可调套式栓钉治疗胫骨平台骨折的生物力学研究

A Biomechanical Study of Schatzker-Tibial Plateau Fracture Stabilized by New Adjustable Stud

目的比较新型可调套式栓钉与普通拉力螺钉治疗SchatzkerⅠ型胫骨平台骨折的生物力学特性。方法选用成人胫骨标本8对,男性4对,女性4对;年龄53~69岁,平均年龄59.4岁。建立SchatzkerⅠ型胫骨平台骨折模型并分为两组,每组均包含4具左侧胫骨和4具右侧胫骨,两组模型骨密度平均值比较无统计学差异。A组（实验组n=8）应用新型可调套式栓钉进行固定,B组（对照组n=8）使用普通拉力螺钉固定。利用力学测定仪器先以0.05 cm/s的速度对每组标本施加垂直压力至400N,测量各标本的塑性沉降距离,在400N的压力下以5Hz的频率对标本做重复压力测试,每具标本循环1 000次,测量循环结束后的沉降距离记录（即动态抗压能力）。最后对标本持续加压直至标本损毁,测量其极限抗压值。结果两组模型在400N压力下的塑性沉降平均值和末次循环后的沉降距离比较均有统计学差异,A组结果优于B组（P〈0.001）。两组模型的极限抗压值比较无统计学差异（P〉0.05）。结论新型可调套式栓钉是一种治疗SchatzkerⅠ型胫骨平台骨折更为有效的新方法,具有更好的抗压和骨折稳定的效果。

Objective To compare the biomechanical p roperties in the Schatzker-Ⅰ tibial p lateau fracture model stabilized either by the new adjustable stud or by the lag screw.Methods A Schatzker-Ⅰ tibial p lateau fracture was created in 8 pairs of adult human cadaver tibiae divided into 2 groups to make sure each proup include 4 left and 4 right tibiae the average bone density between the two group has no statistically significant differences.Group A（n=8）was stabilized by the new adjustable stud.Group B（n=8）received the fixation by the lag screw.The plastic deflection was measured at the levels of vertical pressure of400 N.Then the ispecimens were axially cyclically loaded to 1 000 cycles to determine dynamic stability,and finally loaded to failure to measure the overall failure strengths.Results There was significant difference between two fixation methods for average p lastic deflection on the vertical pressure of 400N and after the last cycle（P 0.001）.The results of group A are better than group B.The overall failure strengths showed no significant difference between two groups（P0.05）.Conclusion New adjustable stud is a new kind of method for the therapy of Schatzker-Ⅰ tibial plateau fracture and has better stability against pressure.