Johnson G A, Tramaglini D M, Levine R E, Ohno K, Choi N Y, Woo S L
Department of Orthopaedic Surgery, University of Pittsburgh, PA 15213.
J Orthop Res. 1994 Nov;12(6):796-803. doi: 10.1002/jor.1100120607.
The tensile and viscoelastic properties of fresh-frozen, nonirradiated human patellar tendon were investigated in two groups of 15 specimens: one group was from individuals 29-50 years old and the other group was from individuals 64-93 years old. The central portion of each patella-patellar tendon-tibia complex was subjected to cyclic preconditioning, stress-relaxation, cyclic stress-relaxation, and load to failure tests. For each age group, stress-relaxation and stress-strain curves were obtained, from which percentage relaxation, ultimate tensile strength, strain at failure, modulus, and strain energy density were determined. Viscoelastic behavior was described with use of quasilinear viscoelasticity. The younger group showed a 46 +/- 9% (mean +/- SD) decrease in stress after 15 minutes, whereas the older group exhibited a 50 +/- 6% decrease. The values for ultimate tensile strength and strain at failure, respectively, were 64.7 +/- 15.0 MPa and 14 +/- 6% for the younger group and 53.6 +/- 10.0 MPa and 15 +/- 5% for the older group. Modulus values were 660 +/- 266 MPa for the younger group and 504 +/- 222 MPa for the older group. Except for ultimate tensile strength, which was 17% less for the older group than for the younger one, no statistically significant differences were found in tensile or viscoelastic properties. This study indicated that there were minimal differences in biomechanical properties of the substance of the patellar tendon between younger and older age groups.
在两组各15个样本中，对新鲜冷冻、未辐照的人髌腱的拉伸和粘弹性特性进行了研究：一组来自29至50岁的个体，另一组来自64至93岁的个体。对每个髌骨 - 髌腱 - 胫骨复合体的中央部分进行循环预处理、应力松弛、循环应力松弛和破坏载荷试验。对于每个年龄组，获得了应力松弛和应力 - 应变曲线，并由此确定了松弛百分比、极限拉伸强度、破坏应变、模量和应变能密度。使用准线性粘弹性来描述粘弹性行为。较年轻组在15分钟后应力下降了46±9%（平均值±标准差），而较年长组下降了50±6%。较年轻组的极限拉伸强度和破坏应变值分别为64.7±15.0 MPa和14±6%，较年长组分别为53.6±10.0 MPa和15±5%。较年轻组的模量值为660±266 MPa，较年长组为504±222 MPa。除了较年长组的极限拉伸强度比年轻组低17%外，在拉伸或粘弹性特性方面未发现统计学上的显著差异。这项研究表明，较年轻和较年长年龄组之间髌腱物质的生物力学特性差异极小。
