Ultrastructural determinants of murine achilles tendon strength during healing
Ultrastructural determinants of murine achilles tendon strength during healing
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DOI：
10.1080/03008200390248452
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发表时间：
2003-10-01
影响因子：
2.9
通讯作者：
Mikic, B
中科院分区：
文献类型：
--
作者：
Battaglia, TC;Clark, RT;Mikic, B
肌腱强度在生长发育过程中建立和损伤后恢复的机制尚未完全了解，可能是复杂的多因素过程。几项研究探讨了肌腱和韧带在生长和成熟过程中的力学行为和超微结构特征之间的关系，表明胶原纤维直径与肌腱强度密切相关。由于肌肉骨骼组织的发育和修复过程之间的相似性，愈合过程中肌腱强度的增加可能与原纤维超微结构参数的增加有关，如原纤维大小，数密度和面积分数。在这项研究中，我们比较了小鼠跟腱在不同的时间点后，肌腱切断术与假手术的控制，在拉伸试验失败，并检查肌腱用电子显微镜，以评估胶原纤维超微结构。我们发现，在跟腱切断术后6周内，纤维平均直径仍显着小于假侧直径的2-3倍。尽管持续小的原纤维尺寸，增加数密度导致原纤维面积分数逐渐增加。生物力学强度没有达到完整的肌腱，直到5和7周之间的某个时间，大约相同的时间段时，原纤维面积分数开始接近假手术值。这些数据表明，参数以外的胶原纤维的大小是最负责的肌腱强度增加愈合过程中。
The mechanisms by which tendon strength is established during growth and development and restored following injury are not completely understood and are likely to be complex, multifactorial processes. Several studies examining the relationship between mechanical behavior and ultrastructural characteristics of tendons and ligaments during growth and maturation suggest that collagen fibril diameter is strongly correlated with tendon strength. Because of the similarities between development and repair processes of musculoskeletal tissues, increases in tendon strength during healing may be related to increases in fibril ultrastructural parameters such as fibril size, numerical density, and area fraction. In this study, we compared murine Achilles tendons at various time points after tenotomy with sham-operated controls in tensile tests to failure and examined tendons using electron microscopy to assess collagen fibril ultrastructure. We found that in the 6-week period following Achilles tenotomy, fibril mean diameter remained significantly smaller than sham-side diameter by a factor of 2-3. Despite the persistently small fibril size, increasing numerical density resulted in a gradual increase in fibril area fraction. Biomechanical strength did not reach that of intact tendons until some time between 5 and 7 weeks, approximately the same time period when fibril area fraction began to approach sham values. These data suggest that parameters other than collagen fibril size are most responsible for increased tendon strength during healing.