两种新型骨水泥的组织学和生物力学研究

HISTOLOGICAL AND BIOMECHANICAL STUDIES OF TWO BONE COLONIZABLE CEMENTS IN RABBITS

我们研制了两种可被骨长入的骨水泥：一种是部分可吸收的骨水泥（ＰＲＣ），以双酚α-甲基丙烯酸甘油酯（Bis-GMA）为基质，混合硅铝陶瓷和可吸收性聚合体颗粒调制成；另一种是磷酸钙骨水泥（ＣＰＣ），由磷酸三钙、一水磷酸二氢钙、二水磷酸二钙和黄原胶组成。将这两种骨水泥分别植入家兔股骨和胫骨髁的骨缺损中，植入后2、4、12和24周取材，进行组织学观察和生物力学测试。结果发现，CPC组有递增的骨整合，伴有生物降解及巨噬细胞出现，力学测试显示抗压强度在4周之前一直降低，4周后才轻微升高，弹性模量随时间普遍降低。到第4周时，组织学观察还发现新生骨与CPC边缘直接接触。整个观察过程中未发现炎症反应。PRC组，骨整合及生物降解都很轻微，但在各个观察阶段，其抗压强度比松质骨和CPC组高（p＜0.05），在4周之前，它的弹性模量高于松质骨和CPC组，4周后低于松质骨。（Bone 25：41S--45S；1999）。

we have developed two colonizable bone cements :the first is a partially resorbable bisphenol-a-glycidyl methacrylate (Bis-GMA)-based cement(PRC) and the second is a calcium phosphate cement (CPC).PRC is composed of aluminous silanized ceramic and particles of a bioresorbable polymer embedded in a matrix of Bis-GMA.CPC consisted of tricalcium phosphate, monocalcium phosphate monohydrate ,dicalcium phosphate dihydtrat ,and xanthane.Both cements were implanted into cavities drilled in rabbit femoral and tibital condyles .After 2,4 ,12,and 24 weeks of implantation ,histological observations and biomechanical tests were performed .With CPC, a progressive osteointegration with a concomitant biodegradation in the presence of macrophages were observed,The mechanical study revealed a decrease of the compressive strength unitil the 4th week,followed by a concomitant biodegradation in the elastic modulus with time .Moreover.by week 4, the histological study showed that the new bone was in direct contact with CPC margins .No inflammation was observed during the observation period. Strength was higher than that of cancellous bone and CPC(P<0.05) ar all observation periods.Its elastic modulus was greater than that of cancellous bone and CPC until the 4th week ,then fell under the values of the cancellous bone,(Bone 25:41s;1999)