Study Design: 

A prospective study of in vitro animal.

Objection: 

To compare the biomechanics of cortical bone trajectory screw (CBT) and bone cement screw (BC) in an isolated porcine spinal low bone mass model.

Summary of Background Data: 

The choice of spinal fixation in patients with osteoporosis remains controversial. Is CBT better than BC? Research on this issue is lacking.

Methods: 

Ten porcine spines with 3 segments were treated with EDTA decalcification. After 8 weeks, all the models met the criteria of low bone mass. Ten specimens were randomly divided into groups, group was implanted with CBT screw (CBT group) and the other group was implanted with bone cement screw (BC group). The biomechanical material testing machine was used to compare the porcine spine activities of the two groups in flexion, extension, bending, and axial rotation, and then insertional torque, pull-out force, and anti-compression force of the 2 groups were compared. Independent sample t test was used for comparison between groups.

Results: 

Ten 3 segments of porcine spine models with low bone mass were established, and the bone mineral density of all models was lower than 0.75 g/cm². There is no difference between the CBT and BC groups in flexion, extension, bending, and axial rotation angle, P>0.05. However, there were significant differences between the 2 groups and the control group, with P＜0.01. The 2 groups significantly differed between the insertional torque (P=0.03) and the screw pull-out force (P=0.021). The anti-compression forces between the 2 groups have no significant difference between the two groups (P=0.946).

Conclusions: 

The insertional torque and pull-out force of the CBT were higher than those of the BC in the isolated low bone porcine spine model. The range of motion and anti-compression ability of the model was similar between the 2 fixation methods.

中文翻译：

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用于固定猪脊柱低骨量模型的皮质骨轨迹螺钉与骨水泥螺钉的生物力学分析

学习规划： 

一项体外动物的前瞻性研究。

异议： 

比较皮质骨轨迹螺钉(CBT) 和骨水泥螺钉(BC) 在离体猪脊柱低骨量模型中的生物力学。

背景数据摘要： 

骨质疏松症患者脊柱固定的选择仍存在争议。CBT 比 BC 好吗？缺乏对这个问题的研究。

方法： 

用 EDTA 脱钙处理 10 个 3 段猪脊柱。8周后，所有模型均符合低骨量标准。10例标本随机分组，一组植入CBT螺钉（CBT组），另一组植入骨水泥螺钉（BC组）。利用生物力学材料试验机比较两组猪脊柱的屈、伸、弯、轴旋转活动，进而比较两组的插入力矩、拔出力和抗压缩力。组间比较采用独立样本t检验。

结果： 

建立10个3节段低骨量猪脊柱模型，所有模型的骨密度均低于0.75 g/cm ²。CBT组与BC组在屈、伸、弯、轴旋转角度方面无差异，P >0.05。但2组与对照组比较差异有统计学意义，P＜0.01。两组在插入扭矩（P =0.03）和螺钉拔出力（P =0.021）之间存在显着差异。两组间的抗压缩力两组间无显着性差异（P =0.946）。

结论： 

在分离的低骨猪脊柱模型中，CBT 的插入扭矩和拉出力高于 BC。两种固定方法的模型运动范围和抗压能力相似。