膝关节前交叉韧带与后交叉韧带粘弹性实验研究

研究了10具新鲜成人尸体膝关节前交叉韧带和后交叉韧带的拉伸力学性质和粘弹性力学性质,对前交叉韧带和后交叉韧带进行单向拉伸实验,得出了破坏载荷,强度极限、最大应变、伸长比、弹性模量.对前交叉韧带和后交叉韧带进行应力松弛,蠕变实验,得出了应力松弛、蠕变实验数据和曲线.对实验数据进行归一化处理,得出了归一化应力松弛函数,蠕变函数,以回归分析的方法处理实验数据,得出了回归系数,很好的拟合了实验曲线.实验结果表明:前交叉韧带的拉伸强度极限、最大应变等大于后交叉韧带,后交叉韧带7200s应力松弛、蠕变量小于前交叉韧带.     

前交叉韧带粘弹性特性的实验研究

目的 探讨前交叉韧带的力学性能和粘弹性行为与时间的变化规律，为研究人工韧带提供生物力学参数。方法 对正常国人新鲜尸体膝关节前交叉韧带进行系统的拉伸、应力松驰、蠕变实验，得出最大载荷、强度极限、最大应变、弹性模量等；还得出了应力松驰、蠕变实验数据和曲线，归一化应力松驰函数、蠕变函数数据和曲线。并得到7200s时的蠕变量和应力松驰量。结果 ①前交叉韧带在实验中表现出典型的松弛、蠕变现象，说明其粘弹性性质在膝关节运动中起着重要的缓冲作用。②最初600s时应力应变的变化幅度较大，之后应力缓慢下降，应变缓慢上升，前交叉韧带7200s时应力松弛量1．05Mp，蠕变量为6．82％。结论 前交叉韧带具有良好的粘弹性力学性质。其粘弹性力学行为是为了适应其所在解剖部位的功能需要。     

膝关节前交叉韧带与内侧副韧带粘弹性实验研究

目的　研究了新鲜成人尸体膝关节前交叉韧带和内侧副韧带的粘弹性力学性质，为临床提供生物力学参数依据。方法　对前交叉韧带和内侧副韧带进行应力松弛，蠕变实验。结果　对实验数据进行归一化处理，得出了归一化应力松弛函数，蠕变函数，以回归分析的方法处理实验数据，得出了回归系数和拟合曲线。结论　内侧副韧带7200s应力松弛、蠕变量小于前交叉韧带。对实验结果进行分析讨论。     

人颈椎前纵韧带生物力学特性实验研究

目的研究正常国人颈椎前纵韧带的生物力学特性．为临床提供生物力学参数。方法取正常国人8具新鲜尸体颈椎C1-C4、C4-T1不同节段前纵韧带在Shimadzu AUTOGRAPH电子万能试验机上进行单向拉伸实验研究。结果得出了前纵韧带C1～C4、C4一T1段的拉伸破坏载荷、伸长比、Lagrange张应力、Lagrange张应变、Euler应力、弹性模量等数据。对应力、应变数据以最小二乘法进行拟合，得出颈椎前纵韧带C1-C4、C4-T1段的应力应变关系表达式及曲线。结论前纵韧带C1-C4段应力大于C4-T1段，前纵韧带C1-C4、C4-T1应变差异不显著，C4-T1段前纵韧带弹性模骨大于C1-C4殷前纵韧带。     

拇指掌指关节侧副韧带粘弹性的实验研究

研究正常国人新鲜尸体的拇指掌指关节侧副韧带的粘弹性力学性质,为临床提供生物力学参数。对拇指掌指关节侧副韧带进行拉伸应力松弛、蠕变实验。得出了拇指掌指关节侧副韧带的应力松弛、蠕变数据。对实验数据进行归一化处理,得出了归一化应力松弛函数、蠕变函数及曲线。以回归分析的方法处理实验数据,得出了回归系数。表明拇指掌指关节侧副韧带为粘弹性生物材料。     

人颈椎后纵韧带黏弹性实验研究

研究了正常国人8具新鲜尸体颈椎后纵韧带C1-C4、C4-T1的黏弹性力学性质.对C1-C4、C4-T1段后纵韧带进行拉伸应力松弛、蠕变实验.得出了C1-C4、C4-T1后纵韧带的应力松弛、蠕变数据和曲线.对应力松弛、蠕变数据进行归一化处理,得出了归一化应力松弛函数蠕变函数及曲线.对实验数据进行回归分析,得出了回归系数.还对后纵韧带C1-C4段、C4-T1段试样进行单向拉伸实验,得出了后纵韧带的拉伸破坏载荷、伸长比、拉应力、拉应变等,对应力应变数据以多项式,用最小二乘法进行拟合,得出其应力应变关系公式及曲线.构建了后纵韧带的松弛函数K(λ、t)=G(t)T(e)(λ)表达式,对实验结果进行分析讨论.     

