Wedge screw internal fixation device

Abstract

The invention discloses a wedge screw internal fixation device, which comprises a lower wedge screw, an upper wedge inclined circular tube and a personalized bone plate. The lower wedge screw comprises an oblique cylindrical small screw section and an oblique cylindrical large screw section connected in sequence, wherein the top surface of the oblique cylindrical small screw section is provided with a cross-shaped groove, and the outer wall of the oblique cylindrical small screw section is provided with external thread; the oblique cylindrical large screw section is provided with an inclined surface, and the outer wall of the oblique cylindrical large screw section is provided with a self-tapping screw thread. The upper wedge oblique circular tube is provided with a channel along the axialdirection, the oblique cylindrical small screw section passes through the channel with a cylindroid structure and is sleeved in the upper wedge oblique circular tube from bottom to top, the outer diameter of the oblique cylindrical large screw section is equal to the outer diameter of the upper wedge oblique circular tube, and the inclined angle of the inclined plane of the upper wedge oblique circular tube is equal to the inclined angle of the inclined plane in the oblique cylindrical large screw section. The personalized bone plate is provided with screw thread holes, which have internal thread matched with oblique cylindrical small screw section. The structure is designed based on the characteristics of human bones, is simple and efficient to install, has short operation time in use, can be permanently fixed for osteoporosis patients, and is safe and reliable.

Description

technical field [0001] The invention relates to the technical field of medical instruments, in particular to a wedge screw internal fixation device. Background technique [0002] Bone is divided into cortical bone and cancellous bone. Cortical bone is also called compact bone, which keeps the bone hard and dense, and is distributed on the surface of the bone to maintain the hard and dense bone. The bone density of cancellous bone is lower than that of cortical bone, which is spongy. Shaped, elastic, distributed inside the bone. Osteoporosis, or osteoporosis, is a group of bone diseases caused by a variety of reasons. Bone tissue has normal calcification, and the ratio of calcium salt to matrix is ​​normal. It is a metabolic bone lesion characterized by a decrease in the amount of bone tissue per unit volume. . [0003] In the case of osteoporosis, the requirements for bone screws are even higher. There are still deficiencies in the bone screws that are currently clinicall...

AI Technical Summary

Problems solved by technology

There are still deficiencies in the bone screws that are currently clinically applicable to osteoporosis: 1) the size of the existing bone screws is limited by the width of the bone plate. The lack of pull-out resistance and shear resistance of the screw, especially in the case of severe osteoporosis, the possibility of bone screw fastening failure is greater; 2) in the prior art, there are also variable pitch or external diameter Bone screws are used to fix loose bone, but the operation is more difficult. For patients with loose bone, the thinner cortical bone bears the main pull-out force and frictional force of the screw. At this time, once the cortical bone If the stress at the cortical bone is too large, the threaded connection at the cortical bone will most likely fail. Only relying on the cancellous bone to bear the pull-out force and friction of the screw will eventually cause the screw to loosen or even break, which in turn will lead to failure of the internal fixation. fail

[0004] At the same time, fracture is the most common and serious complication of osteoporosis. At present, in the internal fixation of osteoporotic fractures, most cancellous bone screws are used for fixation. Although the contact area of ​​the bone improves the pull-out resistance and friction of the screw to a certain extent, due to the long-term and repeated contact and extrusion of the screw and the bone, if things go on like this, the final pull-out resistance of the screw will inevitably be insufficient and eventually lead to internal fixation failure

There are also some cases that use bicortical bone screws for fixation, but this method is very likely to cause secondary damage to the soft tissue on the opposite side of the bone, and operations such as drilling, tapping, treatment of screw channels, and screw screwing are required during the operation, which is cumbersome. make patients more susceptible to infection

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