爱惜邦线和钢丝治疗尺骨鹰嘴横行骨折的生物力学研究

Biomechanical study of ETHIBOND and stainless steel wire for the fixation of transverse olecranon fractures

目的:比较5号爱惜邦线(ETHIBOND,聚酯不可吸收缝合线)与7号单股钢丝治疗尺骨鹰嘴横行骨折的生物力学稳定性。方法:采用3D打印技术制备20例尺骨鹰嘴横行骨折模型,分为爱惜邦线组和钢丝组,每组10例,对骨折模型进行克氏针张力带固定;测量骨折断端间的压力、500次疲劳试验后骨折断端的移位,以及静态牵拉试验中弹性模量、断端分离(1 mm和2 mm)时所需载荷、内固定断裂时的极限载荷和移位。结果:爱惜邦线组和钢丝组在疲劳试验后均未出现内固定失败,但钢丝组每50个循环次数时最小载荷(10 N)对应的骨折断端的移位均小于爱惜邦线组(P<0.05),同时钢丝组骨折固定后断端间的压力、静态牵拉试验中内固定的弹性模量、断端分离时所需载荷、内固定断裂时的极限载荷和移位均大于前者(P<0.05)。结论:爱惜邦线和钢丝在治疗尺骨鹰嘴横行骨折时均能提供良好的固定,但钢丝具有更好的生物力学稳定性。

Objective： To compare the biomechanical stability of No. 5 ETHIBOND（polyester un-absorbable suture） with single strand No. 7 stainless steel wire in the treatment of olecranon fracture. Methods： Twenty olecranon transverse fracture models were prepared using 3 D printing technology and were divided into Ethibond group and steel wire group with 10 models in each group. The models were fixed with K-wire tension band fixation technique. Then the pressures in the fracture gaps,the fracture displacement in fatigue test with 500 cycles,the elastic modulus,the required load for fracture distraction（1 mm and 2 mm）,the ultimate load and displacement for breakage of internal fixation in the static stretching test were measured. Results： No internal fixation failure was observed either in Ethibond group or in steel wire group after the fatigue test. However,the displacement of the fracture fragments was significantly larger in Ethibond group than that in the steel wire group for each 50 cycles with minimal 10 N load during fatigue test,while the elastic modulus,the required load for fracture distraction,the ultimate load and displacement for breakage of internal fixation in the static stretching test were all significantly larger in the steel wire group（P 〈 0. 05）. Conclusion： Both No. 5 ETHIBOND and single strand No. 7 stainless steel wire can provide sufficient fixation for the treatment of olecranon fracture,but the single strand No. 7 stainless steel wire shows a better biomechanical stability.