【摘要】 目的:分析比较髋臼后壁骨折3种内固定方法的生物力学稳定性,为临床髋臼后壁骨折的内固定治疗提供参考。方法:成人半骨盆-股骨固定标本28具,随机分为A、B、C、D4组,A组为结构完整组,余3组制作髋臼后壁2/3骨折,其中B组采用重建钢板固定,C组采用拉力螺钉固定,D组采用V形钢板固定。用万能材料实验机测定负荷加载下后壁骨块的应力变化,最大载荷设置为3000N。从计算机读取负荷在300N,600N,900N,1200N,1500N,1800N,2100N,2400N,2700N,3000N时的应变数值,以A组为对照组,将A,B,C,D各组数据进行统计学比较。结果:在负荷从0加载至1200N时,3种内固定方法的应变值与正常组差异无统计学意义(P>0.05)。负荷加载超过1200N时,C、D组与A组的应变值比较明显减少,而B组与A组比较,总体应力变化趋势相似;C、D两组的应变值比较差异无统计学意义。结论:3种内固定方法均有一点的抗压强度可适于髋臼后壁骨折术后早期部分负重的功能锻练;重建钢板的固定強度较大,有利于早期较大负重的锻练。V形钢板固定为临床治疗髋臼后壁骨折提供了1种新的选择方法。更多还原

【Abstract】 Objective:To compare three different internal fixation strengths of the fractures of the posterior wall of the acetabulum by biomechanical testing to provide evidence for choice of clinical treatment.Methods:Twenty-eight hemipelves articulated proximal one-third of femur were harvested from embalmed cadavers of human adults.The whole specimens were divided into four groups randomly.Group A was with normal construction of hip joint and set up as control group, and the other groups were with operatively created fracture of 2/3 areas of the posterior wall.The fractures were anatomically reduced and fixed as follows:group B with reconstruction plate;group C with lag screws alone;group D with V-shaped plate.Each specimen was tested by materials-testing system and sequent loads on pelvis ranged from 0 to 3 000 Newtons.The actuator loads were directly recorded by computer, and the output from the pressure-sensitive patch that was attached to the fragment was transmitted to a converter which connected with the same computer.The data of load and corresponding strain were obtained from the computer.The statistical comparisons between each group were analyzed using ANOVA with the level of significance set at P=0.05.Results:When the loads were lower than 1 200 N, the strains of three internal fixations had no significant change compared with the control group respectively(P>0.05).As testing loads increased the strains of group C and group D reduced significantly(P<0.05), compared with group A, while the total variational tendency of strains of group B was parallel to group A(P>0.05).There were on statistical differences between group C and group D(P>0.05).Conclusion:At the lower loading situation the strengths of fracture fixed with lag screws alone or V-shaped plate are similar to normal group, which may infer that both of these fixations can be suitable for early passive exercises or moderate weightbearing exercises after surgery of the fracture of the posterior wall of the acetabulum.The repairing technique of reconstruction plate is a stranger fixation that may resist heavier weightbearing mobilization than other tow fixations.This experimental outcomes also indicate that the new technique of V-shaped plate fixation provides an alternative in terms of the treatment of the fracture of the posterior wall of the acetabulum.更多还原