垂直应力作用下骨盆旋转位时的生物力学研究

目的运用生物力学实验技术在扭转实验机上对垂直并旋转不稳定型骨盆骨折的生物力学特点及其发病机制进行了初步探讨。方法选取正常成人骨盆实验标本12具,模拟正常人在单纯垂直应力作用下、单纯旋转应力作用下、垂直并旋转应力作用下、不同工况时,骶髂关节、髋臼、耻骨支等骨盆关键部位的受力状况,用应变仪获得骨盆各关键点的主应变、主方向,以及骨盆的极限应力及极限扭矩。结果①单纯垂直压缩状态下,在骨盆环结构中,骶髂关节附近(尤以骶骨侧)承载压、拉应变最大,耻骨、坐骨支最小。②单纯扭转状态时,骨盆各点所受拉应变明显增加,尤以耻骨上支处增加最为明显;各实验点中以左骶髂关节髂骨侧所受拉应变最大,而左骶髂关节骶骨侧所受压应变最大,且应变值随着扭矩增加而增加。③骨盆标本在单纯垂直应力状态下的屈服点载荷均值为2860N,极限载荷3600N;在单纯扭转状态下的屈服点扭矩均值为12.5°,极限扭矩15°。④无论在垂直应力或扭转应力下,髋臼前柱应变值均明显高于后柱。⑤耻骨支仅参与维持骨盆环的旋转稳定性,而骶髂关节对于维持骨盆环的垂直及旋转稳定性均至关重要。结论①垂直应力作用下骨盆旋转位时各实验点应变值远高于单纯垂直应力状态或单纯扭转状态。②骶髂关节等后环结构对于维持骨盆环在垂直及旋转应力下骨盆环的稳定性至关重要。

Biomechanical study on pelvis rotation under the vertical stress

Objective To study the biomechanical feature and pathogenesis of the pelvis rotation position under the vertical stress with torsion testing machine.Methods Twelve samples of vertical unstable pelvic fracture model were established.The sacroiliac joint,acetabulum,pubic ramus and other key parts of pelvis were measured under the condition of simple vertical stress,the stress under simple rotation,vertical and rotational stress by simulation of healthy individual.The principal strain,principal directions of p...