A new adjustable intramedullary nail

Abstract

This invention discloses a novel adjustable intramedullary nail, comprising a hollow main nail, a proximal end of the nail, and a main body of the nail, which are integrally formed. The diameter of the proximal end of the nail is larger than that of the main body. Multiple through-holes for dynamic screws are provided at the proximal end of the nail. An adjustment hole is provided on the main body of the nail, away from the proximal end. A dynamic bone screw is installed in each of the dynamic screw holes and can move axially along the holes. A tail cap is installed on the proximal side of the nail, and an elastomer is placed between the tail cap and the dynamic bone screw. An absorbable washer is placed distal to the dynamic bone screw to support it. An adjustment device for adjusting the stress at the fracture ends is provided on the main body of the nail, which can adjust the stress at the fracture ends according to the specific fracture conditions, avoid stress shielding at the fracture ends, accelerate fracture healing, reduce delayed healing and nonunion, and decrease the incidence of refracture after removal of the intramedullary nail.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medical devices, and particularly relates to a novel adjustable intramedullary nail. BACKGROUND

[0002] The method of internal fixation of bone plate and intramedullary nail has been used in clinic for many years, and there are various methods for the fixation of fracture, among which the intramedullary nail fixation is one of the most commonly used methods. The traditional intramedullary nail is fixed on the fractured bone through a screw, so that the intramedullary nail is integrated with the bone. However, in the later stage of fracture repair, due to the stress shielding effect of the intramedullary nail, the fractured end cannot be given appropriate stress stimulation, which is prone to delayed healing, non-union, slow mineralization of the bone, long internal fixation time, re-fracture after removal of the intramedullary nail and other disadvantages, which limits its popularization and application. Especially for some special types of skeletal fractures in clinic, the intramedullary nail body needs to be thin in diameter, and the distal end cannot be locked by a locking bone screw, but can only be locked on one side, which cannot firmly fix the fractured bone, and is prone to reduction loss, fracture displacement, delayed healing and non-union of the fractured end. Therefore, it is an urgent problem to design an intramedullary nail which can adjust the stress of the fractured end according to the healing condition of the fracture, avoid stress shielding, and lock the distal end. SUMMARY

[0003] The purpose of the present application is to provide a novel adjustable intramedullary nail to solve the problems of the use of normal intramedullary nail, i.e. the nail body is too large in diameter, especially the distal end cannot be locked by a bone screw, but can only be locked on one side, which cannot firmly fix the fractured bone, and is prone to reduction loss, fracture displacement, delayed healing and non-union of the fractured end.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A novel adjustable intramedullary nail, comprising an intramedullary nail main nail, the intramedullary nail main nail being a hollow structure, the intramedullary nail main nail comprising an intramedullary nail proximal end and an intramedullary nail main body, the intramedullary nail proximal end and the intramedullary nail main body being an integral structure, the diameter of the intramedullary nail proximal end being larger than that of the intramedullary nail main body, a through power screw hole being arranged at the intramedullary nail proximal end, an adjusting hole being arranged at the distal side of the intramedullary nail main body away from the intramedullary nail proximal end, a power bone screw being installed in the power screw hole, the power bone screw being able to move axially along the power screw hole, a tail cap being installed on the intramedullary nail proximal end side, an elastic body one being arranged between the tail cap and the power bone screw, an absorbable gasket being arranged at the distal side of the power bone screw, the absorbable gasket supporting the power bone screw, and an adjusting device for adjusting the stress of the fractured end being arranged on the intramedullary nail main body.

[0006] Further, the adjusting device comprises an adjusting member installed in the intramedullary nail body cavity, the adjusting member comprises a bulging part and a body part, which can be integrated or separated, the bulging part is located at the transition of the proximal end of the intramedullary nail and the body of the intramedullary nail, the outer diameter of the bulging part is larger than the inner diameter of the intramedullary nail body cavity, and the other end of the body part of the adjusting member is provided with a fixed clamp after passing through the adjusting hole, which can be fastened and fixed with the body part of the adjusting member.

