微管结构仿生人工骨对犬腔隙性松质骨缺损的修复

Repair of cancellous bone defects using bionic microstructure artificial bone in dogs

目的建立一种新型松质骨缺损动物模型,同时评价应用纤维增强微管结构仿生人工骨修复该骨缺损的性能。方法成年犬双侧股骨下段分别制备2处直径10mm、深20mm腔隙性松质骨缺损,以正交结构(A)组、同心结构(B)组仿生人工骨修复,设立磷酸钙骨水泥(calcium phosphate cement,CPC)(C)组、空白(D)组为对照,术后6、12、24周进行影像学、组织学、形态计量学观察骨缺损修复情况。结果未经治疗的骨缺损不能自行愈合;人工骨修复组6周新生骨开始长人,6、12、24周时A、B、C组的成骨面积比(%)分别为(4.09±0.96)、(6.78±1.27)、(3.10±0.83),(8.98±2.45)、(15.38±2.33)、(4.25±1.03),(19.86±4.57)、(38.25±6.79)、(4.97±0.90);相应各组CPC残留面积比(%)为83.19±3.69、81.93±3.80、86.87±4.48,68.14±5.39、34.59±5.50、75.83±4.51,38.55±4.78、22.20±3.46、62.89±4.31;各组新生骨面积比(%)B>A>C(P<0.01),CPC残留面积比(%)C>A>B(P<0.01)。结论该骨缺损模型稳定、可靠;微管结构仿生人工骨在促进成骨、加快CPC降解速度上优于不具有微管结构的人工骨,同心结构具有最佳成骨和促CPC降解作用。

Objective To design a new reliable animal model of cancellous bone defect and assess the positive influence of fiber-reinforced composite artificial bone with bionic structure on osteogeneses. Methods Seventy-two cancellous bone defects （ 10 mm in diameter and 20 mm in length） were established in inferior segments of bilateral femurs of 18 full-grown dogs and were randomly divided into 3 groups. The artificial bone cylinders with perpendicular structure （ group A）, concentric structure （ group B） and composite calcium phosphate cement （CPC） （group C） were randomly implanted into the defects and the dogs without implantation served as group D. Osteogenesis of the grafts was evaluated by the means of X-ray, histology and histomorphometry at the end of 6th, 12th and 24th week. Results The defects without implantation couldn＇ t heal spontaneously throughout 24 weeks. By the 6th week, osteogenesis began from the peripheral area. Histomorphometrical measurements were performed for the whole defect area at the end of 6th, 12th and 24th week. The bone penetration ratio in groups A, B and C was in the following decreased order ： groups B, A and C, and the difference between groups B and A, as well as between groups A and C was significant （P 〈 0.00）. The fraction of CPC remnant was in the following decreased order： groups C, A and B （ P 〈 0.01 ）. Conclusion Such a new animal model can served as a reliable model of cancellous bone defect. The novel artificial bone grafts with bionic microstructures can facilitate new bone ingrowth, biomaterials regenenration and enhance the defect healing in big animal models. The concentric fiber microstructure is more efficient than the perpendicular structure.