Design And Mechanical Test Of Percutaneous Posterior Lumbar Dynamic Stabilization System

Objective To develop a new percutaneous minimally invasive posterior lumbar dynamic stabilization system, clarifying its composition, structure and the principle features. To investigate its clinical feasibility by testing the mechanical stability compared with traditional rigid rod.Methods 1. Design the percutaneous minimally invasive posterior lumbar dynamic stabilization rod: We put forward design ideas, and draw blueprint. Zhejiang guangci company is commissioned to manufacture the sample. 2. The mechanical testing of percutaneous minimally invasive posterior lumbar dynamic stabilization rod comparing with the traditional rigid rod: Choose five dynamic rods and five rigid bars randomly as subjects, grouping them to do the compressive, tensile and torsion experiment(including the forward and reverse), impose on a different load by thetesting machine, record the dynamic rods and rigid rods’ displacement change and torsion change, handle the data in the computer, compare the parameters difference.Results 1. In the compressive test, under the physical load, the dynamic rods group’s flexion motion range is 15°, there are significant statistical difference in the range of flexion motion between dynamic rods group and rigid rods group(P<0.05). 2. In the tensile test, under the physical load, the dynamic rods group’s extension motion range is 0.48 mm, there are significant statistical difference in the range of extension motion between dynamic rods group and rigid rods group(P<0.05). 3. In the torsion test, under the physical load, the dynamic rods group’s torsion motion range is 6.11°, there are significant statistical difference in the range of torsion motion between dynamic rods group and rigid rods group(P<0.05).Conclusion 1. This system consistent with the concept of minimally invasive. 2. This dynamic stabilization system has good stabilizing effect and retain a better mobility range, and it also demonstrating that it is better than the traditional rigid rod in compressive, tensile and torsion according to the mechanical test, consistent with the concept of dynamicstabilization.