 机器翻译字幕，仅供参考： now we have seen how callus formation 现在我们已经看到愈伤组织的形成 heals a bone by indirect bone healing 是如何通过间接骨愈合来治愈骨骼的， let's look at the tissue which is involved 让我们看看 in indirect bone healing when we have relative stability 当我们具有相对稳定性时参与间接骨愈合的组织 now i have a little gadget here which demonstrates a normal fracture which has 现在我有一个小工具，它展示了一个正常骨折，其 different gap widths in the static situation 间隙宽度不同 静态情况 this is a bone which will heal 这是一块会愈合的骨头 there is one cell in this small gap there are two cells in the medium gap 在这个小间隙中有一个细胞 在中等间隙中有两个细胞， and three cells in the wide gap now 在宽间隙中有三个细胞现在 this can heal well but in an indirect type of bone healing with 这可以很好地愈合，但是在一种具有相对稳定性的间接骨愈合中， relative stability we have micro movement i will 我们有 微运动 我将 demonstrate micro movement by sliding this part back and forth and 通过来回滑动这部分来演示微运动， now you can see how the strain differs from gap width to gap width 现在您可以看到顶部的间隙宽度与间隙宽度 on the top you see a very small gap and if the strain is too large 之间的应变有何不同，您会看到一个非常小的间隙，如果应变太大， this cell will probably break and will not contribute to bone healing 该电池可能会破裂并且不会促进骨愈合， but in this type of a fracture we have other parts 但在这种类型的骨折中，我们还有其他 which will heal well because the strain is distributed 部分可以很好地愈合，因为应变分布 among very many cells and each cell can withstand the strain 在非常多的细胞和每个细胞中 l 可以承受 of the micro movement which is also needed for bone healing 骨骼愈合所需的微运动的压力， so in the end it really doesn't matter if one or two cells break 因此最终是否有一个或两个细胞破裂并不重要， because with time the callus will encompass 因为随着时间的推移，愈伤组织将覆盖 all of this area and will heal the bone 所有该区域并愈合骨骼 another example for parent strain theory is demonstrated by this foam rubber 另一个例子这个泡沫橡胶装置证明了父应变理论 device this is also a demonstration of relative 这也是相对稳定性的证明 stability this is a bone which encompasses 这是一块骨头， a large gap on the left this demonstrates an a-type fracture 左侧有一个大间隙这证明了 a 型骨折 smaller gaps in the middle this demonstrates a b-type fracture 中间的间隙较小 这证明了 b 型骨折 and multiple gaps on the right side this demonstrates a 右侧有多个间隙，这表明 multi-fragmented type fracture which we consider to be a seed 多碎片型骨折，我们认为是种子 type fracture as you can see 型 as i put distraction on this foam the gap on the left opens up now if we only have a few cells in this 骨折 在这个 gap they are destroyed 间隙中它们被破坏了， because the strain in this gap is much too high 因为这个间隙 in the middle the strain becomes less and the chances that 中的应变在中间太高了，应变变得更小，并且 i can get indirect bone healing are much higher 我可以在r上获得间接骨愈合的机会要高得多 on the right side you see that the gaps do not really open up that much 右边你会看到间隙并没有真正打开那么多， so we have a strain which is distributed among all of these fragments that we 所以我们有一个应变分布在我们拥有的所有这些碎片中 have and this actually enhances bone healing ，这实际上增强了骨愈合， because we have micro movement between individual fracture fragments 因为我们在单个骨折碎片之间有微小的运动 the same model demonstrates bending loads so when i put bending loads on the 相同的模型展示了弯曲因此，当我再次在组织上施加弯曲载荷时， tissue again you can see on the left we have a gap which actually widens when we 您可以在左侧看到我们有一个间隙，当我们有弯曲载荷时实际上会变宽， have a bending load so that the cells in this large gap will not contribute to 因此这个大间隙中的细胞不会有助于 bone healing the cells in the middle of the large gap probably will because the 骨骼愈合中间的细胞大的间隙可能会因为 gap is narrowing in the bottom we have compression the compression may be so 底部的间隙变窄我们有压缩压缩可能 high that some of the cells are destroyed 太高以至于一些细胞被破坏 the same goes for the three gaps in the middle which 中间的三个间隙也是如此，这 demonstrate the b type fracture these type of gaps are usually bridged 表明b型断裂这些类型的间隙是 通常 by callus since there is no absolute stability we cannot expect direct bone 由愈伤组织桥接，因为没有绝对的稳定性，我们不能指望直接的骨 healing