Assembly method of low profile screw seat and positioning pressure ring

Abstract

A low-profile screw seat, which relates to the technical field of pedicle screws for orthopedic surgery, is characterized in that a groove for accommodating a positioning pressure ring and a limiting convex ring is arranged above the engaging protrusion, and its inner diameter is larger than the limit of the positioning pressure ring The diameter of the protruding ring; the upper part of the ring body on the left and right sides of the rod slot is provided with a limiting protruding ring that protrudes outwards and matches the engaging protrusion, and the outer wall of the ring on the upper or lower side of the limiting protruding ring is provided with The anti-rotation protrusion protrudes outward, and the locking protrusion is provided with an anti-rotation card slot matched with the anti-rotation boss. Its installation method is: when the limit convex ring of the positioning pressure ring is opposite to the two U-shaped grooves, it is inserted from the top of the assembly hole downward into the groove between the internal thread in the main body of the nail seat and the locking protrusion, and then rotate The positioning pressure ring is inserted into the groove between the internal thread on the inner wall of the main body of the nail seat and the locking protrusion, and the anti-rotation boss is opposite to the anti-rotation card groove, and the positioning pressure ring is punched downward. The invention has the advantages of small diameter, low notch and the like.

Description

technical field [0001] The invention relates to the technical field of pedicle screws for orthopedic surgery, and in detail relates to an assembly method of a small-diameter, low-profile low-profile screw seat and a positioning pressure ring. Background technique [0002] Existing pedicle screws are mainly divided into three types: uniaxial pedicle screws, universal pedicle screws and uniplanar pedicle screws. The existing universal pedicle screw and uniplanar pedicle screw are composed of a ball head screw and a screw seat matched with it, wherein the screw seat includes a screw seat main body and a positioning pressure ring, and the screw seat main body is provided with a longitudinally penetrating assembly The upper part of the main body of the nail seat is provided with a U-shaped groove for piercing the connecting rod, the inner wall of the main body of the nail seat on both sides of the U-shaped groove is provided with internal threads, and the inner wall of the main b...

AI Technical Summary

Problems solved by technology

Since the deformation of the stamping during the assembly process is not easy to be accurately controlled, the drilling depth on the side of the nail seat also has a certain tolerance range during large-scale production, so the height and thickness of the bumps vary during the production process

When the height and thickness of the bump are small, the screwdriver is easy to bring out the positioning pressure ring during the operation, causing the screw parts to scatter and fail

At the same time, because the shape of the convex point is a circular arc, when the nail driver is pulled upward with a large force, it is easy to squeeze the convex point back to the side hole of the screw seat, resulting in the disintegration of the screw already implanted in the human body

Such problems occur from time to time during the operation, which poses a huge hidden danger to the safety of the operation.

At the same time, the side wall of the screw seat and the side of the positioning pressure ring are the stressed parts. After the screw is tightened, the stress is relatively large. The side holes and grooves will affect the strength of the screw. In order to meet the strength requirements of the use, the size of the screw seat is often relatively large. , adversely affect the healing of the patient's surrounding tissue

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