三种内固定治疗锁骨中外1/3骨折的生物力学研究

Study on biomechanics of three kinds of internal fixations for external 1/3 fracture of clavicle

目的对经皮穿针治疗锁骨骨折的生物力学性能进行测试,并与解剖钢板和记忆合金在锁骨中外1/3骨折内固定中的生物力学性能进行比较,为临床提供科学依据。方法取16具成人尸体标本。随机取出尸体锁骨标本(左、右)共32具,并剔除标本上附着的肌肉,保持锁骨的完整性,将标本随机分成正常组、克氏针组、六孔钢板组、记忆合金组(每组8个锁骨样本量)。然后进行三点弯曲、扭转、拉伸中的生物力学测试,记录测定数据并进行统计学分析。结果①三点弯曲实验:弯曲极限载荷及极限强度实验,克氏针组与六孔钢板组及记忆合金组比较差异无统计学意义(P>0.05);②扭转实验:克氏针组最大扭矩、最大扭角及最大扭转刚度与六孔钢板组和记忆合金组比较差异有统计学意义(P<0.01);③拉伸试验:克氏针组最大抗拉伸载荷与六孔钢板组和记忆合金组比较差异有统计学意义(P<0.01)。结论从生物力学方面分析,克氏针在拉伸和扭转生物力学方面较六孔钢板和记忆合金弱,但在三点弯曲实验与前两者相当,不失为一种较为理想的内固定材料。而从AO观点来看,六孔钢板和记忆合金钢板是锁骨骨折的理想内固定方法。

Objective To study the biomeehanics of three kinds of internal fixations for external 1/3 fracture of clavicle. Methods 16 adult corpse specimens were chosen and gain 32 clavicle samples. They were divided into normal group, K-wire fixation group, anatomical plate fixation group and shape memory alloy group, 8 samples in every group. Then biomechanical testing of three point bending, torsion test, tensile test were used. The data were recorded and analyzed. Results ①Three point bending test showed that there was no significant difference among K-wire fixation group, anatomical plate fixation group and shape memory alloy group. ②Torsion test shown that there was difference of the maximal torque, maximal twist angle and the torsional stiffness between K-wire fixation group and anatomical plate fixation group,shape memory alloy group. ③The tensile test shown that there was significant difference of tensile bond strengths between K-wire fixation group and anatomical plate fixation group, shape memory alloy group. Conclusion In the point of biomechanics, kirschner wire is weaker than natomical plate and shape memory alloy in the torsion test and tensile test, while it is almost the same as the other two material In the three point bending test. It is an idea material of internal fixation. In the point of AO, natomical plate and shape memory alloy are the ideal methods for fixation of clavicular fracture.