生物活性颈椎椎间融合器的三维运动稳定性实验

背景：前期实验已证实，以自行合成的羟基磷灰石/左旋聚乳酸复合材料研制的生物活性颈椎椎间融合器有良好的生物相容性。目的：进一步比较该生物活性颈椎椎间融合器和髂骨块的三维运动稳定性，以评价生物活性颈椎椎间融合器置入椎间后重建颈椎稳定性的效果。设计、时间及地点：体外生物力学实验，于2003-08/11在南方医科大学全军及广东省重点生物力学实验室完成。材料：生物活性颈椎椎间融合器是利用羟基磷灰石/左旋聚乳酸复合而成由南方医科大学珠江医院提供（专利号为：03236843.7）。6具新鲜人尸体颈椎标本C1~T1节段，均分为3组：正常组、髂骨组及生物活性颈椎椎间融合器组。方法：在6具新鲜人尸体颈椎标本的C5与C6椎间盘处，行颈前路环锯减压后，髂骨组及生物活性颈椎椎间融合器组分别置入自体髂骨和生物活性颈椎椎间融合器，正常组为完整结构标本，不予进行任何处理。主要观察指标：利用测量系统测量3组颈椎节段间前屈、后伸、左/右侧弯和左/右轴向旋转等三维运动范围。结果：在椎间盘切除椎间置入生物活性颈椎椎间融合器后，在前屈、左右侧弯和左右轴向旋转的运动范围均较椎间置入髂骨组减少，较髂骨组稳定，差异有统计学意义（P < 0.01）。在后伸状态下椎间置入生物活性颈椎椎间融合器和髂骨置入物与正常组比较运动范围增大，但差异无统计学意义。结论：生物活性颈椎椎间融合器置入椎间后颈椎稳定性良好，置入椎间后较椎间置入髂骨稳定。

Three-dimensional motion stability test of bioactive cervical fusion cage

BACKGROUND: Previous studies have demonstrated the good biocompatibility of bioactive cervical fusion cage (BCFC) comprising hydroxyapatite and poly-L-lactic acid. OBJECTIVE: To compare three-dimensional motional stability of iliac crest bone and BCFC, so as to investigate the immediate effects and initial stability of cervical vertebrae interbody fusion. DESIGN, TIME AND SETTING: In vitro biomechanical experiment was performed at the Laboratory of Institute of Biomechanics, Southern Medical University from August to November 2003.MATERIALS: BCFC, made of hydroxyapatite and poly L-lactic acid, was provided by Zhujiang Hospital, Southern Medical University (patent number: 03236843.7). Six C1-T1 segments from fresh human cervical spine specimens were excised and randomly divided into intactl, iliac crest bone, and BCFC groups.METHODS: BCFC and iliac crest bone were used for anterior interbody implants after anterior discectomy across C5-C6 in six fresh human cervical spine specimens. Normal group was not given any treatment. MAIN OUTCOME MEASURES: The range of motion was measured by a three dimensional spinal stability test.RESULTS: After discectomy, BCFC exhibited an decrease in angular motion than iliac crest bone but a significant increase in stability in flexion, left/right lateral bending and left/right axial rotation (P < 0.01). In backward extension, both BCFC and iliac crest bone showed an increase in range of motion than the intact specimen, but the difference was not significant. CONCLUSION: BCFC could remain or increase the immediate effects and initial stability of cervical vertebrae.