Pedicle screw with pullout resistance

Abstract

This patent discloses a pedicle screw with pull-out resistance. The pedicle screw consists of the lower end of the solid screw with threads, the upper end of the screw with a solid cylinder inside the peripheral auxetic structure, and a nail seat connected to the peripheral auxetic structure, as shown in Figure 1 . Utilizing the auxetic properties of the auxetic structure, the pedicle screw expands when it is pulled, increasing the stability of the pedicle screw and the vertebral body. At the same time, the auxetic structure is a porous structure, which is conducive to the growth of bone cells, promotes osseointegration, and accelerates the fusion of the pedicle screw and the vertebral body. The unique structure design also makes up for the lack of auxetic structural strength, so that the pedicle screw can not only realize the pull-out resistance, but also ensure the mechanical strength of the pedicle screw and improve the internal fixation effect. This structural design can be easily applied to the design of orthopedic medical devices.

Description

technical field [0001] The invention is applied to the field of orthopedic medical instruments, in particular to an anti-pullout pedicle screw. Background technique [0002] The pedicle screw is a minimally invasive internal fixation medical device used for the treatment of unstable fractures and dislocations of the thoracolumbar spine or combined paraplegia, spinal deformity, and spinal tumors. However, in daily life, the pedicle screw often loosens or prolapses under the action of the in vivo mechanical environment, resulting in failure of internal fixation. At present, the expansion screw can be placed with a smaller diameter, and the diameter of the screw can be enlarged after entering the screw hole, so that the screw rod and the component can be firmly connected to achieve stable fixation. Excessive local pressure on the tissue results in bone resorption, which eventually leads to screw loosening. Therefore, it is necessary to design a pedicle screw with good mechani...

AI Technical Summary

Problems solved by technology

However, in daily life, the pedicle screw often loosens or falls out under the action of the internal mechanical environment, resulting in internal fixation failure.

At present, the expansion nail can be inserted with a small diameter, and after entering the nail hole, the corresponding operation is performed to expand the diameter of the nail, so that the screw rod and the component can be firmly connected to achieve stable fixation, but the diameter of this type of expansion nail becomes larger after implantation in bone tissue, resulting in bone loss. Excessive local pressure on the tissue, bone resorption occurs, and eventually leads to screw loosening

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