可吸收珊瑚羟基磷灰石与天然珊瑚修复骨缺损的组织学及影像学分析

Histologic and Roentgenographic study of Bone DefectRepaired by Absorbable Coralline Hydroxyapatite

目的采用组织学及影像方法观察可吸收珊瑚羟基磷灰石与天然珊瑚修复骨缺损的生物学特性。方法采集海南滨珊瑚,在一定的条件下珊瑚碳酸钙在"水热交换反应"转化成含羟基磷灰石80%的可吸收珊瑚人工骨(CHAP)。CHAP送国家材料实验室进行物理及化学检测。用40只新西兰大白兔,手术切除兔桡骨中段1.5cm,将长1.5cm、直径0.4cm的可吸收珊瑚羟基磷灰石植入骨缺损区,对照组植入天然珊瑚(NC)。术后分批处死动物,拍X光照片,行组织学切片,对该人工骨的生物相容性和成骨效应进行了X线及组织学观察。结果珊瑚磨片片测得珊瑚孔道直径平均200m,孔隙率为51%。X光照片显示2周CHAP组织结构完整,NC组有少许吸收,4周时CHAP有大量外骨痂形成,NC组吸收明显,8周CHAP组与宿主骨完全愈合,NC组的移植材料大部吸收。术后2周可CHAP组有许多成纤维细胞和毛细血管长入珊瑚骨的微孔内,并有少量新生骨自接触部向珊瑚骨内爬行;天然珊瑚组孔道内为含新生骨的纤维结缔组织,内有炎性细胞浸润;4周时CHAP组有大量新生骨内含大量的毛细血管、成骨细胞及骨基质由周边深入珊瑚骨的中部,移植的人工骨面积无减少。NC组周边有新生骨形成,移植物面积减少(<0.001);8周时CHAP组有大量成熟板层骨分布整个移植物的孔道内,部分骨组织内含有骨髓组织,人工骨有少量吸收。NC组在骨缺损未修复时移植物已大部吸收。结论通过对可吸收珊瑚羟基磷灰石材料与天然珊瑚材料体内植入的组织学及影像学分析比较,证实可吸收珊瑚羟基磷灰石是一种新型的可吸收骨组织移植替代材料,其理想的体内吸收速率与骨缺损修复的再生速率相吻合,作为骨缺损修复所必需的骨诱导活性是其独特的多孔结构所决定的,并具有良好的生物相容性和成骨潜能.

Objective To explore the biologic features of a new bone graft substitute material absorbable coralline hy- droxyapatite （CHAP） in the repair of radial bone defect by means of histology and roentgenography. Method To convert Hainan Sanya bay natural coral into absorbable coralline hydoxyapatite by “hydrothermal exchange” process. 40 New Zealand white rabbit were used. CHAP group were inserted a 15mm long 4mm in diameter of coralline hydroxyapatite into one side of the rabbit radius bone defect which was resected by operation, Nc group were inserted a nature coral in the same size of CHAP into the other side of radius bone defect, After 2, 4, 8 weeks the rabbit were killed and X-ray, his- tologic section were taken. 46 cases of clinic bone defect repairment were done at the femur, tibia, radius, vertebral body. Result X-ray show CHAP group remained its original shape at the time of two weeks, Nc group show a little absorbing of the material. At 4 week, a large amount of bone callous were formed around the material in CHAP group, but apparently absorbed in Nc group. At 8 weeks, graft materials were healed with the host bone in CHAP group, but completely absorbed in Nc group. Histologic slides show the pore size of the coralline hydroxyapatite is 200um in diameter and pore rate is 51%. Two weeks after operation, the pores of the CHAP were filled with fibrous cell and capillariers, new bone growth toward the center of the material, Nc were filled with fibrous tissue with a few inflammation cells. At 4 weeks, a large am- ount of new bone with capillariers, osteogenetic cell and bone matrix growth into the center part of the CHAP and the sur- face area remained original, however, new bone only around the surrounding part of the Nc and the Nc surface area reduce to small area （P〈 0.0001 ）. At 8 weeks, mature bone was filled in the pores of the CHAP, while the Nc material almost com-pletely absorbed. Clinic result shows all wounds were healed with no swelling. X-ray shows all the CHAPs were healed with host bone in 2 - 4 months, Conclusion Two groups comparison experiment test shows that CHAP is chemical sta- ble, good histologic compatibility, osteoconductive, so it can repair the long segment bone defect. Clinic result show CHAP can repair long segment bone defect of patient. Therefore, CHAP is one of the idea bone graft substitute material.