膝关节后交叉韧带损伤对侧副韧带生物力学的影响

背景：目前对膝关节后交叉韧带损伤后的研究多集中于软骨、后外侧结构及关节的松弛度等方面。 目的：观察后交叉韧带断裂对膝关节内、外侧副韧带生物力学的影响。 方法：取12具正常成人新鲜尸体膝关节标本,在200 N载荷下,测试膝关节屈曲0°,30°,60°,90°位时,内、外侧副韧带中点的应变,后将12具标本的后交叉韧带全部切断再进行相同的测试。 结果与结论：膝屈曲0°和30°位时,后交叉韧带断裂前后内、外侧副韧带中点的应变均为压应变,且差异无显著性意义 (P > 0.05);膝屈曲30°~90°位时,内侧副韧带中点的应变随着角度增加而逐渐增大;膝屈曲60°和90°位时,后交叉韧带断裂后拉应变较断裂前明显增大(P < 0.05),其中内侧副韧带中点的应变均为拉应变,而外侧副韧带中点的应变在后交叉韧带完整情况下膝屈曲60°时为压应变。说明后交叉韧带完全断裂对30°内的膝关节运动无明显影响,但是随着屈曲角度的增加,内、外侧副韧带受到的影响逐渐增大。     

胎儿臂丛神经上干粘弹性实验研究

研究了 30具新鲜胎儿尸体臂丛神经上干的拉伸力学性质和粘弹性力学性质 ,对臂丛神经上干进行单向拉伸实验 ,得出了破坏载荷、强度极限、最大应变。对臂丛神经上干进行应力松弛、蠕变实验 ,得出了应力松弛、蠕变实验数据和曲线。对实验数据进行归一化处理 ,得出了归一化应力松弛函数、蠕变函数。以回归分析的方法处理实验数据 ,得出回归系数 ,很好地拟合了实验曲线。实验结果表明 6～ 7月龄胎儿臂丛神经上干的破坏载荷、强度极限、最大应变小于 8月龄以上的胎儿。男女胎儿臂丛神经之间拉伸力学性质差异不显著 ,低月龄胎儿臂丛神经 72 0 0S应力松弛量大于高月龄组 ,蠕变量差异不显著     

国人股骨下端松质骨力学性质实验研究

对正常国人新鲜尸体股骨下端松质骨的拉伸、压缩、扭转、剪切、弯曲、冲击等力学性能进行实验研究,得出了股骨下端松质骨纵向的拉伸、压缩破坏载荷、强度极限、弹性模量,扭转破坏扭矩、扭转剪切强度极限,扭转剪切弹性模量,剪切破坏载荷、剪切强度极限,弯曲破坏载荷、弯曲强度极限,冲击功、冲击韧性指标.对松质骨的取样方法及松质骨拉伸,扭转试样固定装夹方法进行探讨.对股骨下端松质骨的力学性质进行分析讨论.     

髂股韧带与股骨头韧带黏弹性实验研究

目的 研究新鲜成人尸体髋关节髂股韧带和股骨头韧带的黏弹性力学性质,为临床提供生物力学参数.方法 取正常国人髂股韧带和股骨头韧带各10个试样进行应力松弛、蠕变实验.结果 得出了应力松弛、蠕变实验曲线,以回归分析的方法处理实验数据,得出了回归系数.结论 髂股韧带7200s应力松弛蠕变量显著大于股骨头韧带.     

