目的：观察可注射性羟基磷灰石/壳聚糖复合材料对兔桡骨骨缺损修复效果。方法：18只新西兰白兔双侧桡骨中段建立长度为10mm节段性缺损，将可注射性纳米羟基磷灰石/壳聚糖复合材料植入一侧骨缺损作为实验组，另一侧植入单纯羟基磷灰石材料作为对照组，于第4、8、12周末,分别行大体、X线检查、组织学、电镜检测，观察该材料对骨缺损的修复效果。结果：①大体观察、X线检查提示：实验组骨痂生长良好，骨缺损完全修复，对照组骨缺损部分修复，部分骨皮质不连续。②组织形态学: 术后12周，实验组新生骨皮质连接完整,髓腔完全再通；对照组少量新生骨形成，部分纤维组织填充③电镜检查:12周实验组材料基本降解，被新生骨组织替代。结论：可注射性纳米羟基磷灰石/壳聚糖复合材料骨缺损修复能力较单纯羟基磷灰石好，具有确实的骨缺损修复能力。

        Objective: To explore repair effects of  injectable nano-hydroxyapatite/ chitosan（nHA/CS） composite on radius bone defect. Methods: Bone defect with the length of 10 mm were created on the middle of each radius of 18 New Zealand white rabbits. the defects was filled with the nHA/CS composite as treatment group, while the others were filled with hydroxyapatite（HA） as control. The ability of repairing bone defect was evaluated by gross observation, X-ray, histopathological and SEM 4, 8, 12 weeks after operation. Results: ① The gross and X-ray showed that, in treatment group, the callus grew well and bone defect was repaired completely, oppositely, in control group, bone defect was repaired partly, with some nonunion. ② Histomorphology showed that, the new formed bone in treatment group was confirmed integral and the medullary cavity recanalized after 12 weeks, however, a little of  new  bone formed in the control group, accompanied with connective tissues growing into the defects. ③ Under the SEM, materials was replaced by newly formed bone after 12 weeks in treatment group. Conclusions: The nHA/CS has better ability of bone repairing than that of the HA.