桥接组合式内固定与金属锁定接骨板钉系统修复股骨干骨折的生物力学比较

Repair of femoral shaft fracture with bridging combined internal fixation and locking plate screw system:a biomechanical comparison

背景:临床对股骨干骨折进行修复的过程中,可以选择不同内固定方式,包括桥接组合式内固定系统与金属锁定接骨板钉系统。目的:比较桥接组合式内固定系统与金属锁定接骨板钉系统固定股骨干骨折的生物力学特性。方法:收集18个股骨标本,随机分为3组,每组6个,其中正常对照组不作任何处理,其余两组制备股骨干骨折模型,桥接组合组行桥接组合式内固定,接骨板钉系统组行金属锁定接骨板钉系统内固定。对3组标本进行生物力学测试,通过股骨压缩实验记录3组最大载荷500 N作用下的最大位移;通过股骨前屈实验记录3组最大载荷100 N作用下的最大位移;通过股骨后屈实验记录3组最大载荷100 N作用下的最大位移。结果与结论:1不同载荷下压缩实验:桥接组合组和接骨板钉系统组的最大位移均大于正常对照组,其中在最大载荷500 N下,桥接组合组和接骨板钉系统组的最大位移均显著大于正常对照组(P<0.05);且桥接组合组显著小于接骨板钉系统组(P<0.05);2不同载荷下前屈实验:桥接组合组和接骨板钉系统组的最大位移均大于正常对照组,其中在最大载荷100 N下,桥接组合组和接骨板钉系统组的最大位移均显著大于正常对照组(P<0.05);且桥接组合组显著小于接骨板钉系统组(P<0.05);3不同载荷下后屈实验:桥接组合组和接骨板钉系统组的最大位移均大于正常对照组,其中在最大载荷100 N下,桥接组合组和接骨板钉系统组的最大位移均显著大于正常对照组(P<0.05);且桥接组合组显著小于接骨板钉系统组(P<0.05);4结果表明,体外模拟股骨干骨折桥接组合式内固定系统与金属锁定接骨板钉系统均能获得一定的固定效果,设计符合生物力学原理,其中桥接组合式内固定在压应力以及前屈、后屈应力作用下,均可以保持较小的位移,提示具有较好的变形抵抗能力。

BACKGROUND：Different methods of internal fixation can be selected during the repair of femoral shaft fractures in the clinic,including bridging combined internal fixation and metal locking plate screw fixation.OBJECTIVE：To compare the biomechanical properties of bridging combined internal fixation and metal locking plate screw fixation for femoral shaft fracture.METHODS：Eighteen femoral samples were collected and randomly divided to three groups,with six in each group.In the normal control group,no treatment was given.In the other groups,models of femoral shaft fracture were established.In the bridging combination group,samples underwent bridging combined internal fixation.In the locking plate screw group,samples underwent metal locking plate screw fixation.Biomechanical test was conducted in samples of the three groups.In the femoral compression experiments,we recorded the maximum displacement under the maximal load 500 N.In the femoral flexion experiment,we recorded the maximum displacement under the maximal load of 100 N.In the femoral retroversion experiment,we recorded the maximum displacement under the maximal load of 100 N.RESULTS AND CONCLUSION：（1） Compression experiment at different loads：the maximum displacement was larger in the bridging combination group and locking plate screw group than in the normal control group.Under the maximum load of 500 N,the maximum displacement was significantly larger in the bridging combination group and locking plate screw group than in the normal control group（P〈0.05）.Moreover,the maximum displacement was significantly less in the bridging combination group than in the locking plate screw group（P〈0.05）.（2） Flexion experiment under different loads：the maximum displacement was larger in the bridging combination group and locking plate screw group than in the normal control group.Under the maximal load of 100 N,the maximum displacement was significantly larger in the bridging combination group and locking plate screw group than in the normal control group（P〈0.05）.Moreover,the maximum displacement was significantly smaller in the bridging combination group than in the locking plate screw group（P〈0.05）.（3） Retroflexion experiment under different loads：the maximum displacement was larger in the bridging combination group and locking plate screw group than in the normal control group.Under the maximal load of 100 N,the maximum displacement was significantly larger in the bridging combination group and locking plate screw group than in the normal control group（P〈0.05）.Moreover,the maximum displacement was significantly smaller in the bridging combination group than in the locking plate screw group（P〈0.05）.（4） These results suggested that in vitro simulated femoral shaft fracture bridging combination fixation and metal locking plate screw system can obtain good fixation effect;the design meets the principle of biomechanics.Among them,bridging combined internal fixation can maintain a smaller displacement,suggesting good deformation resistance under compressive stress,anteflexion and retroflexion stress.