Xie Youzhuan, Chopin Daniel, Hardouin Pierre, Lu Jianxi
Department of Orthopaedics, Ninth People's Hospital, Shanghai Second Medical University, 200011, Shanghai, China.
Eur Spine J. 2006 Aug;15(8):1196-203. doi: 10.1007/s00586-005-0052-1. Epub 2006 Jan 21.
Few histological studies on bone substitutes in human cervical spine are available and the biological processes of bone substitutes are not well documented. The authors studied four failure cases of cervical interbody fusion: two cases with hydroxyapatite (HA), one case with beta-tricalcium phosphate ceramic (beta-TCP) and one case with xenograft (bovine bone). Clinical data showed that all the patients experienced neck pain with or without numbness of upper extremity due to fusion failure. Successful fusions were achieved after the salvage surgeries in which autograft were used. Radiographs showed that radiolucent lines were present in all cases. Two HA substitutes fractured without complications. One of them sank into the vertebral body. Some small beta-TCP fragments were found under the microscope. Histological study demonstrated only a few newly formed bones at the interface of the substitutes. The fragments of HA were encapsulated by fibrous tissue. The degradation process and bone regeneration were more active in beta-TCP than in HA. The intertrabecular spaces of bovine bone were filled with fibrous tissue. The results suggest that a porous calcium phosphate ceramic with special design might assure bone ingrowth and meet the mechanical requirements in cervical interbody fusion. The complications of these materials in the cervical spine should be highlighted.
关于人类颈椎骨替代物的组织学研究很少，骨替代物的生物学过程也没有得到充分记录。作者研究了4例颈椎椎间融合失败的病例：2例使用羟基磷灰石（HA），1例使用β-磷酸三钙陶瓷（β-TCP），1例使用异种移植物（牛骨）。临床数据显示，所有患者均因融合失败而出现颈部疼痛，伴有或不伴有上肢麻木。在采用自体骨进行挽救手术后实现了成功融合。X线片显示所有病例均存在透亮线。2个HA替代物发生骨折，无并发症。其中1个沉入椎体。在显微镜下发现了一些小的β-TCP碎片。组织学研究表明，在替代物界面处仅形成了少量新骨。HA碎片被纤维组织包裹。β-TCP的降解过程和骨再生比HA更活跃。牛骨的小梁间隙充满了纤维组织。结果表明，具有特殊设计的多孔磷酸钙陶瓷可能确保骨长入并满足颈椎椎间融合的力学要求。应强调这些材料在颈椎中的并发症。
