摘要
目的评估颈椎椎体螺钉（4．0mm）失效后，常规颈椎椎体补救螺钉（4．5mm）的生物力学性能。方法取4具新鲜尸体颈椎标本（c3一C7），游离出20个完整颈椎椎骨。在椎体左右两侧分别置人直径4．0mm的颈椎椎体螺钉，测量螺钉的最大旋入扭矩。在生物力学实验机上行最大轴向拔f{j力实验，记录最大轴向拔出力。沿原进钉点、原钉道置人直径4．5mm的补救螺钉，测量补救螺钉置入时的最大扭矩，置入后在生物力学实验机上进行最大轴向拔出力实验。比较颈椎椎体螺钉与补救螺钉的最大旋入扭矩以及最大轴向拔出力，分析最大旋入扭矩与最大轴向拔出力的关系。结果颈椎椎体螺钉组平均最大轴向拔出力为（380．01±161．07）N，补救螺钉组平均最大轴向拔Ⅲ力为（169．63±77．20）N，两者差异有统计学意义（P〈0．01）。颈椎椎体螺钉组置入的最大扭矩平均值为（2．64±0．88）kgf／cm，补救螺钉组置入的最大扭矩平均值为（1．50±0．36）kgf／cm，两者筹异有统计学意义（P〈0．01）。颈椎椎体螺钉组置人的最大扭矩与最大轴向拔出力显著相关（r=0．768，P〈0．01），补救螺钉组置人的最大扭矩与最大轴向拔出力显著相关（r=0．534，P〈0．01）。结论直径4．0mm的颈椎椎体螺钉失效后，通过原钉道置人直径4．5mm的补救螺钉并不能提供足够的生物力学稳定性。
Objective To evaluate the biomechanical consequence of revision screw for failed cer- vical vertebrae screw fixation. Methods Twenty cervical vertebral levels from four fresh - frozen cadaveric cervical spine specimens （ C3 - C7 ） were instrumented bilaterally with 4.0 - mm vertebrae screws, and in- sertional torque （IT） was measured with each revolution. Screws were tensile loaded to failure ＂in- line＂ with the screw axis, and pullout strength （POS） tested. Then 4.5 - mm revision screws were reinserted a- long the same trajectory, and IT was measured with each revolution, and pullout strength POS tested. The POS and IT results of the 4. 0 - mm vertebrae screws, and 4. 5 - mm revision screws groups were com- pared. Results There was significant difference in screw POS between 4. 0 - rata titanium vertebrae screws group and 4.5 -mm titanium revision screws group [ （380.01 ± 161.07） N vs. （ 169.63 ±77.20） N, re- spectively; P 〈 0. 01 ]. There was significant difference in IT between 4. 0 -mm titanium vertebrae screws group （INI） [ （ 2. 64 ± 0. 88 ） kgf/cm ] and 4. 5 mm revision screws group [ （ 1.50 ± 0. 36 ） kgf/cm 1 （ P 〈0. 01 ）. The 4. 0 - mm titanium vertebrae screws and 4. 5 - mta titanium revision screws in the cervi- cal spine had significant correlations between IT and POS （ r = 0. 768, P 〈 0. 01 ; r = 0. 534, P 〈 0. 01 ）. Conclusion 4. 5 - mta revision screw fixation cannot provide enough biomeehanieal fixation for failed 4. 0 - mm cervical vertebrae screws fixation.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2016年第3期724-726,共3页
Chinese Journal of Experimental Surgery
基金
浙江省卫计委医药卫生科学研究基金（2015KYA202）
关键词
椎体螺钉
颈椎
生物力学
Vertebral screw
Cervical spine
Biotaechanies
