Bone screw

Abstract

The invention discloses a bone screw which comprises a screw rod body. Threads are arranged on the screw rod body. The threads include the front-segment thread and the rear-segment thread, wherein the front-segment thread and the rear-segment thread are mutually connected. The front-segment thread is a deep thread, and the rear-segment thread is a shallow thread. The outer diameter of the shallow thread and the outer diameter of the deep thread are equal, and the inner diameter of the shallow thread is larger than the inner diameter of the deep thread. The front end of the shallow thread is provided with a self-tapping groove. According to the bone screw, due to the fact that the self-tapping groove is designed, screw-in and screw-out torsion increased due to reducing of the shallow thread and the deep thread can be reduced, and therefore operation time can be reduced, the operation efficiency and the operation successful rate can be improved, and the risks of nail breaking or device damage are reduced.

Description

technical field [0001] The invention relates to a medical device, in particular to a bone screw. Background technique [0002] Bone screws are mainly used to treat a series of diseases such as spine and trauma in clinical orthopedics, and have good results. The threads on bone screws are generally divided into two parts, one part is a shallow thread in the cortical bone segment, and the other part is a deep thread in the cancellous bone segment. The inner diameter of the shallow thread and the deep thread of the traditional bone screw are the same, so when fixing the cortical bone, the strength of the screw body of the shallow thread part is not enough, and it is easy to break, while when fixing the cancellous bone, the part of the cancellous bone The thread is shallow and easy to loosen or come out. In order to solve the above shortcomings of the traditional bone screw, a new type of bone screw has appeared in the prior art, which makes the outer diameter of the shallow t...

AI Technical Summary

Problems solved by technology

However, this bone screw of the prior art adopts the above-mentioned variable-diameter design, although it solves the shortcomings of the traditional bone screw, it also produces new problems: after the variable-diameter design, the tooth front of the deep thread is relatively sharp, and the screw thread cannot be screwed. When screwing in, the resistance is small, but when screwed to the shallow thread at the back of the screw body, the screwing-in resistance is increased due to the increased width of the tooth front of the shallow thread, and the screwing-in torque is also increased, and with the shallow thread being screwed in, The more formed the greater the resistance

Therefore, the structural design of this bone screw in the current technology increases the torque of screwing in and out of the bone screw, which not only increases the difficulty of operation, but also easily breaks the nail or damages the instrument.

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