and on the right the bending load does not really alter 愈合，并且在右侧，弯曲负荷并没有真正改变 the type of healing that we get the bone will heal very rapidly 愈合的类型 我们得到的骨头会很快愈合 this is an experiment on plate mechanics now if we consider 这是一个关于板力学的实验如果我们 that plate fixation is actually a composite beam system because we 认为板固定实际上是一个复合梁系统因为我们 attach the plate to the bone we can consider different stiffnesses 将板固定在骨头上我们可以考虑不同的刚度 i would like for you just to test the different stiffnesses that we have here 我希望你只是为了 测试我们这里的不同刚度， beginning with the stiffness of the bone and the plate 首先是骨骼和板的刚度 and the bone plus the plate and then the composite plate plus bone plus screws ，骨骼加上板，然后是复合板加上骨骼加上螺钉 which one is the stiffest now ，哪个是最硬的，现在 take this into your hand and move it again 把它拿到你的手中，再次移动它 and see what you can feel ，看看 你能感觉到 do you feel the shear between the plate and the bone 什么你感觉到板和骨头 there is shear and when we apply screws 之间的剪切有剪切，当我们使用螺钉时， we are actually counteracting the shear 我们实际上是在抵消剪切 and this increases the stiffness because now we have a composite beam system ，这增加了刚度，因为现在我们有一个复合梁系统 let's look at this small experiment here now again 现在让我们看看这个小实验再一次， we have a number of beams that are very elastic as you can see 我们有一些非常有弹性的梁，正如你所看到的 and when we push these beams or give them a bending load ，当我们推动这些梁或给它们一个弯曲载荷时， we see that there is a shear between each and every beam 我们看到中间有一个剪切力每根梁都 okay we can see this by seeing the difference 可以，我们可以通过看到 in the heights of these little markings here there is no stability among the 这些小标记的高度差异来看到这一点 beams if i lock these beams with this little locking bolt 如果我用这个小锁紧螺栓锁定这些梁，那么梁之间就不稳定， now i put a bending load on this composite 现在我在这个复合材料上施加弯曲载荷， you see what happens i cannot bend this into an arch this 你看 发生了什么我不能把它弯曲成一个拱形这 actually goes into an s form this is a very very stable form because 实际上变成了一个s形式这是一个非常稳定的形式因为 you see i have more or less reduced the shear 你看到我或多或少地减少了剪切 to a point where you have a high stability here just by putting in one 到你在这里有一个高稳定性的点只需放 little locking bolt 一点 锁定螺栓 let's turn to this little experiment here you see a plate fixation on a 让我们转向这个小实验在这里你会看到一个 generic bone each of these two models represents a 普通骨骼上的钢板固定 这两个模型中的每一个都代表一个 transverse fracture we will define that the top 横向骨折我们将定义这个结构的顶部 of this construction is the tension side now 是受拉侧现在 let us try bending 让我们尝试 from the tension side what happens 从张力侧弯曲 we can sense that there is compression on the transverse fracture if you place the plate on the compression side of the bone and now you 如果你把钢板放在骨头的压力侧，我们可以感觉到横向骨折有受压，现在你 put a bending load from here what happens with the gap 从这里施加弯曲载荷会发生什么 the gap actually opens so this is an unstable situation 间隙实际打开的间隙，所以这是一个不稳定的情况 would you like to try this ，你想试试这个， so the gap does not close if the plate is 所以如果板 on the compression side during bending moments 在弯曲力矩期间处于受压侧，间隙不会关闭 now these two objects represent a fracture which has a large gap 现在这两个对象代表一个有大间隙的裂缝 or a multi-fragmented type of fracture now if we place 或一个 现在是多碎片类型的骨折 如果我们 the plate on the tension side as opposed to the compression side 将板放在受拉侧而不是受压侧， we can now put a bending moment on it and why don't you try this 我们现在可以在其上施加弯矩，为什么不尝试 put a bending moment on both and see if there's a big difference 在两者上都施加弯矩，看看是否有 很大的不同 there's not much difference is there we have combination 没有太大的区别是我们 in the diaphysis here and it really doesn't matter where you put the plate 在这里有骨干组合，你把钢板放在哪里并不重要， but as the 但随着 bone heals you want the plate on the tension side 骨骼愈合，你希望钢板在张力侧， so now let us discuss the results of this exercise and what you can learn 所以现在让我们讨论这个练习的结果 以及你能学到什么 |
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