实验动物臂丛神经的拉伸力学特性

背景:臂丛神经损伤缝合吻接术有必要了解臂丛神经拉伸力学特性.目的:对大鼠臂丛神经进行拉伸实验,观察其臂丛神经的拉伸力学特性,为临床提供拉伸力学特性参数.方法:取SD大鼠C6～7臂丛神经40个,随机分为正常对照组20个,模拟臂丛神经损伤吻接组20个,对模拟臂丛神经损伤吻接组以手术刀在标本中间切开再缝合吻接离断标本.在电子万能试验机上以5 mm/min的实验速度对2组标本进行拉伸实验,以多项式用最小二乘法处理实验数据.拉伸实验速度为5 mm/min.观察大鼠臂丛神经拉伸最大载荷、最大位移、最大应变、最大应力和应力-应变曲线.结果与结论:模拟臂丛神经损伤吻接组大鼠臂丛神经拉伸最大载荷为(1.050±0.135)N、最大位移为(3.090±0.356)mm、最大应变为(61.860±7.252)%、最大应力为(5 095±0.647)GPa,正常对照组最大载荷、最大应力大于模拟丛神经损伤吻接组(P<0.05).模拟臂丛神经损伤吻接组最大位移和最大应变大于正常对照组(P<0.05).拉伸应力-应变曲线是以指数关系变化的.结果显示2组臂丛神经标本具有不同的拉伸力学特性.     

髂股韧带与股骨头韧带的拉伸力学性质

背景:髂骨韧带和股骨头韧带损伤,通常要通过外科重建韧带的功能来达到韧带的平衡和稳定,如果韧带损伤面积大则需要人工韧带置换.目的:比较骼骨韧带和股骨头韧带的拉伸力学性质,为韧带缝合和研制人工韧带材料提供生物力学参数.设计、时间及地点:观察性实验,于2007-08-12/15在吉林大学力学实验中心完成.材料:髂股韧带和股骨头韧带各20个试样,长16 mm、宽8 mm、厚1.6～1.8 mm,由白求恩医科大学解剖教研室提供.方法:将标本两端装夹于软组织夹具中,夹具装夹于电子万能试验机上、下夹头内,驱动机器,以5 mm/min的速度对试样施加载荷,直至断裂.主要观察指标:标本的最大载荷、最大应力、最大应变和应力-应变曲线.结果:髂骨韧带组最大载荷为(240.40±29.81)N,最大应力为(17.65±2.26)MPa,最大应变为(16.44±2.48)%,弹性模量为(264.6±27.3)MPa;股骨头韧带组最大载衙为(216.15±20.00)N,最大应力为(15.88±1.47)MPa,最大应变为(14.40±1.28)%,弹性模量为(252.8±23.0)MPa.股骨头韧带的拉伸最大载荷、最大应力、最大应变、弹性模量小于髂骨韧带(P<0.05).结论:髂骨韧带各项力学性能指标显著大于股骨头韧带.     

正常与病态眼角膜拉伸力学的特性

背景:角膜移植和人工角膜替代物等研究有必要了解正常和病态眼角膜的拉伸力学特性,以往的研究对象多为动物眼角膜和正常人眼角膜的拉伸力学特性,病态眼角膜的拉伸力学特性鲜有报道.目的:比较正常和病态眼角膜的拉伸力学性质.方法:正常人尸体眼角膜和病态(眼角膜移植患者眼角膜)眼角膜各10个,在电子万能试验机上进行拉伸实验.模拟人体温在(36.5±0.5)℃的温度下,以5 mm/min的实验速度对试样施加载荷,以最小二乘法处理实验数据,拟合应力-应变曲线.结果与结论:正常对照组眼角膜最大载荷、最大应力、最大应变、最大位移均大于病态组(P＜0.05).说明正常与病态眼角膜具有不同的拉伸力学特性,病态眼角膜的拉伸力学特性发生改变.     

膝关节后交叉韧带的拉伸力学性质

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1.0～2.0 h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) = 0.000 40-0.016 11ε 0.228 16ε2 -0.417 53ε3 0.804 75ε4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.     

