Department of Orthopaedic Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
Biomech Model Mechanobiol. 2010 Oct;9(5):533-8. doi: 10.1007/s10237-010-0193-y. Epub 2010 Feb 11.
This study involves a biomechanical evaluation of a prospective injectable treatment for degenerative discs. The high osmolarity of the non-degenerated nucleus pulposus attracts water contributing to the hydrostatic behavior of the tissue. This intradiscal pressure is known to drop as fluid is exuded from the matrix due to compressive loading. The objective of this study was to compare the changes in intradiscal pressure in control and genipin cross-linked intervertebral discs. Thirty bovine lumbar motion segments were randomly divided into a phosphate-buffered saline control group and a 0.33% genipin group and soaked at room temperature for 2 days. A needle pressure sensor was held in the center of the disc while short-term and static creep compressive loads were applied. The control group demonstrated a 25% higher average intradiscal pressure compared to genipin-treated discs under 750 N compressive load (p=0.029). Depressurization during static compressive creep was 56% higher in the control than in the genipin group (p=0.014). These results suggest cross-linking induced changes in the poroelastic properties of the involved tissues affected the mechanics of compressive load support in the disc with lower levels of nucleus pressure, a corresponding decrease in the elastic expansion of the annulus, and an increased axial compressive loading of the inner and outer annulus tissues. It is possible that concurrent changes in hydraulic permeability and proteoglycan retention known to be associated with genipin cross-linking were also contributors to poroelastic changes. Reduction of peak pressures and moderation of pressure fluctuations could be beneficial relative to discogenic pain.
本研究对一种潜在的退行性椎间盘注射治疗进行了生物力学评估。未退变的髓核的高渗透压吸引水分，从而导致组织的静水行为。已知由于压缩载荷，基质中的流体渗出会导致椎间盘内压力下降。本研究的目的是比较对照组和京尼平交联椎间盘内压力的变化。将 30 个牛腰椎运动节段随机分为磷酸盐缓冲盐水对照组和 0.33%京尼平组，并在室温下浸泡 2 天。当施加短期和静态蠕变压缩载荷时，将针压传感器保持在椎间盘的中心。在 750N 压缩载荷下，对照组的平均椎间盘内压力比京尼平处理组高 25%（p=0.029）。在静态压缩蠕变过程中，对照组的减压率比京尼平组高 56%（p=0.014）。这些结果表明，交联引起的相关组织的多孔弹性特性变化影响了椎间盘在较低核压力下的压缩载荷支撑力学，相应地降低了环的弹性扩张，并增加了内外环组织的轴向压缩载荷。可能与京尼平交联相关的液压渗透性和蛋白聚糖保留的同时变化也是多孔弹性变化的原因。与椎间盘源性疼痛相比，降低峰值压力和缓和压力波动可能是有益的。
