Castro W H, Jerosch J, Brinckmann P
Klinik und Poliklinik für Allgemeine Orthopädie, Westfälischen Wilhelms-Universität Münster.
Z Orthop Ihre Grenzgeb. 1992 Nov-Dec;130(6):472-8. doi: 10.1055/s-2008-1039655.
For a biomechanical study 8 specimens of the lumbar spine (L1-S1) were scanned with MRI. After that 21 motion segments were prepared for the experiments. The paraspinal musculature as well as the posterior elements were removed. From each disc 1,0 g, 2,0 g, and 3,0 g of nuclear material were consecutively removed under an axial load of 500 N. At the beginning of every standardized experiment of a motion segment, as well as after the excision of every gram of nuclear material, intradiscal pressure, the height of the disc and the contour of the disc were determined with an axial load on the motion segment of 1000 N. The change in radial bulging of the disc was measured using the computer-assisted recordings of each disc contour. All the data were statistically analyzed using the Friedman-test. The nuclear material removed from the discs ('in-vitro nuclear material') was placed in isotonic saline over 45 minutes and again weighted ('wet weight'). Af that the nuclear material was freeze-dried ('dry weight'). The results of this study showed that after the excision of every gram of nuclear material the height of the disc decreased in average 0,77 mm. Also intradiscal pressure reduces significantly: from the initial stage, on average, 9, 19 bar to the endstage (= after the removal of 3,0 g), on average, 2, 58 bar. Radial bulge increases with every gram removed, on average 0,23 mm. The weight of the wet nuclear material is 2,6 times as much as that of the in-vitro nuclear material and 11 times as much as that of the freeze-dried material.
为进行一项生物力学研究，对8个腰椎（L1 - S1）标本进行了MRI扫描。之后，准备了21个运动节段用于实验。去除了椎旁肌肉组织以及后部结构。在500 N的轴向载荷下，从每个椎间盘依次去除1.0 g、2.0 g和3.0 g的核物质。在每个运动节段的标准化实验开始时，以及每切除1克核物质后，在1000 N的轴向载荷下测定椎间盘内压力、椎间盘高度和椎间盘轮廓。使用每个椎间盘轮廓的计算机辅助记录来测量椎间盘径向膨出的变化。所有数据均采用Friedman检验进行统计分析。从椎间盘中取出的核物质（“体外核物质”）在等渗盐水中放置45分钟后再次称重（“湿重”）。之后将核物质冷冻干燥（“干重”）。本研究结果表明，每切除1克核物质后，椎间盘高度平均下降0.77 mm。椎间盘内压力也显著降低：从初始阶段的平均9.19 bar降至末期（即切除3.0 g后）的平均2.58 bar。每切除1克，径向膨出平均增加0.23 mm。湿核物质的重量是体外核物质的2.6倍，是冷冻干燥物质的11倍。
