Medical vertebral pedicle strengthening screw

Abstract

The invention discloses a medical vertebral pedicle strengthening screw consisting of a screw sleeve and a self-tapping screw in mutual fit, wherein, the screw sleeve is made from medical absorbable materials and has certain mechanical strength and toughness; the medical absorbable materials can effectively maintain the mechanical strength in vivo for 2 to 3 months; the screw sleeve is divided into a head end, a middle section and a tail end, wherein, the head end of the screw sleeve is sealed up and in a hemispherical shape, the middle section is provided with a longitudinal crack, and a cone-shaped hollow cavity is formed at the tail end thereof; and the self-tapping screw is made of medical titanium alloy and consists of a thread section and a tail part, wherein, the thread section is formed by connecting a cone-shaped tip part and a cylinder in external-thread design, a U-shaped groove penetrating in a radial direction is formed at the tail part, and internal threads are formed on the inner wall of the U-shaped groove. The invention is able to improve the stability of internal fixation in the process of the primary screw placement in an osteoporosis situation and reduce the incidence that the pedicle screw becomes loosened or even prolapsed, thus enhancing the stability and reliability of the internal fixation of spines and lowering the failure rate of operations.

Description

technical field [0001] The invention belongs to medical auxiliary equipment, and relates to a pedicle screw used in spinal internal fixation, in particular to a medical pedicle reinforcement screw, which is mainly used to improve the stability of internal fixation during the initial screw placement under the condition of osteoporosis. Reduce the risk of internal fixation failure. Background technique [0002] At present, transpedicular internal fixation has become a routine technique in spinal surgery. Pedicle screws can be used for three-dimensional correction of spinal deformity and reconstruction of spinal stability by means of traction, compression, and rotation. The key to the stability of pedicle screw fixation depends on whether sufficient "bone-screw" interface holding force can be obtained, and this holding force must last until solid bony fusion between vertebral bodies is achieved. However, in clinical work, osteoporosis often leads to a decrease in the fixation...

AI Technical Summary

Problems solved by technology

[0004] 1. After the bone cement is perfused, the bone cement material and the screw are tightly bonded, and it is extremely difficult to remove the cured screw, causing damage to the surrounding tissue;

[0005] 2. Bone cement is difficult to degrade in the body, and a secondary interface of "screw-bone cement-bone" will be formed. It is difficult to achieve bony healing between nails and bones, and it cannot maintain long-term stability in the body. There are great limitations in clinical application. Security risks;

[0006] 3. More importantly, injecting material into the screw channel and the surrounding bone through various methods is likely to cause leakage, space-occupying lesions, and serious complications

Even if absorbable materials are used, and the dose and pressure of injected materials are carefully controlled during the operation, the occurrence of leakage cannot be completely avoided, which brings great challenges to the operation of the surgeon and largely limits the clinical application. widely cited

[0007] In improving the screw design, increasing the screw diameter may lead to the risk of pedicle fracture, and the use of long screws may damage the anterior column of the vertebral body, which may cause visceral and blood vessel damage.

Although the currently used expandable pedicle screws can significantly improve the stability of internal fixation under the condition of osteoporosis, the screw is in an expanded state for a long time in the body, resulting in plastic deformation, and at the same time, new bone continues to grow into the gap in the expanded part. In the process of taking out the screw, even if the inner plug is pulled out, the expansion part of the front end of the screw cannot be retracted, which brings great difficulties to taking out the screw. If it is taken out forcibly, it will cause a large range of bone destruction and seriously affect the stability of the spine. sex

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