可吸收性复合材料修复羊眼眶下壁缺损的实验研究

目的探讨聚乙酸-聚乙醇酸共聚物（PLGA）及其与重组人体骨形态发生蛋白2复合材料（PLGA/rhBMP-2）植入眼眶修复骨折缺损时,材料的吸收降解与眼眶骨折缺损骨化修复的关系.方法将9只山羊（18只眼）随机分为3组,每组6只眼,通过手术造成眶下壁骨折缺损.A组为对照组,其缺损不做充填修复;B组植入PLGA;C组植入PLGA/rhBMP-2薄片修复缺损.术后观察伤口愈合情况、并发症及眼眶外观变化,术后1周、3和6个月进行CT扫描、三维重建、缺损面积测量和组织学检查.结果术后所有动物伤口愈合良好,无并发症和眼球凹陷.术后6个月时A和B组CT测量的骨窗面积为51～66 mm^2和30～44mm^2,而C组的骨窗缺损基本消失.组织学检查：植入材料6个月时完全降解,A组缺损由纤维组织修复;B组周边可见骨组织,中央为纤维组织;C组缺损由骨组织取代,植片表面可见到疏松结缔组织.结论应用厚0.5 mm的PLGA/rhBMP-2薄片修复羊眼眶下壁骨质缺损,植入术后6个月材料可完全降解,被自体骨组织取代,具有较好的修复效果,对临床眼眶骨折的手术治疗有一定的指导意义.

Reconstruction of orbital floor defect with polylacticglycolide acid/recombinant human bone morphogenetic protein 2 compound implanted material in sheep

Objective To study the effect and safety of polylacticglycolide acid copolymer(PLGA) and recombinant human bone morphogenetic protein 2 (rhBMP-2) as implanted biomaterials for reconstruction orbital floor defects in sheep and find the relationship between implant materials degradation and orbital floor defects restoration. Methods Nine sheep (eighteen eyes) with orbital floor defect were divided into three groups randomly. Group A was the control without treatment. Group B was treated with PLGA and group C was received PLGA/rhBMP-2. Cosmetic appearances and complications were observed after surgery. CT scan, 3D reconstruction, defect area measurement and histological examination were performed on a week,three months and six months after operation. Results No complication was observed. The CT examinations showed that orbital floor defect in group C was almost disappeared by six months, however in group A and group B only partially orbital floor defect was repaired . Histological examinations showed that all materials were absorbed on six months. The orbit defects in group A were replaced by fiber tissue. The defect areas in group B were consisted of bone tissue in the peripheral and fiber tissue in the center. In group C the reconstructed areas were replaced by bone tissue, loose connective tissue and mucosal epithelia layers. Conclusion The thick of 0.5 mm PLGA/rhBMP-2 sheet is a good substitute material of bone graft and may be used for orbital fracture defect reconstruction in clinic in the future. (Chin J Ophthalmol,2006, 42: 535-539)