新型弧形带终板环颈椎钛网生物力学测试

Biomechanical Test on Novel Arc Cervical Titanium Mesh with Endplate Ring

目的建立山羊颈椎不稳定模型,测试新型弧形带终板环颈椎钛网的生物力学稳定性。方法测量成年山羊颈椎的解剖学数据,选择适合山羊颈椎的新型弧形带终板环颈椎钛网。将保留关节囊、韧带及椎间盘的24只山羊颈椎骨性标本随机分成4组。A组(正常组,n=6)无特殊处理,B组切除C4部分椎体及上下椎间盘(模型组,n=6);在B组基础上,C组安装新型弧形颈椎钛网并予钢板螺钉辅助固定(实验组,n=6),D组安装传统直型钛网并予钢板螺钉辅助固定(对照组,n=6)。测量4组标本在2.0 N·m载荷下前屈、左右侧弯、左右旋转、后伸时活动范围(range of motion,ROM),测试其三维运动稳定性。测量C、D两组在200 N压缩力下的位移,计算其刚度,测试其术后整体标本的抗沉降能力。结果A组各方向ROM均小于B组,A组各方向ROM均大于C组,C组前屈ROM小于D组(P<0.05);C组刚度较D组高(P<0.05);C组压缩位移较D组少(P<0.05)。结论新型弧形钛网较直型钛网更加符合颈椎生理曲度,在颈椎最频繁的前屈活动上稳定性较传统钛网好,且短期应力下压缩位移较直型钛网少,术后抗沉降较直型钛网好,值得进一步实验及临床推广。

Objective To establish the instability model of goat cervical vertebrae,and test biomechanical stability of the novel arc cervical titanium mesh with endplate ring.Methods The anatomical data from cervical vertebrae of adult goats were measured,so as to select a new type of arch cervical titanium mesh with endplate ring which was suitable for goat cervical vertebrae.A total of 24 goats with preserved articular capsule,ligaments and intervertebral disc were randomly divided into 4 groups.Group A(n=6,normal group)didn’t receive any special treatment,while Group B(n=6,model group)received partial resection of C4 vertebrae as well as upper and lower intervertebral disc.On the basis of models in Group B,Group C(n=6,experimental group)was installed with the novel arch cervical titanium mesh and fixed by plate and screw,and Group D(n=6,control group)was installed with traditional straight titanium mesh and fixed by plate and screw.The ranges of motion(ROMs)for 4 groups of specimens during flexion,extension,left/right lateral bending,left/right rotation under 2.0 N·m load were measured,and their three-dimensional(3D)motion stability was tested.The displacement of Group C and Group D under 200 N compression force was measured,the stiffness was calculated,and the anti settlement ability of the whole specimen was tested.Results The ROMs of Group A in all directions were smaller than those of Group B,the ROMs of Group A were larger than those of Group C,and the ROMs of Group C during flexion were smaller than those of Group D(P<0.05).The stiffness of Group C was higher than that of Group D(P<0.05).The compression displacement of Group C was smaller than that of Group D(P<0.05).Conclusions Compared with the straight titanium mesh,the novel arc titanium mesh is more consistent with the physiological curvature of cervical verebrae,and has better stability than the traditional titanium mesh during the most frequent flexion activities of cervical verebrae.Moreover,compression displacement of the novel arc titanium mesh under short-term stress is smaller than that of the straight titanium mesh,and its postoperative anti-settlement is better than that of the straight titanium mesh,which is worthy of further experiment and clinical promotion.