Repair of femoral shaft fracture with bridging combined internal fixation and locking plate screw system：a biomechanical comparison / 中国组织工程研究

ABSTRACT

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 colected 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 smaler 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 smaler in the bridging combination group than in the locking plate screw group (P < 0.05). (4) These results suggested thatin 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 smaler displacement, suggesting good deformation resistance under compressive stress, anteflexion and retroflexion stress.