骨移植物的极限失效载荷没有统计学差异。在组织学上，HA块显示出直接骨附着区域，随着时间的推移，骨附着和植入物结合增加。在术后6周和12周，自体移植部位显示移植物吸收和一些新骨形成。到26周时，新骨与椎体终板连续。结果表明，HA块可为颈椎前路椎间融合术提供自体移植物材料的替代品。少数患者可能会发生块滑动和/或断裂，但主要与插入技术相关，似乎不会显著改变最终结果。
Study Design. The efficacy of solid hydroxylapatite (HA) blocks for obtaining cervical interbody fusion was studied in a canine model. Each of 21 adult colony-reared hounds received a hydroxylapatite implant and an autogenous bone graft in the C3-C4 and C5-C6 disc interspaces. Seven dogs each were killed at 6, 12, and 26 weeks postoperation.Objective. This study determined the rate, mechanical strength, and histologic characteristics of cervical interbody fusions achieved using a hydroxylapatite (HA) block and compared the results to those obtained with autogenous iliac crest bone graft.Summary of Background Data. The use of corticocancellous autograft has been successful in a high percentage of anterior cervical interbody fusions. Calcium phosphate ceramics may provide an alternative to autogenous and allogenous tissue. These materials are biocompatible and capable of direct intimate bonding with bone because of their chemical similarity to bone mineral.Methods. Radiographic evaluation including plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) studies were used to determine fusion quality. Specimens were also subjected to mechanical testing to determine bending and torsional stiffness as well as ultimate load to failure. Histologic evaluation included integrity and incorporation of the graft materials and interface characterization.Results. The CT images were well correlated with plain radiographs and demonstrated progressive incorporation of the graft materials with time. Magnetic resonance images were of little value in evaluating quality of fusion; the autograft sites demonstrated progressive disc height loss with time. Minimal disc height loss was observed with HA blocks. There was no statistical difference in torsional stiffness for the HA blocks and autogenoUs bone grafts at any time period. In bending, the HA block sites were significantly stiffer at 6 weeks (P < 0.005). There was no statistical difference in the ultimate failure load for the HA and autogenous bone grafts. Histologically, the HA blocks demonstrated areas of direct bone apposition with increased bone appositions and implant incorporation with time. At 6 and 12 weeks postoperation, the autograft sites demonstrated areas of graft resorption and some new bone formations. By 26 weeks, new bone was continuous with the vertebral endplates.Conclusions. The results indicate that HA blocks may provide an alternative to autogenous graft materials for anterior cervical interbody fusion. Block slippage and/or fracture may occur in a small number of patients but is primarily related to insertion technique and does not appear to significantly alter the final result.