Porcine anterior cruciate ligament fibroblasts are similar to cells derived from the ligamentum teres, another non-healing intra-articular ligament

Porcine ligament fibroblasts were cultured from the anterior cruciate (ACL), medial collateral (MCL), and ligamentum teres (LT). There were no apparent differences in confluent cellular morphology among the ligament cell types as evaluated by phase contrast microscopy. The proliferation rate of MCL cells from 24-120 h was significantly higher (p < 0.05) than that of cells from either the LT or the ACL. MCL cells produced more collagen and less non-collagenous protein than the LT and ACL as determined by [3H]proline incorporation. This resulted in MCL cells producing a higher percentage (37%, p < 0.05) of collagen relative to total protein than either the ACL (28%) or the LT (32%). The MCL cells produced a significantly higher percentage (34.7%, p < 0.05) of type-III collagen relative to total type-I and III collagen than either the ACL (29.2%) or the LT (29.5%). The LT and MCL cells had similar and significantly greater coverage of in vitro wounds than the ACL. This study provides the first in vitro study of the LT and demonstrates that fibroblasts from the LT and ACL, two ligaments that heal poorly, have similar in vitro characteristics, with the exception of wound healing.     

桡动脉血管生物力学性质实验研究

研究了正常国人新鲜尸体桡动脉血管的一维拉伸力学性质，得出了桡动脉血管的破坏载荷、伸长比、Lagrange张应力、Lagrange张应变、Euler应力等数据。以多颈式用最小二乘法对实验数据进行拟合，得出了桡动脉的应力——应变关系表达式及曲线。得出了一些结论。     

兔部分损伤前交叉与内侧副韧带差异环状RNA的筛选与功能分析*

目的：交叉对比兔前交叉韧带（ACL）与内侧副韧带（ MCL）部分损伤前后环状RNA表达差异,并进行功 能分析,探讨ACL 内源性修复障碍可能的分子机制。方法：对兔ACL 及MCL 组织环状RNA建库测序,筛选符 合标准的差异环状RNA,并用qRT-PCR 验证,对筛选的差异环状RNA进行京都基因和基因组百科全书（KEGG） 和基因本体论（GO）分析,并构建其ceRNA网络。结果：各组中共筛选出308 个差异环状RNA,GO 和KEGG分 析表明,ACL 与MCL 损伤后的差异环状RNA在血管生成、炎症反应、细胞增殖与凋亡及mRNA 转录与蛋白翻译 方面均存在较大差异。ACL 与MCL 损伤后的ceRNA网络差异显著。结论：环状RNA在ACL 与MCL 损伤后的差 异表达谱中存在明显差异,为进一步研究ACL 损伤内源性修复障碍的机制提供了新思路。     

Cultures of ligament fibroblasts in fibrin matrix gel

The cellular properties of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) fibroblasts have been analyzed in a three-dimensional fibrin matrix gel (FMG) system. The MCL fibroblasts proliferated significantly faster than ACL fibroblasts in 10% fetal bovine serum (FBS). FMG contraction resembles soft-tissue wound contraction. Transforming growth factor-beta1 (TGF-beta1) (5 ng/ml) caused a significantly faster rate of FMG contraction than control (0.5% FBS) in both ACL and MCL fibroblasts. Unlike the cells in 10% FBS, this faster rate of FMG contraction was achieved without increasing the initial cell number. In the FMG, the MCL fibroblasts demonstrated significantly higher collagen synthesis per cell than ACL fibroblasts between the days 2 and 6 of culture. These differences in cellular properties of the ACL and MCL fibroblasts that were observed in vitro may explain the differences in the healing potential of these ligaments in vivo.     

Novel method for the quantitative assessment of cell migration: a study on the motility of rabbit anterior cruciate (ACL) and medial collateral ligament (MCL) cells

A novel method of quantitating cell migration has been proposed for the potential utilization of tissue engineered scaffolds. Applying Alt's conservation law to describe the motion of first passage ACL and MCL cells, we have developed a quantitative method to assess innate differences in the motility of cells from these two ligamentous tissues. In this study, first passage ACL and MCL cells were cultured from four mature New Zealand white rabbits. One side of the cell monolayer was scraped completely away to create a wound model. The cell moved into the cell-free area, and cell density profiles were analyzed at 6 h and 12 h. Values of the random motility coefficient (mu) were then estimated by curve fitting the 6 h and 12 h data to a mathematical model, derived from the conservation law of cell flux. During 6 h of incubation in medium supplemented with 1% FBS, MCL cells (mu(MCL) = 4.63 +/- 0.65 X 10(-6) mm(2)/sec) were significantly (p < 0.05) more mobile than ACL cells (mu(ACL) = 2.51 +/- 0.31 X 10(-6) mm(2)/sec). At 12 h, the MCL cells also appeared to move faster (mu(ACL) = 4.39 +/- 0.63 X 10(-6) mm(2)/sec, mu(MCL) = 6.59 +/- 1.47 X 10(-6) mm(2)/sec), but the difference was not statistically significant (p = 0.18). Exposure of the cells to growth factors PDGF-BB or bFGF for 6 h had no significant effect on the migration of the ACL and MCL cells. However, exposure of the ACL cells (p < 0.05) and the MCL cells (p = 0.19) to 1 ng/mL of PDGFBB for 12 h enhanced their migration. Incubation with a high concentration (100 ng/mL) of PDGF-BB or bFGF at concentrations tested (1 or 100 ng/mL) for 12 h, produced little or no migratory stimulation on these ligament cells. Our findings support the previous qualitative observations made by numerous investigators. The novel methodology developed in this study may provide a basis for tissue engineering, and the results may be applied to tissue reconstruction techniques of the knee ligaments.     

