Benoit A, Mustafy T, Londono I, Grimard G, Aubin C-E, Villemure I
Polytechnique Montreal, Department of Mechanical Engineering, Downtown station, PO Box 6079, Montreal, QC H3C 3A7, Canada.
J Musculoskelet Neuronal Interact. 2016 Sep 7;16(3):211-20.
Fusionless devices are currently designed to treat spinal deformities such as scoliosis by the application of a controlled mechanical loading. Growth modulation by dynamic compression was shown to preserve soft tissues. The objective of this in vivo study was to characterize the effect of static vs. dynamic loading on the bone formed during growth modulation. Controlled compression was applied during 15 days on the 7(th) caudal vertebra (Cd7) of rats during growth spurt. The load was sustained in the "static" group and sinusoidally oscillating in the "dynamic" group. The effect of surgery and of the device was investigated using control and sham (operated on but no load applied) groups. A high resolution CT-scan of Cd7 was acquired at days 2, 8 and 15 of compression. Growth rates, histomorphometric parameters and mineral density of the newly formed bone were quantified and compared. Static and dynamic loadings significantly reduced the growth rate by 20% compared to the sham group. Dynamic loading preserved newly formed bone histomorphometry and mineral density whereas static loading induced thicker (+31%) and more mineralized (+12%) trabeculae. A significant sham effect was observed. Growth modulation by dynamic compression constitutes a promising way to develop new treatment for skeletal deformities.
目前，无融合器械被设计用于通过施加可控的机械负荷来治疗脊柱畸形，如脊柱侧弯。动态压缩调节生长被证明可保留软组织。本体内研究的目的是确定静态负荷与动态负荷对生长调节过程中形成的骨骼的影响。在大鼠生长突增期间，对第7尾椎（Cd7）进行为期15天的可控压缩。“静态”组的负荷保持不变，“动态”组的负荷呈正弦振荡。使用对照组和假手术组（进行手术但未施加负荷）研究手术和器械的效果。在压缩的第2天、第8天和第15天对Cd7进行高分辨率CT扫描。对新形成骨骼的生长速率、组织形态计量学参数和矿物质密度进行量化并比较。与假手术组相比，静态和动态负荷均使生长速率显著降低了20%。动态负荷可保留新形成骨骼的组织形态计量学和矿物质密度，而静态负荷则导致小梁增厚（增加31%）且矿化程度更高（增加12%）。观察到显著的假手术效应。动态压缩调节生长是开发骨骼畸形新治疗方法的一种有前景的途径。