[0007] Further, the installation form of the tail cap is one of the following: a, the inner wall of the proximal end of the intramedullary nail is provided with internal threads, the tail cap is provided with external threads matched with the internal threads, and the tail cap is threadedly connected with the proximal end of the intramedullary nail; b, an annular groove and a vertical guide groove communicated with the annular groove are arranged along the inner wall of the proximal end of the intramedullary nail, and the head end of the tail cap is provided with a protrusion which can slide along the annular groove and the vertical guide groove; c, an expansion sleeve is arranged at the head of the tail cap.

[0008] Further, the elastic body is one of a pressure regulating spring and an elastic balloon, when the elastic body is the pressure regulating spring, the installation form of the pressure regulating spring is one of the following: a, the pressure regulating spring is installed in the accommodating cavity formed in the tail cap, the dynamic bone screw and the inner wall of the proximal end of the intramedullary nail; b, a guide sleeve is arranged on the outer side of the proximal end of the intramedullary nail, the guide sleeve is provided with a through hole corresponding to the dynamic screw hole, and the pressure regulating spring is sleeved on the outer side of the proximal end of the intramedullary nail and the tail cap, one end of the pressure regulating spring abuts against the guide sleeve, and the other end of the pressure regulating spring abuts against the eave of the tail cap; when the elastic body is the elastic balloon, the elastic balloon is located in the accommodating cavity formed in the tail cap, the dynamic bone screw and the inner wall of the proximal end of the intramedullary nail, and the distal side of the elastic balloon is provided with a balloon base.

[0009] Further, when the dynamic screw hole is provided with two through holes in the upper and lower directions, the guide sleeve is sleeved on the proximal end of the intramedullary nail, and can be provided in a half-sleeved or full-sleeved form, when the guide sleeve is half-sleeved, the guide sleeve is located above the lower dynamic screw hole, and the guide sleeve is provided with a through hole corresponding to the upper dynamic screw hole; when the guide sleeve is full-sleeved, the guide sleeve is respectively provided with through holes corresponding to the upper dynamic screw hole and the lower dynamic screw hole.

[0010] Further, the installation form of the absorbable gasket is one of the following: a, the inner wall of the proximal end of the intramedullary nail is provided with a boss, and the boss is provided with the absorbable gasket; b, the inner wall of the proximal end of the intramedullary nail is provided with internal threads II, the outer wall of the absorbable gasket is provided with external threads II, and the absorbable gasket is threadedly connected with the inner wall of the proximal end of the intramedullary nail.

[0011] Further, the adjusting member is sleeved with a pressure regulating spring II, and the pressure regulating spring II is located between the bulging part and the transition.

[0012] Further, an upper magnetic body is fixedly arranged in the tail cap, and the tail cap can be driven to move up and down along the proximal end of the intramedullary nail under the action of an external magnetic field.

[0013] Further, the adjusting hole is arranged on the top end and the side wall of the intramedullary nail body, and is an inclined hole or a horizontal hole.

[0014] Further, a through fixing screw hole is arranged below the proximal end of the intramedullary nail and the power screw hole, and a fixing bone screw is arranged in the fixing screw hole.

[0015] Further, the adjusting member body is one of a metal cable, a rope, a metal rod and a metal wire; and the intramedullary nail body is arranged to have a curvature suitable for a human bone.

