摘要
目的 明确应力松弛接骨板体内应力遮挡率变化及其对骨折愈合力学性能的影响。方法 将兔两侧胫骨干横形截骨后 ,分别以应力松弛接骨板 (Stress—relaxationplateSRP)和传统坚硬接骨板 (RigidplateRP)固定 ,观察其应力遮挡率变化及愈合骨力学性能变化。结果 两组固定初期 ,应力遮挡率均在 70 %左右 ,此后 ,SRP组随着固定时间延长 ,应力遮挡率逐渐下降 ,8周后 ,明显低于RP组 ;与此相应 ,愈合骨力学性能也逐渐增加 ,至 48周达到正常骨的 93 6 3%。RP组 ,2 4周后愈合骨力学强度逐渐下降 ,48周时 ,最大三点弯曲强度仅为正常 5 7 95 %。结论 应力松弛接骨板体内应力遮挡率的下降与固定时间具有良好的相关性 ;应力遮挡作用的减弱 ,促进了愈合骨力学性能的恢复。
Objective To study the changing rule of stress shielding rate of stress-relaxation plate SRP in Vivo,and its effects on the mechanical property of fracture healing Methods The bilateral tibia of New Zealand rabbit were osteotomized and fixed with Stress—relaxation plate (SRP) and Rigid plate (RP)respectively The stress shielding rate assay and ultimate bending strength test (UBS) were used in this experiment from 2 to 48 weeks postoperatively Results The stress shielding rate of either fixing with SRP or RP was about 70% at the beginning of fixation,but the stress-shielding rate of SRP decreased gradually along with the prolongation of fixing time By 8 to 48 weeks after fixation,it was significantly lower than that of RP(P<0 05～0 01),and stabilized at about 27% during 36～48weeks after fixation Meanwhile,The mechanical strength of united bone restored gradually,the UBS was 93 63 percent of the normal rabbit’s tibia by 48 weeks On the contrary, The mechanical property of synthetic bone reduced gradually along with the prolongation of fixation time,The UBS was only 57 95 percent of the normal rabbit’s tibia by 48 weeks Conclusions The SRP can gradually lower down its stress shielding rate in Vivo,so as to enhance the recovery of mechanical property of synthetic bone
出处
《骨与关节损伤杂志》
2000年第1期30-32,共3页
The Journal of Bone and Joint Injury
基金
国家自然科学基金
关键词
接骨板
骨折愈合
应力遮挡
生物力学
Bone plate
Fracture healing
Stress shielding
Biomechanics
