含rhBMP-2活性生物骨修复山羊胫骨缺损的实验研究

Antigen- free bovine cancellous bone combined with rhB MP- 2 for repairing of tibia defects: an animal experiment

[目的]研究含rh BMP-2生物活性骨修复山羊胫骨缺损后的生物学性能和新成骨特点。评价其局部成骨活性及修复骨缺损的能力,为临床骨缺损的治疗提供理论和实验依据。[方法]24只健康成年山羊,雌雄不限,体重20~25 kg,随机分为4组,每组6只,于双侧胫骨内侧正中,距平台下约20mm,制作成直径为10mm的圆形胫骨骨缺损模型,分组植入材料,A组：含rh BMP-2活性生物骨;B组：自体髂骨;C组：硫酸钙;D组：空白对照组。分别于术后4、8、12周时进行影像学及组织学检查以观察和评价骨缺损修复情况。[结果]影像学显示：术后4周可见含rh BMP-2活性生物骨开始降解吸收,骨缺损区有新生骨形成;8周可见缺损区骨痂性愈合;12周可见骨愈合,髓腔再通,皮质骨增厚。组织学显示：4周时植骨区出现大量骨小梁,材料开始降解;8周可见骨小梁融合成片,材料大部分降解;12周时骨缺损基本修复,可见板层骨,骨髓腔再通,材料被完全降解、吸收。[结论]含rh BMP-2活性生物骨具有较强的诱导成骨活性和修复骨缺损作用,具有良好的临床应用前景。

[Objective]To evaluate the biological properties,characteristics of degradation and osteogenetic activity of antigen- free bovine cancellous bone composite with rhB MP- 2in goat tibial defect model,thus to establish a theoretically therapeutic strategy for repearing bone defects in clinical practice. [Method]Twenty- four healthy adult goats of gender unlimited,weighted 20- 25 kg and housed at Animal Center of Sichuan University were chosen to establish goat tibial bone defects,which was a cylinder of 10 mm in diameter in the middle tibial shaft of each goat. And then the models were randomly divided into four groups,with six goats in each group. Repairs were performed with different implants and divided into group A,with antigen- free bovine cancellous bone / rhB MP- 2,group B,with calcium sulfate（ CS）,group C,with autogenous bone and group D,the blank group. Animals were evaluateded with radiological and histological methods at 4,8 and 12 weeks after surgery. [Result]Radiograpy showed in group A,at 4 weeks after surgery,some materials degraded,there was still some material existing,bone defect edge were blur,and some newly bone formed. At 8weeks,the materials almost degraded completely,and the amount of newly formed bone increased. Newly- formed bone and complete synostosis were observed at the 12 th week. Histological analysis showed that abundant trabecular bone and new bone islands had been found in the defects 4 weeks after the operation and remodeling of new bone and resorption of the grafts implanted had been observed at the 8th week. Complete healing was detected at the 12 th week postoperatively with the establishment of normal diaphysial structure and no remnant of the graft. [Conclusion]The composites of antigen- free bovine cancellous bone with rhB MP- 2 has a very strong osteoinductive activity and capacity to promote repair of bone defects,and can be widely used in the clinical application.