Degradable material minimally invasive bone screw

Abstract

The utility model provides a kind of degradable material minimally invasive bone screw, including screw body, the upper end of screw body is fixedly connected with top locking sheet, the outside of screw body is fixedly connected with locking screw thread, the inside of screw body is equipped with internal storage cavity, the inner end of internal storage cavity is fixedly connected with water-soluble inner layer, the inner end of water-soluble inner layer is provided with storage component, the inner wall thickness of multiple degradable storage inner bin is arranged in decreasing from top to bottom, and the length of water-soluble jamming corresponds to the inner wall thickness of corresponding degradable storage inner bin, in the process of tissue fluid penetration and dissolution, water-soluble jamming of upper degradable storage inner bin is dissolved first, so that gelatinous liquid flows out from different degradable storage inner bin in turn, avoid all release of medicine, can be according to the demand of different stages of fracture healing, realize the orderly, controllable release of medicine, improve the pertinence and effectiveness of drug treatment.

Description

Technical Field

[0001] This utility model relates to a biodegradable minimally invasive bone screw, belonging to the field of medical device technology. Background Technology

[0002] Biodegradable minimally invasive bone screws are a new type of orthopedic medical device primarily used for internal fixation of fractures, while also possessing drug delivery capabilities. In terms of materials, the screw body and related structures are made of biodegradable materials. After fulfilling their function of fixing the fracture, these materials gradually degrade in the body's physiological environment and are eventually absorbed or excreted, avoiding the inconvenience and risks of requiring a second surgery to remove traditional metal bone screws.

[0003] A biodegradable tension bone screw, patent number CN201353194Y, comprises a screw shank and a screw cap. The screw shank and screw cap are integrally formed from magnesium and its alloys. The front section of the screw shank has external threads, and the rear section is a cylindrical shape. This bone screw, made of magnesium and its alloys, effectively provides tension and compression, which is beneficial for inducing bone growth between bone fragments, stabilizing the bone fracture ends, and promoting fracture healing. The screw cap has a countersunk hole on its end face, allowing for convenient insertion of the bone screw into the bone using appropriate instruments, making the operation convenient.

[0004] The fracture healing process requires not only stable mechanical support but also drug-assisted treatment. To address these issues, drug-delivered biodegradable minimally invasive bone screws have emerged. However, existing products still have many shortcomings, such as difficulty in precisely controlling drug release and the inability of most products to release the appropriate dose of drug according to different stages of fracture healing.

[0005] To address this, a biodegradable minimally invasive bone screw is proposed. Utility Model Content

[0006] In view of this, the present invention provides a biodegradable minimally invasive bone screw to solve or alleviate the technical problems existing in the prior art, and at least provides a beneficial option.

[0007] The technical solution of this utility model is implemented as follows: A biodegradable minimally invasive bone screw includes a screw body, a top locking plate fixedly connected to the upper end of the screw body, a locking thread fixedly connected to the outer side of the screw body, an internal storage cavity opened on the inner side of the screw body, a water-soluble inner layer fixedly connected to the inner end of the internal storage cavity, a drug storage component provided at the inner end of the water-soluble inner layer, the drug storage component includes multiple biodegradable drug storage chambers connected at equal intervals from top to bottom, the inner wall thickness of the multiple biodegradable drug storage chambers decreases from top to bottom, bottom overflow holes are symmetrically opened at the left and right ends of the biodegradable drug storage chambers, water-soluble plugs are plugged at the inner end of the bottom overflow holes, the length of the multiple water-soluble plugs corresponds to the inner wall thickness of the corresponding biodegradable drug storage chamber, the inner end of the biodegradable drug storage chamber is filled with a number of gel liquids, the gel liquids flow out through the bottom overflow holes, and side vertical grooves are symmetrically opened on the front and rear inner walls of the biodegradable drug storage chambers.

[0008] More preferably, a follower inner column is slidably connected to the upper inner end of the biodegradable drug storage compartment, and an extended sliding inner block is symmetrically fixedly connected to the front and rear ends of the follower inner column.

[0009] More preferably, the sliding inner block is slidably connected to the side vertical slide groove, and a protruding rubber ring is fixedly connected to the lower outer side of the follower inner column plate.

[0010] More preferably, the protruding rubber ring is in contact with the inner wall of the biodegradable drug storage compartment, and the moving inner column is located above the gel liquid.

[0011] More preferably, the inner end of the screw body is fixedly connected with a plurality of reinforcing inner columns, which are arranged in a ring at equal intervals.

[0012] More preferably, the outer end of the water-soluble plug is fixedly connected with an external anti-detachment texture, and the inner sidewall of the bottom overflow hole is fixedly connected with an internal anti-detachment texture.

[0013] More preferably, the water-soluble plug and the bottom overflow hole are interconnected through an outer anti-detachment texture and an inner anti-detachment texture.

