基于柠檬酸合成的新型可降解螺钉生物相容性和生物力学特性的研究

目的 探讨聚柠檬酸复合纳米羟基磷灰石（POC-Click-HA）制作的新型生物可吸收松质骨螺钉治疗比格犬股骨外髁骨折的生物相容性及生物力学特性。 方法 健康成年比格犬9只，雌雄不限，体重8~11 kg，制备双侧股骨外髁骨折（AO分型33.B1型）模型。右侧采用POC-click-HA可吸收松质骨螺钉固定，作为实验组；左侧采用聚消旋乳酸PDLLA可吸收松质骨螺钉固定，作为对照组。术后观察实验动物一般情况，分别于术后4周、8周、12周处死3只动物，取材行大体观察、Lane-Sandhu组织学评分及生物力学分析。 结果 实验动物均存活至实验完成。大体观察两组骨折无移位，均于12周愈合，POC-click-HA组螺钉可见有新生骨组织从螺钉表面向内部生长。术后3个时间点对骨折部位进行Lane-Sandhu组织学评分，两组螺钉之间无统计学差异（P>0.05）。生物力学测试，4周POC-click-HA组钉-骨界面最大载荷低于PDLLA组（P<0.05），8周和12周两者无显著差异（P>0.05）。 结论 POC-click-HA松质骨螺钉具有良好的生物相容性，生物力学性能满足固定比格犬股骨外侧髁B1型骨折。

Research on the biocompatibility and biomechanics of citrate-based biodegradable screws

weighing, 8-11 kg) were selected to prepare the models (AO classification type: B1) of bilateral lateral femoral condyle fracture. Right fracture was fixed with POC-click-HA absorbable cannulated screws as an experimental group and left fracture with Poly-DL-Lactic acid(PDLLA) screws as a control group. At 4, 8, and 12 weeks after operation, general observation was done, Lane - Sandhu histologic grading, biomechanics were taken for observing fracture healing.　Results　All aniamls survived to the end of the experiment. General observations showed that no fracture displacement occurred and fracture healed at 12 weeks in the two groups. POC - click - HA screws degraded and new bone tissue was found from samples at 12 weeks. According to the Lane - Sandhu histologic grading, , there was no statistical difference between two groups in the screws at 4, 8, and 12 weeks after operation (P>0.05). Biomechanics test showed that the maximum load at the nail-bone interface of the POC-click-HA group was lower than that of the PDLLA group at 4 weeks after operation (P<0.05). While there was no significant difference between the two groups at 8 weeks and 12 weeks (P>0.05). 　Conclusions　Citric acid polymer composite hydroxyapatite (POC-click-HA) screw has good biocompatibility and biomechanics,which can be better utilized for Beagles’ lateral femoral condyle B1 fractures.