镁基植入体植入兔股骨后周围骨微结构变化趋势

Bone Microstructural Changes Around the Magnesium Based-Implant after Implantation in Rabbit Femur

目的研究镁基植入体植入兔股骨不同时间点周围骨微结构参数的变化规律。方法将直径2 mm、长7 mm有螺纹及无螺纹的高纯镁(99.99 wt.%)钉植入兔股骨髁,对照组为钻孔组及健康组。在术后8、12、16周进行Micro-CT扫描和分析,得到各组微结构参数,包括:骨质密度(BMD)、骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁数量(Tb.N)、骨小梁分离度(Tb.Sp)。结果 8周时无螺纹镁钉组BMD、BV/TV显著高于健康组,Tb.N显著高于钻孔组与健康组,Tb.Sp显著低于健康组;12周时有螺纹镁钉组BMD、BV/TV、Tb.N显著高于钻孔组与健康组,Tb.Th显著高于健康者,Tb.Sp显著低于钻孔组与健康组;16周时无螺纹镁钉组的BMD、BV/TV、Tb.N显著高于钻孔组与健康组,Tb.Sp显著低于钻孔组与健康组。结论镁基植入体促使周围骨组织的BMD、BV/TV、Tb.Th、Tb.N更高,Tb.Sp更低,说明其骨整合与骨生长状况良好,镁基植入体能有效促进骨再生。研究结果为镁基植入体的骨科临床应用提供理论依据。

Objective To study the change patterns of bone microstructural parameters around the magnesium based-implants after implantation in rabbit femur at different implantation time points. Methods The threaded and non-threaded high-purity magnesium(HP Mg, 99.99 wt.%) screws, with a 2 mm diameter and a 7 mm length, were implanted into the femoral condyle of the rabbits. The control group was the drilled and healthy group. Micro-CT scanning and analysis were performed at 8th, 12th and 16th week after operation. The obtained microstructural parameters included bone mineral density(BMD), bone volume fraction(BV/TV), trabecular thickness(Tb.Th), trabecular number(Tb.N), trabecular separation(Tb.Sp). Results At 8th week, BMD and BV/TV in non-threaded magnesium screw group were significantly higher than those in healthy group, Tb.N was significantly higher than that in drilled and healthy group, and Tb.Sp was significantly lower than that in healthy group. At 12th week, BMD, BV/TV and Tb.N in threaded magnesium screw group were significantly higher than those in drilled and healthy group, Tb.Th was significantly higher than that in healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. At 16th week, BMD, BV/TV and Tb.N in non-threaded magnesium screw group were significantly higher than those in drilled and healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. Conclusions The magnesium based-implant promoted higher BMD, BV/TV, Tb.Th, Tb.N and lower Tb.Sp of surrounding implant, indicating that osseointegration and bone growth were in good condition. Magnesium based-implant could effectively promote the regeneration of bone. The results provide a theoretical basis for the orthopedic application of magnesium based-implants in clinic.