膝关节后交叉韧带的拉伸力学性质

Tensile mechanical properties of knee posterior cruciate ligament

目的:后交叉韧带在保持关节面的生理压力方面起着重要的作用。实验观察了新鲜成人尸体膝关节后交叉韧带的拉伸力学性质,拟为人工韧带材料的研制提供生物力学实验参数。方法:实验于2005-06/2006-06在吉林大学力学实验中心完成。实验所用10个标本均由北华大学解剖教研室提供,年龄20～30岁。标本于死者死亡后1.0～2.0h解剖取下后交叉韧带,每个标本切取2个试样,共20个试样,将试样夹持在自制的软组织专用夹具上,将夹具装在电子万能试验机上、下夹头内。驱动机器对试样施加拉应力,直至试样断裂。结果:得出拉伸最大载荷为(364.8±78.8)N、应力为(19.19±4.12)MPa、应变为(18.6±2.0)%,弹性模量为(267.5±35.4)MPa。对实验数据以多项式进行拟合,得出了后交叉韧带应力应变关系表达式如下:σ(ε)=0.00040-0.01611ε+0.22816ε2-0.41753ε3+0.80475ε4结论:后交叉韧带具有良好的拉伸力学性能,其为黏弹性材料。

AIM： Posterior cruciate ligament plays a key role in maintaining the biological pressure of knee joints. This study researched the tensile mechanical properties of knee posterior cruciate ligament in fresh cadavers, so as to provide biomechanical parameters for designing the artificial ligament materials. METHODS： The experiment was completed from June 2005 to June 2006 in the Mechanical Experimental Center of Jilin University, Ten specimens aged 20-30 years were provided by the Anatomical Research Center, Beihua University. Posterior cruciate ligaments were harvested from these specimens within postmortem 1.0-2.0 hours, and each specimen was cut into two samples. Totally 20 samples were clipped in the homemade fixture, which was dedicated for soft tissues, and then the fixture was installed in the electronic universal testing machine, within the chuck. We imposed tensile stress on the sample-driven machines until the specimen fracture occurred. RESULTS： The maximal tensile load was （364.8±78.8） N, the stress was （19.19 ± 4.12） MPa, the strain was （18.6 ± 2.0）%, and the modulus of elasticity was （267.5 ± 35.4） MPa, Other experimental data were conducted to a polynomial fitting, and the stress-strain relationship of posterior cruciate ligament can be expressed according to the formula： σ （ ε ） = 0.000 40-0.016 11ε ＋ 0.228 16ε^2 - 0.417 53 ε^3 ＋0.80475 ε^4 CONCLUSION： Posterior cruciate ligament as a viscoelastic material, has good tensile mechanical properties.