Extractor with conical sharp tool bit and compression device and used for extracting screws with worn-out threads

Abstract

The invention relates to an extractor with a conical sharp tool bit and a compression device and used for extracting screws with worn-out threads and belongs to the technical field of medical apparatus and instruments for the orthopaedics department. The extractor comprises a T-shaped handle and a compression clamp. The conical sharp tool bit is connected to the front end of the T-shaped handle. The T-shaped handle is further provided with a spherical nut and a hexagon nut. The upper end of the compression clamp is provided with a U-shaped clamp groove, the lower end of the compression clamp is provided with a U-shaped clamp seat, and the U-shaped clamp groove is connected with the U-shaped clamp seat through a connecting rod. The U-shaped clamp groove can clamp the spherical nut. The U-shaped clamp seat clamps the lower portion of the groove of the screw with the worn-out thread. The extractor is simple in structure, high in success rate, less prone to thread wear, simple to operate, free of bone destruction, free of metal chip residues, and the like. Most importantly, the compression clamp can tightly keep the conical sharp tool bit in the groove of the screw with the worn-out thread without external force, slipping cannot occur easily during extracting, and a high extracting rate is achieved.

Description

technical field [0001] The invention relates to a tapered sharp cutter head sliding thread screw extractor with a pressing device, which belongs to the technical field of orthopedic medical instruments. Background technique [0002] Bone plate and screw fixation of fractures have become the most commonly used internal fixation methods today. At present, hexagon socket screws are the most commonly used screws in orthopedics. After the fracture has healed, the bone plate screws in the body need to be removed. Because the screw bears a large stress in the body, the frictional resistance of the screw increases greatly. It is very laborious to unscrew the screw and the screw often slips. Especially in recent years, with the widespread use of locking screws, the nail holes and There are fine threads between the tails of the matching locking screws. During the weight-bearing activities of the affected limb after fracture healing, the screw is more likely to deform the thread betwe...

AI Technical Summary

Problems solved by technology

Because the screw bears a large stress in the body, the frictional resistance of the screw increases greatly, and it is very laborious to unscrew the screw and the screw often slips. Especially in recent years, with the widespread use of locking screws, the nail holes and There are fine threads between the tails of the matching locking screws. During the weight-bearing activities of the affected limb after the fracture heals, the screw is more likely to deform the thread between the screw tail and the locking hole on the bone plate due to the stress on the screw. It is more difficult to get out, and the chance of slipping the screw during strong rotation is greatly increased

[0003] Screw slippage will significantly increase the difficulty of removal, prolong the operation time, increase the chance of infection, failure of removal and even serious complications such as refracture

Existing tools such as tapered reverse screw thread tapping and plum-shaped screwdriver cannot keep the screwdriver tightly pressed in the inner hexagonal groove of the slide wire, and external force is required to keep the screwdriver tightly pressed in the slide wire In the hexagonal groove

When taking it out, the user has to rotate it vigorously, but also forcefully press it downward to keep the screwdriver tightly pressed in the inner hexagonal groove of the sliding wire.

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