Effects of Static Compression With Different Loading Magnitudes and Durations on the Intervertebral Disc An In Vivo Rat-Tail Study
Effects of Static Compression With Different Loading Magnitudes and Durations on the Intervertebral Disc An In Vivo Rat-Tail Study
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DOI：
10.1097/brs.0b013e318180e688
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发表时间：
2008-12-01
期刊：
影响因子：
3
通讯作者：
Pope, Malcolm H.
中科院分区：
文献类型：
--
作者：
Lai, Alon;Chow, Daniel H. K.;Pope, Malcolm H.
研究设计。采用活体大鼠尾模型，研究不同载荷强度和持续时间的静态压缩对椎间盘的影响。目的：探讨一段时间内不同载荷大小和持续时间的静态压缩对椎间盘的影响。背景资料摘要。椎间盘退变模型是研究椎间盘退变治疗效果的基础。静态压缩可引起椎间盘退行性改变。然而，模拟模型在静息期的结果还没有被清楚地记录下来，这可能对实验结果产生混淆效应。实验用了35只大鼠。对大鼠尾部8-9椎间盘施加不同载荷（11或17 N）和持续时间（每天1小时或连续1小时）的静态压迫2周，然后休息3周。在第4、18、39天体内定量测定椎间盘高度。测量椎间盘高度后，于第39天处死大鼠，取椎间盘进行形态学检查。结果。在11和17 N的连续静态压缩后，椎间盘高度明显下降，并在静息期继续下降。连续压缩椎间盘的形态学评价显示核大小减小，核细胞数量减少，核形状不规则，向内膨出无组织的环状胶原片。每日压迫1小时可导致椎间盘高度短暂升高，但在休息3周后恢复。每天压缩1小时后，大鼠椎间盘标本出现了良好的形态学变化，核细胞呈空泡状，核形状为卵圆形，并有组织良好的环状胶原片。大鼠尾盘连续受压后出现无恢复的椎间盘退变样改变。椎间盘高度和形态的变化与负荷施加的时间有关，可能具有临床意义。
Study Design. An in vivo rat-tail model was used to study the effects of static compression with different loading magnitudes and durations on the intervertebral disc.Objective. To investigate the effects of static compression with different loading magnitudes and durations on the intervertebral disc over a period of time.Summary of Background Data. A disc degeneration model is essential for studying therapeutic effects on degenerated disc. Static compression can induce degenerative-like changes in the intervertebral disc. However, the consequences of the simulation model over a period of resting have not been clearly documented, which may have confounding effects on the experimental outcome.Methods. Thirty-five rats were used. Static compressions with different loads (11 or 17 N) and durations (1 hour daily or continuous) were applied to the rat-tail caudal 8-9 disc for 2 weeks, and followed with 3 weeks of rest. The disc height was quantified in vivo on days 4, 18, and 39. The rats were killed and the discs were harvested for morphologic examination on day 39 after the disc height measurement. Results. Significant decrease in disc height was observed after continuous static compression for both 11 and 17 N, and continued during the resting period. The morphologic evaluation of the continuous compressed disc showed a decreased nuclear size, reduced number of nuclear cells, and irregular nuclear shape with inward bulging of disorganized annular collagen lamellas. Daily compression of 1 hour was found to induce a transient increase in disc height, but restored after the 3-week resting period. Favorable morphologic changes, including vacuolated nuclear cells and oval nuclear shape with well-organized annular collagen lamellas, were seen in the rat disc specimens with daily compression of 1 hour.Conclusion. Disc degenerative-like changes without recovery were demonstrated in the rat caudal disc after continuous compression. The changes in disc height and disc morphology were found to be dependent on the duration of load application and may have clinical implication.