聚-DL-乳酸膜引导兔桡骨缺损再生的实验研究

本实验旨在观察可降解聚 - DL-乳酸膜引导兔桡骨缺损再生的现象 ,并探讨其作用和机制。取 4 0只成年新西兰大白兔建立双侧桡骨缺损模型。左侧为实验侧 ,以聚 - DL-乳酸膜卷成管状桥接骨缺损 ;右侧为对照侧 ,桡骨缺损不做处理。术后 2、4、8、12周分别处死动物 ,行大体观察、X线摄片、组织学观察和骨生物力学检测。实验侧术后 2周 ,可见隔膜管两端已为软组织覆盖 ,膜管外两端可见多量新生骨痂形成 ,膜管内骨断端间充满与膜管形状相适应的血肿和纤维骨痂。术后 12周膜管颜色明显变白 ,仍然保持原有外形无塌陷 ,膜管外骨痂已基本消失 ,膜管内骨缺损均已骨性愈合。对照侧术后 2周骨缺损区被大量的结缔组织充填 ,12周时无 1例愈合 ,骨断端均已封闭而形成典型的骨不连。对照侧均不能进行力学测试 ,实验侧 12周组新生骨的生物力学指标明显优于 8周组 (P<0 .0 5 )。因此 ,聚 - DL-乳酸膜能够成功引导骨再生 ,可以用于临床治疗骨缺损和骨不连。

Experimental Study of Poly-DL-lactic Acid Membrane Guided Bone Regeneration in Rabbit Radii Bone Defects

This study was conducted to observe bone regeneration guided by poly-DL-latic acid (PDLLA )membrane in rabbit radii bone defects and to explore the mechanism of the membrane guided bone regeneration(MGBR). The animal models of bony and periosteous defects were established in both radii of 40 adult New Zealand white rabbits.The left defect as the experimental side was bridged with PDLLA membrane tube, the right side as the controlled side was untreated. The specimens were collected at 2, 4, 8 and 12 weeks postoperatively. General observation, X-ray, histological observation and biomechanical examination were applied to the repair of the models of MGBR in both groups. Two weeks after operation, with much new bony callus formed outside the tube at both fragments, the membrane tube covered with connective tissues was filled with haematoma and fibrous callus. Twelve weeks after operation, the PDLLA membrane became white and its tube shape was still maintained. However, new bone callus outside the tube almost completely disappeared, and inside the tubes all radii bone defects were successfully repaired with bony union. On the controlled sides, bone defects were filled with connective tissues 2 weeks postoperatively. And 12 weeks after operation, the typical nonunion that had been formed after bone marrow canals were sealed with cortical bone. On the experimental side, the strength of the newly formed bone at the 12th week was higher than that at the 8th week(P<0.05),whereas the biomechanical examination could not be done on the controlled side. Therefore, these findings suggested that the bone regeneration could be successfully guided by PDLLA membrane ,and this MGBR technique might be generally used in the treatment of bone defects and nonunion.