Cultures of Ligament Fibroblasts in Fibrin Matrix Gel

The cellular properties of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) fibroblasts have been analyzed in a three-dimensional fibrin matrix gel (FMG) system. The MCL fibroblasts proliferated significantly faster than ACL fibroblasts in 10% fetal bovine serum (FBS). FMG contraction resembles soft-tissue wound contraction. Transforming growth factor- &#103 1 (TGF- &#103 1) (5 ng/ml) caused a significantly faster rate of FMG contraction than control (0.5% FBS) in both ACL and MCL fibroblasts. Unlike the cells in 10% FBS, this faster rate of FMG contraction was achieved without increasing the initial cell number. In the FMG, the MCL fibroblasts demonstrated significantly higher collagen synthesis per cell than ACL fibroblasts between the days 2 and 6 of culture. These differences in properties of the ACL and MCL fibroblasts that were observed in vitro may explain the differences in the healing potential of these ligaments in vivo.     

Collagenase production by rabbit ligaments and tendon

Three periarticular connective tissues from normal rabbits were examined for collagenolytic activity. Enzyme activity was secreted by cultures of anterior cruciate ligament (ACL), medial collateral ligament (MCL) and patellar tendon (PT). A lag period of six days or more was often observed prior to the detection of active collagenase. We attributed this to the presence of an excess of inhibitor in the early days of culture. We quantitated the amount of enzyme and inhibitor produced in 13 days. The levels of collagenase in the ACL and MCL were comparable. The PT, however, consistently secreted more enzyme than the two periarticular (ACL and MCL) ligaments. The reaction products were analyzed for all three collagenases and compared to those generated by the rabbit skin enzyme. We observed the characteristic TCA and TCB collagen fragments for MCL and PT enzymes. Collagen cleavage by the ACL cultures resulted in a product with a molecular weight intermediate between the alpha 2 chain and the TCA piece. These data suggest that quantitative and qualitative differences exist in the ability of these similar connective tissues to degrade collagen.     

自噬在兔部分损伤前交叉韧带和内侧副韧带中的差异*

目的：确定兔前交叉韧带和内侧副韧带部分损伤后自噬的存在,并比较损伤后不同时间两者之间自噬的表 达差异,探讨其愈合能力差异与自噬的关系。方法： 3 月龄健康雄性新西兰大白兔18 只,随机选取3 只作为对照 组,其余兔建立前交叉韧带和内侧副韧带部分损伤模型, 随机分为5 组,各组分别在造模后3 d、1 周、2 周、4 周、 6 周取材。H-E 染色观察损伤部位形态学变化,透射电镜观察损伤部位超微结构变化,免疫印迹检测自噬相关蛋 白Beclin 1、LC3Ⅱ/Ⅰ、p62 表达水平,RT-PCR 检测自噬相关基因Beclin 1、ATG-5 mRNA表达水平。结果：在 部分损伤后3 d、1 周、2 周、4 周、6 周5 个时间点,前交叉韧带和内侧副韧带均未表现出明显的愈合趋势,观察 到自噬小体的存在。与对照组相比,自噬相关蛋白Beclin 1、LC3Ⅱ/Ⅰ、p62 在前交叉韧带中的高表达更为显著, 在内侧副韧带中的表达更早恢复至正常水平,并继续降低;自噬相关基因ATG-5、Beclin 1 在前交叉韧带中始终 处于高表达状态,峰值出现在1 周,内侧副韧带高表达峰值出现在2 周,此后逐渐恢复至正常水平。结论： 兔前 交叉韧带、内侧副韧带部分损伤后自噬相关因子的表达随时间推移,总体呈现先升高后降低的变化趋势,损伤后 不同时间点前交叉韧带、内侧副韧带中自噬的表达存在明显差异,推测前交叉韧带损伤后自噬的过度激活可能导 致其内源性修复障碍。     

