可降解高分子网状球囊及磷酸钙骨水泥椎体填充后的力学变化

Vertebral bodies implanted with biodegradable reticulated balloon and calcium phosphate cement:Changes in the vertebral biomechanics

背景:寻找具备生物力学性能与生物活性,椎体外渗漏率低的新型椎体填充材料已经成为研究的焦点。目的:观察植入可降解高分子网状球囊并灌注磷酸钙骨水泥椎体的生物力学性能及骨水泥渗漏率。方法:将32个猪单椎体标本随机分为4组,其中2组分别经单侧椎弓根注入2.5-3.0 mL聚甲基丙烯酸树脂骨水泥、2.5-3.0 mL磷酸钙骨水泥;其中1组首先植入可降解高分子网状球囊,然后填充2.5-3.0 mL磷酸钙骨水泥;最后1组为正常椎体。观察各组椎体的骨水泥外漏情况,经SCHENCK RSA-250电子万能试验机测试各组椎体的刚度及强度。结果与结论:聚甲基丙烯酸树脂骨水泥组椎体强度及刚度明显高于正常椎体(P<0.05),磷酸钙骨水泥组椎体强度及刚度明显低于正常椎体(P<0.05),可降解高分子网状球囊联合骨水泥组椎体强度及刚度接近正常椎体(P>0.05),可降解高分子网状球囊联合骨水泥组骨水泥渗漏率较聚甲基丙烯酸树脂骨水泥组与磷酸钙骨水泥组降低(P<0.05)。表明植入可降解高分子网状球囊联合磷酸钙骨水泥椎体的生物力学性能最接近正常椎体,骨水泥渗漏率校低。

BACKGROUND： It has become a focus to look for new vertebral body filling materials which have the biomechanicat property, biological activity and low cement leakage rate. OBJECTIVE： To investigate the biomechanical characters and cement leakage rate of the vertebral bodies implanted with biodegradable reticulated balloon and calcium phosphate. METHODS： Thirty-two vertebral bodies from pigs were randomly divided to four groups. For A group, 2.5-3.0 mL polymethacrylate cement was injected into the body through a unilateral thoracic pedicle pathway; for B group, 2.5-3.0 mL calcium phosphate cement were injected by the same protocol; for C group, the biodegradable reticulated balloons filled with 2.5-3.0 mL calcium phosphate cement were implanted; D group, including normal vertebral bodies, was designed as controls. Leakage of bone cement was observed in each group. The load-shift curves were recorded by an electronic universal testing machine .（SCHENCK RSA-250）. RESULTS AND CONCLUSION： The stiffness and strength of A group were significantlY higher than those of D group （P 〈 0.05）, and the stiffness and strength of B group were statistically lower than those of D group （P 〈 0.05）. The stiffness and strength of C group, otherwise, were similar with those of D group （P 〉 0.05）. Cement leakage rate of C group was lower than that of A or B group （P 〈 0.05）. Vertebral bodies implanted with biodegradablereticulated balloons may lead to similar biomechanical characters as the normal vertebral bodies and reduce the cement leakage rate.