猪胫骨髁间嵴骨折三种内固定方法的抗拉力实验研究

Study on three internal fixation methods applied in tensile resistance of porcine tibial eminence avulsion fracture fixation

目的比较螺钉、钢丝、张力带三种固定方法在猪胫骨髁间棘突骨折固定中的抗拉力作用,探讨三种固定方法治疗胫骨髁间嵴撕脱骨折的可靠性。方法取新鲜猪腿关节部15个,制备Meyers Mckeever骨折分型中Ⅲ型骨折模型,按固定方式分为3组(n=5),依次为螺钉组、钢丝组、张力带组。用测力仪监测标本的抗拉力情况,直至固定失败;测量标本最大拉力负荷量。结果螺钉组:拉力负荷(894.00±199.08)N时,5例螺钉全部松动或拔出。钢丝组:拉力负荷(1 111.20±82.73)N时,3例出现松动,2例出现骺离骨折。张力带组:拉力负荷(1 229.20±112.01)N时,5例出现骺离骨折,固定无松动。方差分析结果,F=7.35,P=0.0083,差异具有统计学意义,可以认为三组总体均数不全相同。两两比较结果:螺钉组与钢丝组比较差异有统计学意义,螺钉组与张力带组比较差异有统计学意义,而钢丝组与张力带组比较差异无统计学意义。虽然钢丝组、张力带组统计上无明显差异,但从出现松动率上,在拉力超过1 100 N并继续增加拉力时,钢丝组出现3例松动(60%),2例骶离骨折。而张力带固定的骨折块无松动,全部出现骺离骨折,说明张力带组固定较单纯的钢丝固定要可靠。结论在本组试验中螺钉固定抗拉力能力最差,钢丝次之,克氏针钢丝张力带固定最可靠。

Objective To compare three internal fixation methods by screws,steel wire and Kirschner wire tension band applied in tensile resistance of porcine tibial eminence avulsion fracture fixation,and to explore the reliability of these methods on the tibial eminence avulsion fracture’s treatment.Methods Fifteen fresh porcine knee joints were selected,then preparation models of Meyers Mckeever Ⅲ type fracture were made.They were divided into 3 groups(n=5)including the screw group,the steel wire group,and the tension band group according to the fixation mode.Tensile resistance on specimens was monitored by CL-2 dynamometer until fixation failure in order to measure the maximum failure load.Results In the crew group,when tension load was(894.00±199.08)N,5 of screws were loosened or pulled out entirely.In the steel wire group,when tensile load was(1 111.20±82.73)N,3 were relaxed and 2 were with Salter-Harris fractures.In the tension band group,when tension load was(1 229.20 ±112.01)N,5 were with Salter-Harris fractures and they were fixed without loose.Variance analysis showed F=7.35,and P=0.008 3,and the difference was statistically significant.The difference of the screw group and the steel wire group was statistically significant,and the difference of the screw group and the tension band group was statistically significant,while the difference of steel wire group was no statistically significant compared with the tension band group.Although there is no obvious difference of the steel wire group and the tension band group,3 cases(60%)appeared to be loosen,2 cases of Salter-Harris fractures of steel wire group when more than 1 100 N in tension and continuing to increase tension.However fixation by tension band was not loose,and all showed Salter-Harris fractures.Conclusion We concluded that the tension band fixed for tibial eminence avulsion fracture was more reliable than the steel wire and screws.