树脂-羟磷灰石复合材料应用于经皮椎体成形术的实验研究

目的探讨应用树脂-羟磷灰石（EH）复合材料行经皮椎体成形术的适当配比比例及显影剂的使用。方法按液粉比8：9、8：8、8：7配制成Ⅰ、Ⅱ、Ⅲ组,分别在粉剂中加入20％硫酸钡的配制成Ⅳ、Ⅴ、Ⅵ组;测量混合时的物料状态和发热温度;Ⅰ～Ⅴ组制成直径5mm,高20mm的圆柱体,行X线摄片,观察显影性;Ⅰ、Ⅱ、Ⅳ、Ⅴ组圆柱体进行抗压强度测试。将骨质疏松椎体T8～L5做成压缩骨折模型,配比为8：8的对照组和加入20％硫酸钡的实验组进行配对实验,在37℃水浴中,注入骨水泥,测量椎体中心的温度和椎管后壁的温度（PT）,并记录骨水泥注入量;行X线摄片,观察显影性;在力学材料机上测量两组椎体的强度及刚度,对比EH复合骨水泥加入造影剂前后恢复椎体强度和刚度的能力。结果加入20％硫酸钡的EH材料粥样期适当延长,约60s,温度降低,显影性良好,容易注射,机械强度较高。对照组和实验组均很好地恢复了椎体的强度和刚度,实验组显影性良好,PT不超过50℃。结论加入20％硫酸钡的液粉比为8：8的EH材料是用于治疗疼痛性椎体压缩骨折良好、有效的填充材料。

Percutaneous vertebroplasty with EH composite material: an experiment study

OBJECTIVE: To investigate the appropriate ratio of liquid/powder and use of radiopaque agent in EH composite material for percutaneous vertebroplasty (PVP). METHODS: (1) EH composite material was divided into 6 groups. The material without contrast with the liquid/powder ratios 8:9, 8:8, and 8:7 was classifieds as groups I, II, and III; and the EH composite material with the liquid/powder ratios 8:9, 8:8, and 8:7 and with the addition of 20% barium sulfate by weight was classified as the groups IV, V, and VI. The curing temperature was measured. The bone cement of different groups was made into cylinders to be X-rayed to observe the opacity. Universal tester was used to examine the strength and stiffness. (2) The vertebrae (T8 approximately L5) were isolated from the cadaver of an elder female patient with osteoporosis. Universal tester was used to examine the strength and stiffness of the vertebral bodies (VBs). Osteoporotic vertebral compression fracture (OVCF) model was made. PVP procedure was mimicked by puncturing through the bilateral pedicle of vertebral arch into the anterior 1/3 of the vertebral bodies and the EH composite materials of the groups II and V were injected into the VBs Then the temperatures of the geometric center (CT) and spinal canal posterior wall (PT) of the VBs were measured in a water bath with the temperature of 37 degrees C. Twenty-four hours later the vertebrae underwent X-ray examination to observe the opacity and underwent examination of strength and stiffness with universal tester. RESULTS: (1) The sticking periods (?) of the groups IV, V, and VI were significantly longer than those of the corresponding groups I, II, and III respectively by about 60 s, and the highest temperature of the groups IV, V, and VI were significantly lower than those of the corresponding groups I, II, and III respectively. Addition1 of barium sulfate increased the opacity of the bone cement, but did nor significantly influence the strength of the bone cement. The properties of the group V was the best. (2) The bone cement was easy to be injected into the VBs. The peak PT was not beyond 50 degrees C. After the injection of the bone cement of the groups II, the strength and stiffness of the VB were (1501.6 +/- 5.0) N/mm and (285.6 +/-) N/mm, both significantly higher than those before the injection (547.5 +/- 3.1) N/mm and (104.1 +/- 1.3) N/mm]; and after the injection of the bone cement of the groups V, the strength and stiffness of the VB were (1355.0 +/- 4.5) N/mm and (257.7 +/- 1.9), both significantly higher than those before the injection (543.8 +/- 2.7) N/mm and (103.4 +/- 1.1) N/mm]. The opacity of the VBs injected with the bone cement of the group V was better than those injected with the bone cement of the group II. CONCLUSION: The EH (8/8) with 20% barium sulfate is a proper and effective filling material for the treatment of OVCF.