| Objective: Ilizarov ring external fixation was invented by Professor Ilizarov in the last century,and there have been many scholars in this field in various countries around the world,while studying and applying Ilizarov ring external fixation at the same time a large number of biomechanics Aspects of the study,and its continuous improvement.How to optimize Ilizarov external fixed overall frame structure,how to increase the stability of the external fixator,scholars have been pursuing the goal.It is further developed and updated on the basis of the original Ilizarov external fixation technology and is widely used in the field of orthopedic and traumatic orthopedics.This experiment is the application of biomechanical experiments,compared with hole-type bolts,trench bolts,hole-type bolts + gaskets,trench bolts + gaskets four different types of pin-on bolts fixed puncture on the Ilizarov ring external fixation system Biomechanical properties.Methods: Fourteen PE rods were used instead of human tibia.They were randomly divided into seven groups,labeled A-G in alphabetical order.Experimental combination of external fixation frame are the same material,to avoid all external factors on the experimental results of interference.All group models are fixed with Ilizarov external fixator.A,B,C and D are used in four groups: hole type bolt,groove type bolt,hole type bolt + gasket,groove type bolt + Needle bolts fixed through the needle,E,F,G three groups using the same bolt 10 Nm,13 Nm,16 Nm under the fixed torque.After the combination of components assembled,with a special tool to make tibial AO A3 fracture model.The effect of the vertical axial load force of different models was given by the loading experiment on the electronic test machine which could give the axial compressive load.The degree of displacement of the ends under different axial stresses was observed.After loading,The olive needle was replaced and assembled,and the model was subjected to a torsion test on a torsion test machine to determine the relative torsional angle of the ends at three different torques.Finally,the experimental data obtained by the recording instrument were analyzed by SPSS22.0 software,and the difference between the experimental groups was analyzed by the variance analysis.The difference in biomechanical properties of the Ilizarov external fixation device when comparing the four needle bolts to the olive needle.Results: In the axial compression experiment,under the vertical load of 600 N,800N and 1000 N.the fracture displacement of group A was 2.234 ± 0.144 mm,4.076 ± 0.184 mm,4.882 ± 1.189 mm,group B was 2.134 ± 0.134 mm,3.876 ± 0.164 mm,4.582 ± 1.169mm;Group C was 1.615 ± 0.028 mm,3.588 ± 0.073 mm,4.292 ± 0.106 mm;Group D was 1.315 ± 0.048 mm,3.376 ± 0.154 mm,4.182 ± 1.179 mm.Statistical analysis was performed using variance analysis.The change of the displacement of group B under different axial loads was smaller than that of group A,and the difference was significant(p <0.05).The results showed that group B was superior to group C,and group D was superior to group C in different axial loads,and there was a significant difference between the two groups(p <0.05),indicating that group D was better than group C;(P <0.05),indicating that group C was superior to group A,but the difference was significant(P <0.05).Where group D is optimal for axial load resistance.Under the vertical load of 600 N,800N and 1000 N after fixed with 10 Nm,13Nm and 16 Nm,respectively,The fracture displacement of group E was 2.245 ± 0.146 mm,4.079 ± 0.186,4.883 ± 1.190 mm.The fracture displacement of group F was 1.635 ± 0.038 mm,3.579 ± 0.085 mm and 4.294 ± 1.109 mm respectively.The G group was 2.126 ± 0.135 mm,3.877 ± 0.176 mm and 4.583 ± 1.168 mm respectively.Data were analyzed by variance analysis.The displacement of the distal group was different under different axial loads.The F group was smaller than the E group,and the difference was significant(p <0.05).Indicating that group F is better than group E.(P <0.05),indicating that F group was superior to G group.The difference between the two groups was higher than that of group G(P <0.05),indicating that group G was superior to group E in group E,and the difference was significant(P <0.05).Wherein the F group is optimal in terms of anti-axial load capacity.In the torsion experiment,under the torque of 5Nm,10 Nm and 15 Nm.the relative angle of fracture of group A was 3.795 ± 0.113 °,6.111 ± 0.107 ° and 11.654 ± 0.086 °;group B was 3.545 ± 0.194 °,5.550 ± 0.162 ° and 10.584 ± 0.170 °;group C was 3.144 ± 0.185 °,5.150 ± 0.133 ° and 10.284 ± 0.127 °;group D was 3.013 ± 0.173 °,5.013 ± 0.101 °,10.023 ± 0.021 °.(P <0.05),indicating that in the anti-torsional transformation of the D group than the C group(P <0.05),the difference between the two groups was lower than that of the C group it is good.The change of the angle of the distal end of group B was lower than that of group A at different torques(p <0.05),indicating that group B was superior to group A.The change of the angle of the group C in the group C was lower than that in the group A(P <0.05),indicating that the odds ratio of group C was better than that of group A Where group D is optimal in terms of torsion resistance.Respectively at 5Nm,10 Nm and 15 Nm after 10 Nm,13Nm and 16 Nm respectively.The fracture angle of group E was 3.792 ± 0.112 ° and 6.112 ± 0.108.group F was 3.533 ± 0.192 °,5.545 ± 0.160 ° and 10.572 ± 0.158 °,respectively.The angle of fracture in group G was 3.646 ± 0.165 °,5.834 ± 0.135 °,11.112 ± 0.128 °.The variance analysis of group F was lower than that of group E at different torques,and there was a significant difference between the two groups(p <0.05),indicating that group F had better anti-twisting ability than group E;(P <0.05),indicating that F group had better anti-torsion ability than G group;group G had different torsion under different torque(P <0.05),but there was a significant difference between the two groups(P <0.05)(P <0.05),indicating that group G had better anti-torsion ability than group E,and the difference was significant(P <0.05).Wherein the F group is optimal in terms of torsion resistance.Conclusion: 1,in the anti-axial compression,D group clamp bolt fixed external fixator than A,B,C group has Ilizarov ring external fixed frame has a stronger axial stiffness performance;in the same pin bolts fixed,different torque In the case of fixing bolts,where group F is optimal in terms of resistance to axial load.2,in the anti-torsion,D group clamp bolt fixed external fixator than A,B,C group has Ilizarov ring external fixator has a stronger anti-torsion performance.The same pin bolts fixed,different torque fixed bolts in the case of F group in the anti-torsional load capacity of the best. |
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