Application of self-designed adjustable kyphoplasty device in thoracolumbar fractures

English Keywords:Kyphoplasty device  Thoracolumbar fractures  Kyphoplasty  Biomechanics

English Abstract:

  【Abstract】 Objectives: To develop a new type of titanium alloy adjustable kyphoplasty device, and to explore its use in the treatment of thoracolumbar vertebral compression fractures. Methods: The lantern-shaped elastic metal ball was made by using the super elastic titanium. After some procedures, the metal ball could endure some distraction and retraction. Applications INSTRON 5544 were used to test the maximum load and stress change by self-designed equipment. 5 normal fresh adult thoracolumbar spine specimens(T12-L2) were used, a self-curing denture powder was embedded in the specimens, and L1 vertebral body and its upper and lower discs were exposed. The specimens were placed in biomechanical testing machine INSTRON 8874 base at flexion 10°, a ball hydraulic loading in quasi-static loading was performed. Then the specimens were transferred into L1 vertebral traumatic fracture models. The adjustable kyphoplasty device was placed in the vertebral bodys, the terminal adjustable device was rotated for distraction and achieve reduction. After that, type Ⅲ acrylic bone cement was infilled in the defect from bilateral pedicle. Results: (1)The initial diameter of lantern-shaped metal ball was 6.0mm, and after rotating the adjustable device, the maximum diameter reached 12mm, the maximum stress load of a single piece was 56.96±3.21N, the stress was 9.48±0.53MPa. (2)After reaming with a diameter of 6.5mm reamer, the kyphoplasty with 6mm diameter could be placed in vertebral body through the pedicle and finish expansion with average height restoration of 98.95%. Conclusions: Adjustable kyphoplasty device is of elasticity and flexibility, which can be used for the treatment of thoracolumbar vertebral fractures.