骨性关节炎动物模型外侧副韧带的拉伸力学性质

背景:了解骨性关节炎时膝关节外侧副韧带的拉伸力学性质,对预防和治疗骨性关节炎非常有必要,但这方面的报道不多.目的:建立骨性关节炎动物模型,比较正常和骨性关节炎动物膝关节外侧副韧带的拉伸力学性能指标,提出骨性关节炎对外侧副韧带拉伸力学性质影响的定性定量化参考数值.设计、时间及地点:随机对照实验,于2008-11-20/30在吉林大学力学实验中心完成.材料:6月龄雄性SD大鼠20只,随机分成正常对照10只,模型组10只.方法:模型组大鼠复制骨性关节炎模型.在日本岛津电子万能试验机上对正常和病态组各10个试样进行拉伸实验.拉伸实验的速度为5mm/min.以多项式用最小二乘法处理实验数据.主要观察指标:拉伸最大载荷、最大位移、最大应力、最大应变、应力-应变曲线.结果:正常对照组最大载荷为(12.754±2.795)N,最大应力为(27.681±5.832)MPa,最大位移为(2.754±0.707)mm,最大应变为(11.679±2.373)%;模型组最大载荷为(7.183±1.817)N,最大应力为(16.162±3.403)MPa,最大位移为(1.827±0.768)mm,最大应变为(8.019±2.811)%.正常对照组各项拉伸性能指标显著大于模型组(P＜0.05).结论:骨性关节炎时,可以使膝关节拉伸最大载荷、最大位移、最大应力、最大应变降低、对膝关节外侧副韧带拉伸力学性能及应力松弛性具有一定影响.     

正常国人升主动脉、腹主动脉、肾动脉血管的松弛函数及力学性质

背景:主动脉损伤都需要进行吻接修复。国内外学者对主动脉血管的粘弹性力学性质已作了一些研究。作者未检索到关于人主动脉单向拉伸破坏实验及构建松弛函数的报道。目的:对正常国人急性外伤致死的成人新鲜尸体升主动脉、腹主动脉、肾动脉进行一维拉伸试验,测量分析血管的力学性质。设计、时间及地点:以函数为描述方式的对比分析,实验于2007-08-10/20在吉林大学力学实验中心完成。材料:实验标本取自正常国人因急性外伤至死的5具男性尸体的升主动脉、腹主动脉、肾动脉,由白求恩医科大学解剖教研室提供,年龄23～30岁。方法:死后1h之内解剖取死者出升主动脉、腹主动脉、肾动脉,将标本沿纵向切成长25mm的试样共26个。以一维拉伸的方法对升主动脉、腹主动脉、肾动脉进行拉伸实验。在模拟正常人体温在(36.5±0.5)℃的温度场下进行,以20mm/min的速度对试样施加拉应力,试样破坏后,计算机自动输出应力-应变曲线和数据。主要观察指标:①升主动脉、腹主动脉、肾动脉一维拉伸实验结果。②升主动脉、腹主动脉、肾动脉一维拉伸实验中的应力-应变关系。③升主动脉、腹主动脉、肾动脉松弛函数构建。结果:①拉伸实验结果显示,肾动脉的破坏应力大于腹主动脉和升主动脉(P<0.05),腹主动脉的伸长比和应变大于肾动脉和升主动脉(P<0.05)。②应力松弛蠕变试验结果表明:肾动脉和腹主动脉7200s应力松弛量比较接近,升主动脉7200s应力松弛量小于腹主动脉和肾动脉,差异显著(P<0.05)。腹主动脉7200s蠕变量大于肾动脉大于升主动脉,差异显著(P<0.05)。根据冯元桢教授的准线性理论得出升主动脉、腹主动脉、肾动脉松弛函数κ(λt)=G(t)T(e)(λ)的表达式。结论:肾动脉的最大应力大于腹主动脉及升主动脉,腹主动脉伸长比和应变大于肾动脉及升主动脉。主动脉升部、腹部、肾部随其生理解剖位置不同具有不同的力学性质。     

