RABBIT MEDIAL COLLATERAL LIGAMENT SCAR WEAKNESS IS ASSOCIATED WITH DECREASED COLLAGEN PYRIDINOLINE CROSS-LINK DENSITY
RABBIT MEDIAL COLLATERAL LIGAMENT SCAR WEAKNESS IS ASSOCIATED WITH DECREASED COLLAGEN PYRIDINOLINE CROSS-LINK DENSITY
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DOI：
10.1002/jor.1100130203
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发表时间：
1995-03-01
影响因子：
2.8
通讯作者：
SHRIVE, N
中科院分区：
文献类型：
--
作者：
FRANK, C;MCDONALD, D;SHRIVE, N
本研究旨在量化家兔愈合内侧副韧带中材料强度与胶原浓度和吡啶啉胶原交联密度之间的潜在相关性，并将这些参数与正常韧带的参数进行比较。对24只成年（12月龄）新西兰白色家兔的右后肢内侧副韧带进行标准化的4 mm中间物质“间隙”损伤。在术后3周、6周、14周或40周的时间间隔内，每组6只动物被处死，并对股骨-内侧副韧带-胫骨复合体进行机械拉伸试验，直至失效。在机械测试之后，评估韧带的失效部位的羟脯氨酸和羟赖氨酰吡啶啉的浓度。另外9只家兔作为年龄匹配的正常对照。在愈合的韧带中，在不到14周的时间内达到正常的胶原蛋白浓度，但羟基赖氨酰吡啶啉交联密度仍然很低，在愈合40周后仅为对照值的45%。同样，机械值仍远低于对照组。单独对瘢痕组织数据的线性回归分析显示，羟脯氨酸浓度与材料强度之间存在中等强度的正相关性（r（2）= 0.51，p = 0.0001），但交联密度与瘢痕组织强度之间无相关性。在瘢痕组织的弹性模量和生化变量之间获得了类似的相关模式，但r（2）值较低。当包括对照数据时，逐步回归的结果显示交联密度和材料强度之间存在非常高的正相关性（r（2）= 0.83，p < 0.0001），判别分析表明交联密度是组成员关系的最佳分类器。结合羟脯氨酸浓度，交联值在90%的时间内正确识别愈合间隔和组。这些结果表明，尽管胶原蛋白浓度在确定愈合的内侧副韧带的早期材料行为方面肯定起着更重要的作用，但瘢痕组织中胶原蛋白的交联密度降低可能为家兔中愈合的内侧副韧带与正常韧带相比随时间推移的机械劣效性提供更具体的解释。
This study was carried out to quantify the potential associations between material strength and both collagen concentration and pyridinoline collagen crosslink density in the healing medial collateral ligament of the rabbit and to compare these parameters with those of normal ligaments. The right hindlimbs of 24 skeletally mature (12-month-old) New Zealand White rabbits were subjected to a standardized 4 mm midsubstance ''gap'' injury to the medial collateral ligament. The animals were killed in groups of six at postoperative intervals of 3, 6, 14, or 40 weeks, and the femur-medial collateral ligament-tibia complexes were mechanically tested in tension to failure. Subsequent to mechanical testing, the failure sites of the ligaments were assessed for concentrations of hydroxyproline and hydroxylysyl pyridinoline. Nine additional rabbits served as age-matched normal controls. In healing ligaments, normal collagen concentrations were reached in less than 14 weeks, but the hydroxylysyl pyridinoline crosslink densities remained low and were only 45% of the control values after 40 weeks of healing. Similarly, mechanical values remained much less than the controls. Linear regression analysis of data on scar tissue alone showed a moderately strong positive correlation between hydroxyproline concentration and material strength (r(2) = 0.51, p = 0.0001) but no correlation between crosslink density and strength of scar tissue. A similar pattern of correlation was obtained between the elastic modulus of the scar tissue and the biochemical variables, but the r(2) values were lower. When control data were included, the results of stepwise regression showed a very high positive correlation between crosslink density and material strength (r(2) = 0.83, p < 0.0001) and discriminant analysis demonstrated crosslink density to be the best classifier of group membership. Combined with hydroxyproline concentration, crosslink values correctly identified healing interval and group 90% of the time. These results suggest that although collagen concentration definitely plays a more important role in determining the early material behaviour of healing medial collateral ligaments, reduced crosslink density in collagen in scar tissue may offer a more specific explanation for the mechanical inferiority, in the rabbit, of healing medial collateral ligaments compared with normal ligaments over time.