摘要
３０具新鲜股骨标本做成ＥｖａｎｓⅣ型转子间骨折后随机分为Ｇａｍｍａ钉、长柄Ｇａｍｍａ钉、ＡＯ角钢板、Ｒｉｃｈａｒｄｓ钉固定和正常对照共５组，实验模型每组６具标本，模拟单足站立相，进行２００Ｎ～１６００Ｎ加载，对位移和骨折远端的电应变进行测量。结果发现正常标本置入各种内固定后，股骨应变均有变化；模拟不稳定骨折后，小转子的应变以Ｒｉｃｈａｒｄｓ钉最大，其它三组均明显减小，产生应力遮挡；Ｇａｍｍａ钉组钉棒末端出现超过正常值近一倍的压应变，而长柄Ｇａｍｍａ钉组却无应力集中。对比实验说明：对于不稳定型转子间骨折，髓腔内固定较其它方法好，更符合生物力学要求。Ｇａｍｍａ钉远端的应力集中，可以通过延长其柄部至股骨髁使应力分散，以减少因应力集中引起的术后并发症。
Thirty fresh femoral specimens were divided into five groups consisting each of six specimens.One group was left as control and in the others. Eveans type Ⅳ unstable intertrochanteric fracture were produced and fixed with AO screws and plates, Richards nails, Gamma nails and modified long stem Gamma nails respectively.200～1600N load were applied in one leg in the standing position for the measurement of electric strain distribution in the femurs.The changes of the strain in the different groups were compared with that of the control.The results revealed that the strain in the lesser trochanter greatly increased in Richards nailing group and markedly decreased in the other three groups. In the medial cortex of the femur, just behind the end of the Gamma stem,the strain was almost doubled in comparison with that of the control, while there was no concentration stress found in the modified long stem Gamma nailing group, which indicated that the extended stem of Gamma nail can spread the stress and can lower the complication resulted from the concentration stress.
出处
《中华骨科杂志》
CAS
CSCD
北大核心
1997年第4期224-228,共5页
Chinese Journal of Orthopaedics
关键词
股骨骨折
内固定
生物力学
Proximal femur fracture Internal fixation Biomechanics