动脉粥样硬化模型动物脑血管的拉伸力学特性

背景:脑动脉粥样硬化和脑出血的防治有必要了解正常和动脑粥样硬化模型大鼠大脑中动脉的力学特性,但以往的研究对象多为正常人尸体与正常动物脑动脉的力学特性.目的:比较正常和动脉粥样硬化动物模型大脑中动脉的拉伸力学特性.方法:SD大鼠随机分为正常对照组和模型组.模型组大鼠建立动脉粥样硬化模型.取2组大鼠的大脑中动脉以电子万能试验机对其进行5 mm/min拉伸载荷实验,观察2组大鼠脑动脉最大载荷、最大位移、最大应力以及最大应变差异及血管应力-应变关系.结果与结论:动脉粥样硬化大鼠脑动脉血管拉伸最大载荷、最大应力、最大位移及最大应变均较正常大鼠明显降低(P<0.05),大鼠脑动脉血管应力-应变曲线是以指数关系变化的.因此,说明动脉粥样硬化模型大鼠大脑中动脉和正常对照组大鼠大脑中动脉具有不同的拉伸力学特性,脑动脉粥样硬化大鼠动脉血管不能像正常大鼠脑血管一样再作较大的伸展.     

模拟股骨干骨折接骨板固定应变电测量

背景:研究接骨板固定后的应力、应变分布规律,设计符合生物力学原理的接骨板是当前急待解决的课题.目的:测量模拟股骨骨折以接骨板固定后各测点的应变值,以期为设计新型接骨板提供力学参数.设计、时间及地点:单因素设计,实验于2007-07/11在吉林大学力学试验中心完成.材料:新鲜尸体股骨标本由白求恩医科大学解剖教研室提供,均为男性.死亡后2 h之内解剖尸体,取下双侧股骨共4个标本,以生理盐水浸湿的纱布包裹标本,装入塑料袋中,密封后置于-20 ℃冰箱内保存.实验前取出标本在室温下解冻后以线锯在股骨中段据开制成骨折模型,以6孔接骨板进行固定,在接骨板的12个测点贴上电阻应变片.方法:分别将贴片干燥后的标本置于电子万能试验机的工作台上,以2 mm/min的实验速度,施加1 kN载荷,通过YJ-22型静态电阻应变仪测出各测点的应变值.主要观察指标:股骨承受1 kN载荷时各测点应变值.结果:最大应力、应变发生在骨干中部骨折断口和螺钉孔附近,应变值为(1 069.0±22.4) ×10-6,应力值为(17.68±2.21) MPa;最小应力、应变发生在骨干上部骨折远端,应变值为(498.0±19.6) ×10-6,应力值为(8.21±1.36) MPa.结论:以尽可能少的螺钉固定钢板,螺钉的直径要尽量达到最小以避免骨折断口和螺钉孔附近部位的应力集中.     

弯曲力学性质:青年与老年尸体肋骨的比较

背景:骨质疏松、骨重建、骨再造等都需要了解青年和老年尸体肋骨的弯曲力学特性.以往的研究多以单独青年尸体或单独老年尸体肋骨为观察对象,而有关青年和老年尸体肋骨弯曲力学特性的研究报道极少.目的:对正常国人青年和老年新鲜尸体肋骨进行弯曲实验,分析肋骨的弯曲力学性质,确定老年尸体肋骨和青年尸体肋骨是否具有不同的弯曲力学性质.方法:实验标本取自4具正常国人男性新鲜尸体,年龄分别为20,25,70,75岁,由白求恩医科大学解剖教研室提供.人死亡后1 h之内解剖取出死者肋骨标本,将标本沿纵向切成长45mm的试样.以三点弯曲的方法进行弯曲实验,检测肋骨最大载荷、弯矩、应力、应变及宏观断口形貌.结果与结论:青年组肋骨最大载荷、最大弯矩、最大应力、最大应变均显著大于老年组(P＜0.05).肋骨弯曲断口多数为横断口,少数为斜断口.青年组肋骨骨皮质较厚,老年组肋骨骨皮质较薄,呈现出骨质疏松形态,提示青年组肋骨和老年组肋骨具有不同的弯曲力学特性,老年组试样由于骨质疏松导致弯曲力学特性发生改变.     