Changes in Gene Expression of Matrix Constituents with Respect to Passage of Ligament and Tendon Fibroblasts

Trauma to the knee joint often results in injury to one or more supporting soft tissue structures, such as the medial collateral (MCL) and anterior cruciate (ACL) ligaments. Also, a portion of the patellar tendon (PT) is frequently used as a replacement graft for the ACL, resulting in a PT defect. The healing responses of these tissues are dramatically different and range from spontaneous healing to little or no healing. Studies have suggested that native cell behavior could be responsible for differences in healing potential. However, it is difficult to make comparisons as the reported results are based on different cellular passages which could have a dramatic effect on their potential to form healing tissues. Therefore, the objective of this study was to quantify the gene expression of collagen and other matrix constituents of fibroblasts from the MCL, ACL, and PT to document how they change with cell passage. We hypothesized that MCL fibroblasts would possess higher potential for matrix production through passages than ACL and PT cells because the MCL mounts a robust healing response unlike the ACL and PT. These differences in matrix expression would be dependent on passage because at earlier passages all cells would mostly be proliferating while at later passages they would tend to become senescent. Cells were isolated from the MCL, ACL, and PT of three rats and passaged a total of five times (Passage 1 to Passage 5). Using real time RT-PCR, expression of all genes of interest (Collagen Type I (ligament/tendon’s main matrix constituent), Collagen Type III, Fibronectin, Metalloprotease-13 [MMP-13], and Tissue Inhibitor of Metallopreotease-1 [TIMP-1]) were quantitatively assessed. It was found that cell number for all three fibroblast types remained high from Passage 1 to Passage 5. There was a statistically significant increase in Collagen Type I of rat MCL fibroblasts throughout passage (p < 0.05). This was evident in the higher relative abundance (to GAPDH) at Passages 3 and 4 (14.5 ± 2.2 fold and 15.3 ± 6.9 fold, respectively) than at Passage 1 (3.3 ± 2.6 fold) (p < 0.05). On the other hand, Collagen Type I expression for ACL and PT fibroblasts were lower than that of MCL fibroblasts and remained at 2.5 ± 2.0 fold and 1.7 ± 0.8 fold, respectively. Interestingly, the gene expressions of Collagen Type III, Fibronectin, MMP-13, and TIMP-1 for MCL, ACL, and PT fibroblasts were all relatively constant throughout passage and were not significantly different from one another. The findings of this study indicate that passage does affect the Collagen Type I gene expression of rat MCL fibroblasts and further show that for in vitro ligament tissue engineering efforts, MCL fibroblasts have a more robust potential for ligament remodeling and repair due to the increase in collagen gene expression.     

Proprioception in the ACL-ruptured knee: the contribution of the medial collateral ligament and patellar ligament. An in vivo experimental study in the cat

In the absence of anterior cruciate ligament (ACL), secondary restraints such as menisci, ligaments, and tendons restrict anterior knee laxity. Strain detection at these sites could define the contribution of this alternative signalling system to knee proprioception after ACL injury. The hypothesis in this study questions if measurements of anterior tibial translation (ATT) from surface strain gauges on the insertions of the medial collateral ligament (MCL) and the patellar tendon (PT) are sufficiently sensitive and specific to differentiate normal, stable knees from acutely unstable knees due to ACL section. Twelve cats received miniaturized strain gauges on the surface of MCL and PT distal insertions. A purpose-made receiver transformed into measurements any voltage variation obtained during passive knee flexion-extension and anterior tibial translation manoeuvres. Variables under evaluation included first peak latency, normalized amplitude, and slope of voltage along time. Femorotibial displacements were video recorded, digitized, and used as the ATT reference. The proposed system detected significant changes in the slope of the voltage/time signal, with higher specificity and sensitivity during ATT after experimental ACL section. Changes were not significant during flexion or extension. It was found that a pattern of earlier and more intense strain in MCL and PT distal insertions was found during ATT in the ACL deficient knee. Enhanced pattern recognition learning from these structures could be a future target for proprioceptive training after ACL injury.