Thread non-continuous detachable expandable bone screw

Abstract

The invention relates to the technical field of medical apparatus and instruments, in particular to a thread discontinuous detachable expansion bone nail. The thread discontinuous detachable expansion bone nail is composed of an operational cap, a locating strip, thread strips, a conical threaded rod, a bone nail body, side grooves and an expansion hole. A pair of side grooves is formed in the side wall of the bone nail body. The two side grooves are communicated with the expansion hole. Each thread strip is arranged inside each side groove. The inner side wall and the outer side wall of each thread strip are respectively in an arc plane with threads. The directions of the threads of the outer walls of the two thread strips are opposite. The thread strips are in clearance fit with the side grooves where the thread strips are arranged, and can horizontally move inside the side grooves where the thread strips are arranged along the side direction. According to the thread discontinuous detachable expansion bone nail, possibility that the bone nail drops out along the clockwise direction or along the anti-clockwise direction, an fixing effect is improved, and meanwhile operation is simpler and more convenient to achieve, operation damage is smaller, and safety is higher.

Description

technical field [0001] The invention relates to the technical field of medical devices, in particular to a thread discontinuous detachable expandable bone nail. Background technique [0002] The problem of loosening of bone nails is a major problem in orthopedic surgery. The patent No. 200910059277.0 of the "reciprocal self-locking anti-loosening bone screw" and the patent No. 201010005355.1 of the "insert-type anti-loosening bone screw" both use the positional relationship of two screw sections with opposite screw threads to prevent bone loss. The technical effect of the nail loosening in the direction of the thread. But both of them have some technical defects that are difficult to be solved. [0003] In order to achieve the technical effect described by the "reverse-shun self-locking anti-loosening bone nail" with the patent number of 200910059277.0, the most critical technical link is to compare the "reverse-advancing head" in the sixth line from the bottom of the firs...

AI Technical Summary

Problems solved by technology

[0003] In order to achieve the technical effect described by the "reverse-shun self-locking anti-loosening bone nail" with the patent number of 200910059277.0, the most critical technical link is to compare the "reverse-advancing head" in the sixth line from the bottom of the first page of the document. A set of cross-shaped slots in the slot is aligned with the cross-shaped slots of the forward rod" Since the reverse feed head and the forward feed rod are in the same fixing hole, the reverse feed head inside has been blocked after the forward feed rod is screwed in , the operator cannot observe the position and direction of a set of cross-shaped slots in the reverse-entry head’s P-shaped slots. Rod cross-shaped slots aligned"? If this problem is not solved, how can the cutting strip be inserted into the slots of the advancing rod and the reverse advancing head simultaneously? If the cutting strip cannot be inserted, the positional relationship between the advancing rod and the reverse advancing head cannot be fixed

In the specification of this patent, no solution is proposed for the above-mentioned technical difficulties that require creative labor to solve

[0004] However, the two screws in the "insertion-type anti-loosening bone nail" with the patent number 201010005355.1 are screwed into the bone through the side walls close together, which facilitates the clear display of the rice-shaped slots on the top of the two screws during operation. In front of the operator, the operator can adjust the two slots to the same direction to facilitate knocking the inserts into the slots, but this technical solution increases the area of ​​bone damage by using two screws side by side. times, which increases the risk of bone fracture, so it is still an unadvisable technical solution

[0005] In addition, the above two solutions only solve the problem of how to lock the positional relationship of the two screws, but there is no practical and effective solution that can easily release the locking of the two screws, so it is very difficult to remove the bone nails in the above two solutions

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