膝关节后交叉韧带的拉伸力学性质

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＋0．22816ε^2-0．41753ε^3＋0．80475ε^4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。     

运动性关节软骨损伤修复材料的选择及其生物力学特征

背景：关节软骨是无血管、淋巴管和神经的组织,通常情况下软骨细胞不能进行有丝分裂,这导致自身修复能力有限。生理负荷下,关节软骨经常处在应力环境中。根据软骨自身的结构和特点,作为人工软骨的替代材料应具有良好的生物力学性能。目的：总结运动性关节软骨损伤修复材料的应用进展及其生物替代材料的生物力学特征。方法：以＂关节软骨,生物材料,生物力学＂为中文关键词,以＂tissue enginneering,articular cartilage,scaffold material,biomechanics＂为英文关键词,采用计算机检索中国期刊全文数据库、PubMed数据库1993-01/2010-10相关文章。纳入与运动有关的关节软骨损伤修复、目前常用于修复关节软骨损伤的生物材料以及生物替代材料的生物力学特征研究文章;排除重复研究或Meta分析类文章。以20篇文献为主重点对运动性关节软骨缺损修复材料的生物力学特征进行讨论。结果与结论：关节软骨是一种各向异性、非均质、具有黏弹性并充满液体的可渗透物质,具有独特的力学性能。损伤的关节软骨在生物力学方面均与原来的软骨不同,且极易退变。骨软骨柱移植力学性能近期效果最佳;脱细胞软骨基质、小肠黏膜下基质具有一定的力学强度;普通聚乙烯醇水凝胶的最大缺陷是力学性能的不足;聚乙烯醇材料其良好的柔韧性和高弹性能,具有与人关节软骨相似的力学性能;n-HA浆料与聚酰胺66在溶剂中复合,无论在力学性能还是化学组成上都与自然骨相似。提示在众多关节软骨替代材料中,无论是人工合成材料、天然材料、复合材料其生物力学性能各有不同,且目前还无法再造与天然生成的软骨具有相同力学性能的软骨组织。     

A constitutive study of the age-dependent mechanical behaviour of deep articular cartilage: Model construction and simulated failure

The tensile properties of deep articular cartilage of the human femoral head have been simulated using a model based on the expected mechanical behaviour of an electrostatically cross-linked network of collagen fibrils. Articular cartilage requires a model incorporating two types of interactions, referred to as type I and type II, which differ in the amount of energy required to bring about their mechanical failure. This modified two-population (MTP) model is shown to accurately simulate the experimental tensile behaviour of 14 specimens of deep articular cartilage. Also, the MTP model simulates a failure behaviour which appears to be comparable to the actual experimental fracture of the articular cartilage specimens. A reduction in the fracture stress of the deep articular cartilage specimens with age can be interpreted through age-related changes which occur in the values of the parameters of the MTP model. This shows that the younger tissues derive their superior tensile properties through an optimum structural arrangement which is associated with a high proportion of binding equivalent to the type I interaction in the tissue model. A decline in the tensile properties with age occurs as the tissue structure falls from its optimal configuration as the proportion of type II interactions increases. Such changes may predispose the articular cartilage to the mechanical damage and deterioration which leads to the osteoarthritic degeneration of a joint.

Relevance

An understanding of the process of osteoarthritic degeneration requires a knowledge of the relationship between the biochemical composition and mechanical behaviour of articular cartilage. An approach is developed to examine this relationship in order to gain insight into the ultrastructural basis of the mechanical weakening of articular cartilage with age.     

