Glazer P A, Heilmann M R, Lotz J C, Bradford D S
Department of Orthopaedic Surgery, Beth Israel-Deaconess Medical Center, Harvard University, Boston, Massachusetts, USA.
Spine (Phila Pa 1976). 1998 May 15;23(10):1142-8. doi: 10.1097/00007632-199805150-00014.
The biomechanical and histologic characteristics of posterolateral spinal fusion in a rabbit model with and without the application of low-intensity ultrasound were analyzed.
To evaluate the use of ultrasound to improve the spinal fusion rate and biomechanical characteristics of the fusion mass in a rabbit model.
This is the first study in which the benefits of ultrasound in spinal fusion have been assessed. Posterolateral intertransverse process fusion in the rabbit has a pseudarthrosis rate similar to that recorded in humans (5-40%).
Fourteen New Zealand White rabbits were randomly assigned to each of two groups to undergo spinal fusion using autologous bone with ultrasound or autologous bone without ultrasound. A specially designed plastic constraint was used to focus the ultrasound over the rabbits' lumbar spine 20 minutes per day. Animals were killed at 6 weeks for biomechanical and histologic testing.
The rate of pseudarthrosis, evaluated radiographically and manually in a blinded fashion, decreased at a statistically significant rate (from 35% to 7%) with ultrasound. Biomechanical analysis of the fusion mass showed that ultrasound resulted in statistically significant increases in stiffness (33%; P = 0.03), area under the load displacement curve (25%; P = 0.05), and load to failure of the fusion mass (24%; P = 0.04). Qualitative histologic assessment showed increased bone formation in those fusions exposed to ultrasound.
Lumbar spinal fusion is a complex biologic process. The results of the current study demonstrate the reproducibility of a rabbit fusion model and the ability of ultrasound to induce a statistically significant increase in fusion rate, stiffness, area under the load displacement curve, and load to failure of the fusion mass. These results provide a basis for continued evaluation of biologic improvement of spinal arthrodesis with the use of ultrasound.
分析在兔模型中应用和未应用低强度超声时后外侧脊柱融合的生物力学和组织学特征。
在兔模型中评估超声对提高脊柱融合率及融合块生物力学特性的作用。
这是第一项评估超声在脊柱融合中作用的研究。兔的后外侧横突间融合假关节形成率与人的记录相似（5%-40%）。
将14只新西兰白兔随机分为两组，分别采用自体骨加超声或自体骨不加超声进行脊柱融合。使用专门设计的塑料固定装置每天将超声聚焦于兔腰椎20分钟。在6周时处死动物进行生物力学和组织学检测。
通过影像学和盲法手动评估，假关节形成率在超声作用下以统计学显著速率降低（从35%降至7%）。融合块的生物力学分析表明，超声使融合块的刚度（增加33%；P = 0.03）、载荷-位移曲线下面积（增加25%；P = 0.05）以及融合块的破坏载荷（增加24%；P = 0.04）有统计学显著增加。定性组织学评估显示，接受超声的融合中骨形成增加。
腰椎脊柱融合是一个复杂的生物学过程。本研究结果证明了兔融合模型的可重复性以及超声能够使融合率、刚度、载荷-位移曲线下面积和融合块破坏载荷在统计学上显著增加。这些结果为继续评估超声在脊柱融合生物改良方面的作用提供了依据。