[0014] The present invention has the following advantages due to the adoption of the above technical solution:

[0015] I. This utility model features multiple biodegradable drug storage chambers with decreasing inner wall thickness from top to bottom. The length of the water-soluble plug corresponds to the inner wall thickness of the corresponding biodegradable drug storage chamber. During the tissue fluid penetration and dissolution process, the water-soluble plug in the upper biodegradable drug storage chamber dissolves first, allowing the gel fluid to flow out sequentially from different biodegradable drug storage chambers. This avoids the release of all the drug at once, enabling the orderly and controllable release of the drug according to the needs of different stages of fracture healing, thereby improving the targeting and effectiveness of drug treatment.

[0016] Second, this utility model, during the outflow of the gel liquid, has extended sliding inner blocks at both ends of the moving inner column slide downward along the side vertical groove, and the protruding rubber ring is always in close contact with the inner wall of the biodegradable drug storage chamber. It can slide down as the gel liquid decreases, pushing out as much of the gel liquid as possible, effectively avoiding drug residue in the biodegradable drug storage chamber, and ensuring that the drug is fully utilized.

[0017] Third, this utility model ensures that the outer anti-detachment texture of the water-soluble plug and the inner anti-detachment texture of the bottom overflow hole interlock with each other, so that the water-soluble plug can be firmly plugged in the bottom overflow hole before it dissolves, preventing premature leakage of the gel liquid, ensuring that the drug release process proceeds according to the design process, and improving the accuracy and safety of drug release.

[0018] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the screw body structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the internal structure of the screw body of this utility model;

[0022] Figure 3 This is a schematic diagram of the drug storage component structure of this utility model;

[0023] Figure 4 This is a partially truncated enlarged structural diagram of the upper part of the drug storage component of this utility model;

[0024] Figure 5 This is a schematic diagram of the water-soluble stopper structure of this utility model.

[0025] Reference numerals: 1. Screw body; 2. Locking thread; 3. Top locking plate; 4. Reinforcing inner column; 5. Water-soluble inner layer; 6. Drug storage component; 7. Biodegradable drug storage compartment; 8. Bottom overflow hole; 9. Water-soluble plug; 10. Gel liquid inside; 11. Side vertical groove; 12. Follow-up inner column plate; 13. Extended sliding inner block; 14. Outer protruding rubber ring; 15. Outer anti-slip texture; 16. Inner anti-slip texture; 17. Internal storage cavity. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0027] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0028] Example 1

[0029] like Figure 1-4 As shown, this utility model embodiment provides a biodegradable minimally invasive bone screw, including a screw body 1. A top locking plate 3 is fixedly connected to the upper end of the screw body 1. A locking thread 2 is fixedly connected to the outer side of the screw body 1. An internal storage cavity 17 is formed on the inner side of the screw body 1. A water-soluble inner layer 5 is fixedly connected to the inner end of the internal storage cavity 17. A drug storage component 6 is provided at the inner end of the water-soluble inner layer 5. The drug storage component 6 includes multiple biodegradable drug storage compartments 7 connected equidistantly from top to bottom. The thickness of the inner wall between the biodegradable drug storage chambers 7 decreases from top to bottom. The left and right ends of the biodegradable drug storage chambers 7 are symmetrically provided with bottom overflow holes 8. The inner end of the bottom overflow hole 8 is plugged with a water-soluble plug 9. The length of the multiple water-soluble plugs 9 corresponds to the thickness of the inner wall of the corresponding biodegradable drug storage chamber 7. The inner end of the biodegradable drug storage chamber 7 is filled with a number of gel liquids 10. The gel liquids 10 flow out through the bottom overflow holes 8. The front and rear inner walls of the biodegradable drug storage chambers 7 are symmetrically provided with side vertical grooves 11.

[0030] A follower inner column plate 12 is slidably connected to the upper inner end of the biodegradable drug storage chamber 7. Extended sliding inner blocks 13 are symmetrically fixed to the front and rear ends of the follower inner column plate 12. The extended sliding inner blocks 13 are slidably connected to the side vertical sliding groove 11. An outwardly protruding rubber ring 14 is fixedly connected to the outer side of the lower end of the follower inner column plate 12. The outwardly protruding rubber ring 14 is in contact with the inner side wall of the biodegradable drug storage chamber 7. The follower inner column plate 12 is located above the gel liquid 10.

[0031] Example 2

[0032] like Figure 2 ,5 As shown, in one embodiment, the inner end of the screw body 1 is fixedly connected with a plurality of reinforcing inner columns 4, which are arranged in a ring at equal intervals. The outer end of the water-soluble plug 9 is fixedly connected with an outer anti-detachment texture 15, and the inner sidewall of the bottom overflow hole 8 is fixedly connected with an inner anti-detachment texture 16. The water-soluble plug 9 and the bottom overflow hole 8 are interconnected through the outer anti-detachment texture 15 and the inner anti-detachment texture 16.

[0033] The outer anti-detachment groove 15 at the outer end of the water-soluble plug 9 interlocks with the inner anti-detachment groove 16 on the inner sidewall of the bottom overflow hole 8, ensuring that the water-soluble plug 9 is firmly plugged in the bottom overflow hole 8 before it dissolves, preventing premature leakage of the gel liquid 10. At the same time, the reinforcing ribs 4 inside the screw body 1 are arranged in a ring at equal intervals to maintain the structural strength of the screw and ensure the fixing function during the screw degradation and drug release process.

