不同灭菌法对深冻及冻干人骨拉力螺钉生物力学性能的影响

Effect of sterilization on the biomechanical character of deep－ frozen and deep－ frozen dehydrated lag－ screw made with human bone

目的 测试不同灭菌法对深冻及冻干人骨拉力螺钉 (lag－ screw made with human bone， LHB）的剪切和扭转生物力学性能的影响。方法 取青壮年新鲜尸体标本的股骨干，经深冻后制成 48枚直径为 5 mm的 LHB，随机等分成 6组 (A～ F)。分别作如下处理 :A组 :单纯深冻； B组 :深冻＋环氧乙烷 (ethylene oxide, EO)熏蒸； C组 :深冻＋ 60Co照射； D组 :深冻＋冻干； E组 :深冻＋冻干＋ EO熏蒸； F组 :深冻＋冻干＋ 60Co照射。在生物材料测试系统上分别对 LHB的光杆部及螺纹部行剪切强度测试，再行扭转强度测试。结果 A～ F组 LHB光杆部及螺纹部的剪切强度分别为 1 140、 1 099、 897、 1 226、 1 112、 891及 386、 491、 309、 484、 414、 336 N，螺纹部 C组与 B、 D组，光杆部 C、 F组与 A、 B、 D、 E组间的差异有显著性意义 (P 0.05)。结论 中小剂量 60Co照射使深冻及冻干的 LHB的剪切强度明显下降，而对扭转强度影响较小；其余处理方法对 LHB生物力学性能影响不大。

Objective To study the effect of sterilization on the character of shear and torsion of deep－ frozen and deep－ frozen dehydrated lag－ screw made with human bone(LHB). Methods After deep－ frozen, specimens from diaphysis of femurs from fresh adult cadavers were procured and made into 48 LHBs with diameters of 5 mm. The LHBs were divided into 6 groups randomly, and were treated as follows: group A: deep－ frozen only, group B: sterilized by ethylene oxide(EO), group C: radiated by 60Co, group D: deep－ frozen dehydrated, group E: deep－ frozen dehydrated＋ sterilized by EO, group F: deep－ frozen dehydrated＋ radiated by 60Co. Then, the LHBs were tested on MTS to determine the shear strength in the part with thread and the part without, following the torsion strength test. Results The shear strength in the part without thread and the part with thread in group A－ F was 1 140, 1 099, 897, 1 226, 1 112, 891 and 386, 491, 309, 484, 414, 336 N respectively. There were significant differences both between group C and B, D at the parts with thread (P