Indentation stiffness does not discriminate between normal and degraded articular cartilage

BACKGROUND: Relative indentation characteristics are commonly used for distinguishing between normal healthy and degraded cartilage. The application of this parameter in surgical decision making and an appreciation of articular cartilage biomechanics has prompted us to hypothesise that it is difficult to define a reference stiffness to characterise normal articular cartilage. METHODS: This hypothesis is tested for validity by carrying out biomechanical indentation of articular cartilage samples that are characterised as visually normal and degraded relative to proteoglycan depletion and collagen disruption. Compressive loading was applied at known strain rates to visually normal, artificially degraded and naturally osteoarthritic articular cartilage and observing the trends of their stress-strain and stiffness characteristics. FINDINGS: While our results demonstrated a 25% depreciation in the stiffness of individual samples after proteoglycan depletion, they also showed that when compared to the stiffness of normal samples only 17% lie outside the range of the stress-strain behaviour of normal samples. INTERPRETATION: We conclude that the extent of the variability in the properties of normal samples, and the degree of overlap (81%) of the biomechanical properties of normal and degraded matrices demonstrate that indentation data cannot form an accurate basis for distinguishing normal from abnormal articular cartilage samples with consequences for the application of this mechanical process in the clinical environment.     

Mechanical characteristics of articular cartilage bonds

BACKGROUND: Sutures for adaptation of articular cartilage are used in arthritis therapy techniques. However, little is known about the mechanical functionality of these sutures. The objective of the present work was to compare the mechanical properties of articular cartilage bonds either generated by suture, or, alternatively, by chemical cross-linking of the opposing surfaces or in vitro integrative repair of cartilage blocks. METHODS: Bonding was achieved by suture in varying numbers, positions and orientations, by surface cross-linking using carbodiimide in combination with pepsin or guanidine (immediate bonding), or by cultivation for 14 days, either with or without testosterone. The mechanical properties of the cartilage bonds were measured under tensile loading. FINDINGS: Suture led to the highest maximal load at failure and by far to the highest strain and lowest stiffness of the bonded samples. Immediate bonding by chemical cross-linking in combination with pepsin led to a low force at failure, but the highest stiffness, as compared to all other groups. Cultivation in the presence of testosterone led to a higher force at failure and a higher strain than chemical cross-linking. INTERPRETATION: Suture technique for bonding of cartilage surfaces leads to a very elastic adaptation which allows synovial fluid flow in between the interface of cartilage wounds. Long-term bonding of cartilage wounds would be counteracted by a fluid flow through the interface during motion of the joint. Immediate bonding of cartilage wounds by chemical cross-linking reagents might be a useful alternative tool. Even more promising, with regard to the mechanical properties, appears to be integrative repair of cartilage blocks stimulated by testosterone.     

关节炎和力学因素

关节炎和力学因素的关系可涉及病因学、病理学、诊断学和治疗学。本文简述了关节软骨和滑液的生物力学及关节运动学和动力学与关节炎的关系,涉及了应力和一氧化氮的作用,解释了关节源性肌抑制,分析了关节炎康复治疗中力学原理的应用。该文提出,力是关节炎发生、发展的原因之一,关节炎又可导致关节结构的力学性能改变。治疗关节炎时,必须运用生物力学原理。     

Mechanical properties of collagen fascicles from stress-shielded patellar tendons in the rabbit.

OBJECTIVE: To know the effects of stress shielding applied to the patellar tendon on the collagen fascicles.DESIGN: The mechanical properties of collagen fascicles obtained from stress-shielded patellar tendons were compared to those of collagen fascicles from non-treated patellar tendons and those of stress-shielded bulk patellar tendons in the rabbit.BACKGROUND: Effects of stress deprivation and stress enhancement on the mechanical properties of knee joint tendons and ligaments have been extensively studied in various animal models. However, the roles of such substructural components as collagen fascicles in the remodeling of tendons and ligaments have not been studied well.METHOD: Tensile and viscoelastic properties of collagen fascicles obtained from the rabbit patellar tendons which were completely stress-shielded for 1 to 3 weeks by a special method developed by the authors were determined using a micro tensile tester.RESULTS: Stress shielding significantly decreased the tangent modulus, tensile strength, and strain at failure of collagen fascicles. However, these changes were much smaller than those observed in bulk tendons. The relaxation of stress-shielded collagen fascicles was greater than that of non-treated ones.CONCLUSIONS: Ground substance and mechanical interaction between collagen fascicles have important roles in the remodeling of tendons and ligaments.RELEVANCE: Knowledge of the role of such substructural components as collagen fascicles in the remodeling of tendons and ligaments is essential not only to the basic biomechanics of knee joint tendons and ligaments but also to the development of their reconstruction methods using autografts.     