[0034] In operation, when the biodegradable minimally invasive bone screw is screwed into the bone setting position through the locking thread 2, it comes into contact with the human tissue fluid, initiating the drug release process. First, the water-soluble inner layer 5 of the screw body 1, due to the material properties of sodium alginate, interacts with the tissue fluid. Its molecular structure gradually disperses under the penetration of water molecules, forming a large-area solution. The dissolved liquid permeates into the drug storage component 6 and comes into contact with the water-soluble plug 9 in the bottom overflow hole 8. The polylactic acid-glycolic acid copolymer in the water-soluble plug 9 weakens its intermolecular forces under the wetting of the water, and gradually dissolves. Since the inner wall thickness of the multiple biodegradable drug storage chambers 7 decreases from top to bottom, and the length of the water-soluble plug 9 corresponds to the inner wall thickness of the corresponding biodegradable drug storage chamber 7, the inner wall of the upper biodegradable drug storage chamber 7 is thinner, and the water-soluble plug 9 dissolves first. After dissolution, the gel liquid 10 in the biodegradable drug storage chamber 7 flows out through the bottom overflow hole 8 under its own gravity and subsequent dissolution pressure, spreading towards the fracture site. During the outflow of the gel liquid 10, the follower inner column plate 12 plays a role. The extended sliding inner blocks 13 at both ends of the follower inner column plate 12 slide downward along the side vertical groove 11. The protruding rubber ring 14 is always in close contact with the inner wall of the biodegradable drug storage chamber 7. This structure ensures that the follower inner column plate 12 can slide down as the gel liquid 10 decreases, pushing out as much gel liquid 10 as possible and avoiding drug residue. As the gel liquid 10 in the upper biodegradable drug storage chamber 7 is completely released, tissue fluid continues to permeate and dissolve the water-soluble plug 9 corresponding to the lower biodegradable drug storage chamber 7. The above process is repeated, so that the gel liquid 10 flows out from different biodegradable drug storage chambers 7 in sequence, realizing the orderly release of drugs.

[0035] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A biodegradable minimally invasive bone screw, comprising a screw body (1), characterized in that: A top locking plate (3) is fixedly connected to the upper end of the screw body (1), and a locking thread (2) is fixedly connected to the outer side of the screw body (1). An internal storage cavity (17) is opened on the inner side of the screw body (1). A water-soluble inner layer (5) is fixedly connected to the inner end of the internal storage cavity (17). A drug storage assembly (6) is provided at the inner end of the water-soluble inner layer (5). The drug storage assembly (6) includes multiple biodegradable drug storage chambers (7) that are equidistantly connected from top to bottom. The thickness of the inner wall between the multiple biodegradable drug storage chambers (7) is increasing from top to bottom. The biodegradable drug storage chamber (7) is symmetrically provided with bottom overflow holes (8) at both ends. The bottom overflow holes (8) are plugged with water-soluble plugs (9) at their inner ends. The lengths of the multiple water-soluble plugs (9) correspond to the thickness of the inner wall of the corresponding biodegradable drug storage chamber (7). The inner end of the biodegradable drug storage chamber (7) is filled with a number of gel liquids (10). The gel liquids (10) flow out through the bottom overflow holes (8). The front and rear inner walls of the biodegradable drug storage chamber (7) are symmetrically provided with side vertical grooves (11).

2. The biodegradable minimally invasive bone screw according to claim 1, characterized in that: The upper inner end of the biodegradable drug storage compartment (7) is slidably connected to a follower inner column plate (12), and the front and rear ends of the follower inner column plate (12) are symmetrically fixedly connected to an extended sliding inner block (13).

3. The biodegradable minimally invasive bone screw according to claim 2, characterized in that: The extended sliding inner block (13) is slidably connected to the side vertical slide groove (11), and the lower outer side of the follower inner column plate (12) is fixedly connected with an outward protruding rubber ring (14).

4. The biodegradable minimally invasive bone screw according to claim 3, characterized in that: The protruding rubber ring (14) is in contact with the inner wall of the biodegradable drug storage chamber (7), and the follow-up inner column plate (12) is located above the gel liquid (10).

5. The biodegradable minimally invasive bone screw according to claim 1, characterized in that: The inner end of the screw body (1) is fixedly connected to a plurality of reinforcing inner columns (4), and the plurality of reinforcing inner columns (4) are arranged in a ring at equal intervals.

6. The biodegradable minimally invasive bone screw according to claim 1, characterized in that: The outer end of the water-soluble plug (9) is fixedly connected with an external anti-detachment texture (15), and the inner sidewall of the bottom overflow hole (8) is fixedly connected with an internal anti-detachment texture (16).

7. The biodegradable minimally invasive bone screw according to claim 6, characterized in that: The water-soluble plug (9) and the bottom overflow hole (8) are connected to each other through the outer anti-detachment texture (15) and the inner anti-detachment texture (16).

Images