Biology Mechanics Correlation Studies About Loop Land K-wire Diameter In Different Match In Simulating Body Lengthen Operating Condition

Objective: Observes the Ilizarov technology erternal fixation device to apply in simulating body lengthen operating condition, when K-wire(Kirschner wire) obtain invariablenes stress, the loop and K-wire's diameter in different match, measure the K-wire withstanding tensile stress, to searching the best matching about loop and K-wire's diameter for the bone growing.Method: Replaces the bone with the plastic stick (elasticity coefficient equal), In the plastic stick, using the three groups of different diameter K-wires drill through three groups of the different diameter erternal fixation device (four loops) on the plastic stick. Sum total nine groups, Fixes the plastic stick with the 8 piece K-wire on ertemal fixation device, Then switch off the plastic stick between pevious two groups of loops and next two groups of loops, Each group of outside fixed system plastic stick pulls pulls 5cm, The plastic stick breaks the end to pull 1m every time .repeated 6 times, Each group measured the tensile 30 times with the static state strain-gauging processing instrumental (YZ-22). Altogether measure 270 times. And carries on statistics processing.Result: The erternal fixation device (Sum total nine groups of loops), When the K-wire loads gives the stress is 500N, the K-wire receives the tensile stress gradually to increase with along with the plastic stick to pull unceasingly. The plastic stick breaks the end to pull start lcm equally. Tensile stress biggest group is 16.8cm inner diameter loop-1.0mm K-wire groop, It's 118.79±1.53N/mm~2, Tensile stress smallest group is 12.0cm inner diameter loop -2.0mm K-wire groop, It's 15.73±0.80N/mm~2. Compared with 9 groups of data, The tensile stress change has the significance difference (P<0.05)Conclusion: when the loop of the erternal fixation device's diameter is constant, the K-wire diameter is bigger, the K-wire receives tensile stress is smaller, the erternal fixation is more steady ;when the K-wire diameter is constant, the loop of the erternal fixation device's diameter is bigger, the K-wire receives tensile stress is bigger, The variety of the K-wire diameter and the loop both are to the influence of the K-wire tensile stress ,The variety of the K-wire diameter to the influence of the K-wire tensile stress is bigger the influence of the variety of the loop.