Liu Yaoyao, Xu Jianzhong, Sun Dong, Luo Fei, Zhang Zehua, Dai Fei
Department of Spine Surgery, Daping Hospital, The Third Military Medical University, Chongqing, 400042, People's Republic of China.
Department of Orthopedics, Southwest Hospital, The Third Military Medical University, Chongqing, 404100, People's Republic of China.
J Biomed Mater Res B Appl Biomater. 2016 Jul;104(5):960-7. doi: 10.1002/jbm.b.33424. Epub 2015 May 15.
The objectives of this study were to investigate the safety and biomechanical stability of a polymethylmethacrylate (PMMA)-augmented bone cement-injectable cannulated pedicle screw (CICPS) in cancellous bone model, and to analyze the stress distribution at the screw-cement-bone interface. The OMEGA cannulated pedicle screw (OPS) and conventional pedicle screw (CPS) were used as control groups. Safety of the CICPS was evaluated by the static bending and bending fatigue tests. Biomechanical stability was analyzed by the maximum axial pullout strength and maximum torque tests. Stress distribution at the screw-cement-bone interface was analyzed by the finite element (FE) method. The CICPS and CPS produced statistically similar values for bending stiffness, bending structural stiffness, and bending yield moment. The maximum pullout force was 53.47 ± 8.65 N in CPS group, compared to 130.82 ± 7.32 N and 175.45 ± 43.01 N in the PMMA-augmented OPS and CICPS groups, respectively (p < 0.05). The CICPS had a significantly greater torque than the OPS and CPS. The FE model did not reveal excessive stress at the screw-cement-bone interface in the CICPS group. In conclusion, PMMA-augmentation with CICPS may be a potentially useful method to increase the stability of pedicle screws in patients with osteoporosis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 960-967, 2016.
本研究的目的是在松质骨模型中研究聚甲基丙烯酸甲酯（PMMA）增强的骨水泥可注射空心椎弓根螺钉（CICPS）的安全性和生物力学稳定性，并分析螺钉-骨水泥-骨界面的应力分布。将OMEGA空心椎弓根螺钉（OPS）和传统椎弓根螺钉（CPS）用作对照组。通过静态弯曲和弯曲疲劳试验评估CICPS的安全性。通过最大轴向拔出强度和最大扭矩试验分析生物力学稳定性。采用有限元（FE）方法分析螺钉-骨水泥-骨界面的应力分布。CICPS和CPS在弯曲刚度、弯曲结构刚度和弯曲屈服力矩方面产生的统计学值相似。CPS组的最大拔出力为53.47±8.65 N，相比之下，PMMA增强的OPS组和CICPS组分别为130.82±7.32 N和175.45±43.01 N（p<0.05）。CICPS的扭矩明显大于OPS和CPS。有限元模型未显示CICPS组螺钉-骨水泥-骨界面存在过大应力。总之，CICPS联合PMMA增强可能是增加骨质疏松症患者椎弓根螺钉稳定性的一种潜在有用方法。©2015威利期刊公司。《生物医学材料研究杂志》B部分：应用生物材料，104B：960 - 967，2016年。
