内锥及外锥形椎弓根螺钉的生物力学研究

Experimental Pullout Testing and Comparison of Variable in Transpedicular Screw Fixation

目的 评价内锥及外锥形椎弓根螺钉固定的生物力学特点。方法 两具成人新鲜腰椎标本 ,选取六个完整椎体 ,随机在两侧椎弓根内分别打入两种形状的椎弓根螺钉 ,在试验机上做椎弓根螺钉拔出实验。结果 外锥形椎弓根螺钉在正常椎弓根内的最大拨出力为 996 17± 5 4 6 9N ,内锥形椎弓根螺钉在正常椎弓根内的最大拔出力为 6 6 7 17± 2 4 74N ,差异有显著性意义。

Objective To evaluate two types of pedicle screw fixation strength.Methods Six whole vertebral bodies were choosed from two adult fresh lumbar specimen. Two types of pedicle screw were implanted into the two side pedicle unilaterally. The screws were pulled out from the vertrbrae in the WD 10A experimental machine.Results Pullout force of pedical screw in inner prick was 667.17±24.74N and in outer prick was 996.17±54.69N. The results were satistically significant.Conclusion The design of outer prick screw thread would improve the pull out force.