羟基磷灰石材料结合牵拉成骨技术修复骨缺损的实验研究

Experimental research on repairing of bone defect by using hydroxyapatite combined with distrac- tion osteogenesis technique

目的探讨羟基磷灰石（hydroxyapatite／tri．calciumphosphase，HA／TCP）材料结合牵拉成骨技术是否能减少治疗骨缺损所需的时间并促进骨的矿化过程。方法将36只健康雄性新西兰大白兔（20-24周，体重2．2-2．8kg）随机分为3组，每组12只。于左胫腓关节下方做1cm的胫骨缺损。A组：将骨缺损两端靠拢，外固定架加压固定。B组：将1cm长的HA／TCP材料填入1cm的骨缺损中，外固定架加压固定。C组：将骨缺损两端拉近至间距O．5cm，将0．5cm长的HA／TCP材料填人剩余的0．5cm骨缺损中，外固定架加压固定。除B组外，A、C组均于术后7d开始延长胫骨，A组延长10d，C组延长5d。在术后即刻、12、17、27、37d用“C”型臂X线机观察各组新生骨的矿化过程。所有动物于术后37d处死，取新生骨样：本测量骨矿物质含量（BMC）和组织矿物质含量（TMC），行胫骨扭转实验及组织病理学分析。结果C组BMC为（454．44±89．98）mg和TMC为（454．40±89．97）mg显著高于A、B两组。C组新生骨的最大扭矩、新生骨的成熟度均明显高于A、B两组，骨的矿化和重塑也较快。C组在观察期总共37d内骨愈合良好，但A、B两组在37d内并未达到骨愈合。结论在兔胫骨缺损延长模型中，与单一疗法相比，联合应用羟基磷灰石材料和牵拉成骨技术可减少治疗时间并促进骨的矿化。

Objective To investigate whether the combination of hydroxyapatite/tri-calcium phos- phase （HA/TCP） and distraction osteogenesis technique would greatly reduce the time for the treatment of bone defects and enhance bone consolidation. Methods Osteotomy was made in the left tibia of all the 36 rabbits （age 20--24 weeks, body weight 2.2-2.8 kg）, and a 1.0 cm length of the tibial shaft was removed be- low the tibiofibular junction. All rabbits were randomly divided into 3 groups, 12 per group. Group A： The 1.0 cm defect gap was immediately reduced with the tibia shortened for 1.0 cm. Group B： The 1.0 cm defect gap was immediately filled with 1.0 cm restorable porous I-IA/TCP cyhndrical block. Group C： The 1.0 cm defect gap was immediately reduced with the tibia shortened for 0.5 cm, and the remaining 0.5 cm defect gap was filled with 0.5 cm restorable porous HA/TCP cylindrical block. Then all the tibia was fixed with uni- lateral lengthener. For Group A and Group C, the lengthening started on the seventh day postoperatively, and lasted for 10 days and 5 days respectively. Group B didn＇t perform lengthening. All the rabbits wore termi- nated on the 37th days postoperatively. Serial radiographs were taken on the day of surgery, 12, 17, 27 and 37 d postoperatively. The excised bone specimens were subject to micro-CT, mechanical testing, and histo- logical examinations. Results Compared with the other two groups, the results in Group C were better in the terms of bone mineral content 454.44_±89.98 mg, tissue mineral content 454.40_±89.97 mg, maximum torque, maturity of regenerate bone, and the speed of bone consolidation and remodeling. Complete bone healing was achieved in the Group C within 37 days, but not in the Group A and B within 37 days. Conclu- sion The combination of HA/TCP and distraction osteogenesis technique can reduce the treatment time and promote bone consolidation compared with single treatment.