两种固定器固定脊柱骨折脱位的生物力学分析

背景:胸腰椎脊柱骨折脱位的治疗方法主要是通过手术以内、外固定器械进行复位固定.脊柱骨折脱位固定治疗是国内外学者们研究的重要课题.目的:从生物力学角度对临床应用治疗脊柱骨折脱位的椎弓根钉和钢板固定器进行定量分析,为临床提供力学参数.方法:在日本岛津电子万能试验机上对模拟L_1椎体骨折脱位以钢板固定和以椎弓根钉固定标本进行前屈、后伸、压缩、扭转实验,实验速度为5 mm/min,在扭转试验机上进行扭转实验,实验速度为0.05(°)/s.以统计分析和配对t检验方法处理实验数据.结果与结论:实验结果表明各组压缩实验结果差异无显著性意义(P>0.05).椎弓根钉固定组左、右扭转角度小于钢板固定组(P<0.05).椎弓根钉固定组前屈、后伸位移小于钢板固定组(P<0.05).提示骨折脱位后钢板内固定效果不如椎弓根固定,而锥弓根钉内固定有利于促进骨折愈合和复位,所以椎弓根钉固定是一种较好的内固定方法.

Biomechanical analysis of two fixation methods in treating spine fracture and dislocation

BACKGROUND:Thoracic or lumbar spine fracture and dislocation mainly treated by internal/external fixation devices with surgical methods.Fixation methods in treating spine fracture and dislocation is an important subject for scholars.OBJECTIVE:To quantitative analyze the treatment of spinal fracture and dislocation using pedicle screw and plate fixation,and to provide mechanical parameters for clinical application.METHODS:Shimadzu electronic universal testing machine was used to simulate L_1 lumbar fracture and dislocation treated by plate fixation and pedicle screw fixations,specimens were underwent flexion,extension,compression,as well as torsion tests,with speed of 5 mm/min.The torsion test was performed on the torsion machine with speed of 0.05 (°) / s.All the experimental data were analyzed by statistical analysis and paired t test.RESULTS AND CONCLUSION:The results demonstrated that the outcomes of compression test had no significant differences between 2 groups (P>0.05).The left and right torsion angle of the pedicle screw fixation group was smaller than that of the plate fixation group (P<0.05),and the flexion and extension displacements was smaller in the pedicle screw fixation group than in the plate fixation group (P<0.05).It suggested that plate fixation is worse than pedicle screw fixation,while pedicle screw fixation is conductive to bone healing,thus,pedicle screw fixation is a better internal fixation device.