Bone screw covered with soft material

Abstract

The invention provides a bone screw assembly covered with soft material. The bone screw assembly comprises a bone nail body and outer covering soft material body; the outer covering soft material body is provided with a cavity in the center; the cavity is an inverted round table cavity; smooth parts and protruding sawtooth parts are arranged at the outer covering soft material body with equal intervals and one smooth part is arranged between two protruding sawtooth parts, wherein the number of the protruding sawtooth parts is n and the number of the smooth parts is n-1. The bone screw comprises outer layer soft material and an inner layer rigid screw; during the process of implanting, interference fit is formed to firmly fix the bone screw and affected parts; smooth parts and protruding sawtooth parts are arranged at the outer covering soft material body with equal intervals so as to guarantee that the bone screw assembly will not rotate at will and broken bones can be firmly fixed.

Description

technical field [0001] The invention relates to a bone screw, in particular to a bone screw assembly coated with soft material. Background technique [0002] Screw internal fixation has a history of 100 years in the treatment of fractures, from common screws to screws with different pitches and rods, to hollow screws, hip screws, expansion screws, double-ended thread screws, locking screws, micro-motion screws, and even some Screws for specific parts (such as pedicle screws, etc.), or screws made of special materials (such as absorbable screws, etc.) can be described in various poses and with different changes. It can be used alone or as an essential equipment in conjunction with other various fixation systems (such as nail-plate system or intramedullary nail system, etc.). With the improvement of the concept and technology of fracture trauma diagnosis and treatment, the requirements for manufacturing and processing technology of internal fixation devices are also constantl...

AI Technical Summary

Problems solved by technology

[0003] Bone nails are used as internal fixation and implantation equipment. The selection of bone nails has always been one of the problems faced by orthopedic surgery. The existing bone nails are prone to loosening in bone tissue, and it is not easy to fix in bone tissue. At the same time, it will cause secondary trauma to bone tissue. CN201082188 discloses a kind of expansion bone nail. Although it can play a certain role in preventing slippage, it still has certain technical defects, and it cannot be self-decomposed and absorbed by the human body. , after the fracture heals, a second operation is required to remove it, causing secondary damage to the patient; in order to solve the appeal problem, CN104095677A discloses a high-strength combined self-degrading expansion bone nail, including a bone nail body made of pure magnesium or magnesium alloy It fits with the expansion-type internal thread cavity located outside the bone screw body; the middle part of the inner surface of the expansion-type internal thread cavity is a deep thread, and the front part is a shallow thread. The bone nail body has a narrow head and a wide tail. The cone shape of the outer surface of the cone has deep threads on the middle part of the cone, and shallow threads on the front part; the nail cap of the bone screw body is provided with an inner triangle or a grooved inner cavity connected with the nail body. The nail body is located in the expansion-type internal thread cavity. This invention effectively integrates degradability and avoids the slipping of the nail body. This invention alone can only prevent the screw from sliding up and down, but it is in the expansion-type internal thread cavity. There is no force in the direction of rotation around the central axis, which does not guarantee that it will not rotate. At the same time, the degradation rate of its pure magnesium or magnesium alloy in the body is much faster than that of polylactic acid, so that the mechanical properties of magnesium alloy cannot be well reflected. , and when the polylactic acid and magnesium alloy materials are tightly matched, the polylactic acid needs to be compressed to cause brittle fracture and cannot effectively fix the broken bone

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