郝毅 杨文勋 赵大正 郝毅(浙江医院骨科 杭州市 310013)；杨文勋(新疆钢铁集团公司总医院骨科)；赵大正(浙江医院骨科 杭州市 310013) 骨与关节损伤杂志 2000 0 15 1


    关键词：拇指掌骨基底；骨折；牵引；固定架 期刊 gygjsszz 0 28??29 论著 fur -->


    

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-relaxationplate SRP)和传统坚硬接骨板(Rigid plate RP)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93.63%。RP组,24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57.95%。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。

A Biomechanical Study ofthe Effects of Stress-relaxationBone Plate on Fracture Healing

Zhang Xianlong,Dai Kerong,Tang Tingting

    (Department of Orthopaedics,The Ninth People's Hospital,Shanghai the Second Medical University,Shanghai,200011)

Abstract：Objective To study the changing rule of stress shielding rate ofstress-relaxation plate SRP in Vivo,and its effects on the mechanical property of fracture healing.Methods The bilateral tibia of NewZealand 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 ofeither fixing with SRP or RP was about 70% at the beginning of fixation,but the stress-shielding rate ofSRP decreased gradually along with the prolongation of fixing time.By 8 to 48 weeks afterfixation,it wassignificantly 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 thenormal rabbit's tibiaby 48 weeks.On the contrary,The mechanical property of synthetic bone reduced gradually alongwith 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 downits stress shielding rate in Vivo,so as to enhance the recovery of mechanical property of syntheticbone.

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