椎体后凸成形术对压缩性腰椎骨折复位的体外实验评估

Ex Vivo Evaluation of Inflatable bone tampused to reduce fractures within vertebral bodies

目的研究在生理负荷下椎体后凸成形术对压缩性骨折的椎体撑开复位作用。方法从尸体获得20个骨质疏松胸腰段脊柱椎体标本,制备压缩椎体骨折的模型。每个椎体放入一种特殊的射线可以透过的负荷装置的两块压盘中间并且施加预先设定的模拟人体内生理的载荷,10个为低负荷111N,10个为高负荷组222N。扩张骨球囊并且通过X线透视测出复位术后的椎体高度。结果比较实验条件(原始的,压缩后的,撑开后的),在负荷组之间(低负荷相对高负荷)椎体高度变化没有显著的差异,然而,在这些条件下每个负荷组里椎体高度前后的变化有明显的差异。低负组和高负荷组平均撑起后高度(分别是24.1mm和24.2mm)明显大于平均压缩后高度(分别是21.4mm和22.3mm),但又明显的低于各自组原始的椎体高度(分别是26.4mm和26.2mm)。在这两组中完全恢复椎体原始高度的有20%。结论椎体后凸成形术可以恢复在模拟生理载荷下引起的压缩性椎体骨折的部分高度。

Objective To determine if fracture reduction could be achieved by the inflatable bone tamp（tamp） in vertebral bodies under simulated physiologic loads.Methods Simulated compression fractures were experimentally created in 20 osteoporotic vertebral bodies alternatingly assigned to one of two treatment（tamp inflation） groups：low axial load（111 N） or high axial load（222 N） .Each vertebral body was then placed between two platens in a special radiolucent loading fixture and subjected to the preassigned load to simulate in vivo physiologic loading.The tamps were inflated and postreduction heights were measured fluoroscopically.Results Comparing the experimental conditions（initial,postcompression,postinflation） ,there were no significant vertebral body height differences between the load groups（low load vs.high load） .However,vertebral body height differences between conditions within each load group were all significant.For the low-load and highload groups,mean postinflation heights（24.1 and 24.2mm） were significantly greater than mean postcompression heights（21.4 and 22.3 mm） but significantly less than initial vertebral body heights（26.4 and 26.2 mm） ,respectively.Initial heights were fully restored in 20% of vertebral bodies in both groups.Conclusions The inflatable bone tamp restored some of the height lost to compression fractures in vertebral bodies under simulated physiologic loads.