Development of an artificial articular cartilage

We have attempted to develop an artificial articular cartilage on the basis of a new viewpoint of joint biomechanics in which lubrication and load-bearing mechanisms of natural and artificial joints are compared. We investigated poly(vinyl alcohol)-hydrogel (PVA-H) which has been recognized as a rubber-like gel and have improved the mechanical properties of this gel through a new synthetic process. In this article we report the biocompatibility and various mechanical properties of the new, improved PVA-H from the aspect of its usefulness as artificial articular cartilage. As regards the lubrication, we measured the change of thickness and fluid pressure of the gap formed between a glass plate and the specimen under loading and found that the PVA-H had a thicker fluid film under higher pressure than polyethylene (PE). The momentary stress transmitted through the specimen revealed that PVA-H had a lower peak stress and a longer duration of sustained stress than PE, suggesting a better damping effect. The wear factor of PVA-H was approximately five times as large as that of PE. Histological findings of the articular cartilage and synovial membranes around the PVA-H implanted for 8-52 weeks showed neither inflammatory nor degenerative changes. The PVA-H artificial articular cartilage could be attached to the underlying bone using an osteochondral composite material. Although there remain still some problems to solve, PVA-H seems to be a very interesting and promising material which meets the requirements of artificial articular cartilage.     

Mechanical properties of nasal fascia and periosteum

OBJECTIVE: To determine under which layer the silicone implants should be inserted into, the biomechanical properties of fascia and periosteum were investigated. DESIGN: Biomechanical testing of cadaveric tissues. BACKGROUND: In silicone augmentation rhinoplasty, most complications are closely related to the depth of implant and the mechanical character of the tissue surrounding the implant. METHODS: Biomechanical properties of human nasal periosteum and fascia were studied, including tensile strength, stress-strain relationship and stress relaxation under uniaxial elongation.Result. Although with less failure strain, the periosteum has more tensile strength than fascia. The slope of the linear part of stress-strain curve of the periosteum is bigger than that of fascia, which indicates the periosteum is stiffer than fascia. The stress-relaxation slope of periosteum is smaller than that of fascia. CONCLUSION: In the view of biomechanics, the periosteum is thicker, stronger and stiffer than fascia. Under periosteum the silicone implants are easier to be fixed at desired position, thus periosteum is more suitable for covering silicone implants. RELEVANCE: The periosteum is more suitable than fascia for covering silicone implants in augmentation rhinoplasty.     

Age and gender related changes in biomechanical properties of healthy human costal cartilage

BACKGROUND AND AIMS: For repairing the ear malformation, it is recommended in China to use the over than 10-years-old rib cartilage. However, according to our clinical experience, a better post-operation effect can be found using about the 7-years-old cartilage for the operation. To shape a harvested costal cartilage and to perform it on the transplant site depend on the mechanical properties of the costal cartilage. Hence, the aim of this study is to investigate the age and gender-related biomechanical properties of the human costal cartilage. METHODS: Human costal cartilages were harvested from 25 female and 45 male donors of 5-25 years old after auricular reconstructive surgery. The specimens were divided into six groups: children (5-10 years), adolescent (11-17 years) and adult (18-25 years), respectively, in males and females. Tensile strength, stress-strain relationship, stress relaxation and creep were tested by using a material testing machine. FINDINGS: The biomechanical properties of costal cartilage are donor age and gender related. The children group has the highest tensile strengths (P<0.01) in both male and female groups. The male group relaxed and crept more than that of the female group in all three age groups (P<0.01). INTERPRETATION: These findings provide a further support for the potential age acting on the human costal cartilage. The adolescent has the lowest strength, this could be a reason that compared to using the children costal cartilage, the bigger distortion happened after using the adolescent costal cartilage in the auricular reconstruction operation.