[0016] The present application has the advantages of easy fixation, convenient operation, simple structure, wide application range, and solves the problems of conventional intramedullary nail body with large diameter, which cannot be used for bones with small diameter; or the intramedullary nail body with small diameter, but the distal end of the intramedullary nail cannot be locked by a bone screw, and only the proximal end can be locked, which causes the fracture bone to be not firmly fixed, and the problems of easy reduction loss, fracture displacement, delayed healing and non-healing of the fracture end, and the like are avoided; the absorbable gasket and the elastic body one and the pressure regulating spring two are used to adjust the stress of the fracture end and stimulate the body tissue to form new bone, avoid the stress shielding of the fracture end, accelerate the fracture healing, and shorten the fixation time of the intramedullary nail. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Figure 1 FIG. 1 is a structural schematic diagram of an embodiment of the present application;

[0018] Figure 2 FIG. 2 is a structural schematic diagram of the intramedullary nail body in an embodiment of the present application;

[0019] Figure 3 FIG. 3 is a structural schematic diagram of an embodiment of the present application; Figure 2 FIG. 4 is an enlarged view of A in FIG. 3;

[0020] Figure 4 FIG. 5 is a structural schematic diagram of an embodiment of the present application;

[0021] Figure 5 FIG. 6 is a structural schematic diagram of an embodiment of the present application;

[0022] Figure 6 FIG. 7 is a structural schematic diagram of an embodiment of the present application;

[0023] Figure 7 FIG. 8 is a structural schematic diagram of an embodiment of the present application;

[0024] Figure 8 FIG. 9 is a structural schematic diagram of an embodiment of the present application;

[0025] Figure 9 FIG. 10 is a structural schematic diagram of an embodiment of the present application;

[0026] Figure 10This is a schematic diagram of the structure of Embodiment 8 of the present invention;

[0027] Figure 11 This is a schematic diagram of the structure of Embodiment Nine of the present invention;

[0028] Figure 12 This is a schematic diagram of the structure of Embodiment 10 of the present invention;

[0029] Figure 13 This is a schematic diagram of the structure of Embodiment Eleven of the present invention;

[0030] In the diagram: 1-Intramedullary nail body, 2-Tail cap, 3-Proximal end of intramedullary nail, 4-Upper dynamic screw hole, 5-Upper dynamic bone screw, 6-Adjustment hole, 7-Pressure adjustment spring one, 8-Upper magnetic body, 9-Absorbable washer, 10-Protrusion, 11-Annular groove, 12-Vertical guide groove, 13-Lower dynamic screw hole, 14-Lower dynamic bone screw, 15-Expansion part, 16-Body part, 17-Fixture clip, 18-Pressure adjustment spring two, 19-Elastic balloon, 20-Semi-guide sleeve, 21-Full guide sleeve, 22-Expansion sleeve, 23-Boss, 24-Fixture screw hole, 25-Fixture bone screw, 26-Nut, 27-Lower magnetic body. Detailed Implementation

[0031] To make the technical means, creative features, objectives, and effects of this invention readily understandable, the invention is further described below in conjunction with specific illustrations. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral connection, or a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.

[0032] Example 1, as Figure 1 As shown, a novel adjustable intramedullary nail includes a main intramedullary nail with a hollow structure. The main nail comprises a proximal end 3 and a main body 1, which are integrally formed. The diameter of the proximal end 3 is larger than the diameter of the main body 1. Two through-holes for power screws are provided at the proximal end 3: an upper power screw hole 4 and a lower power screw hole 13. Upper power bone screws 5 and lower power bone screws 14 are respectively installed in these holes and can move up and down along them. An adjustment hole 6 is provided at the distal end of the main body 1, away from the proximal end 3. A tail cap 2 is installed on the side of the proximal end 3.

[0033] The inner wall of the proximal end 3 of the intramedullary nail has an internal thread, and the tail cap 2 has an external thread that matches the internal thread. The tail cap 2 is threadedly connected to the proximal end 3 of the intramedullary nail. A pressure adjusting spring 7 is provided between the tail cap 2 and the upper dynamic bone screw 5, that is, the pressure adjusting spring 7 is installed in the cavity formed by the inner walls of the tail cap 2, the upper dynamic bone screw 5, and the proximal end 3 of the intramedullary nail. An absorbable washer 9 is provided below the upper dynamic bone screw 7. The absorbable washer 9 supports the upper dynamic bone screw 7. The inner wall of the proximal end 3 of the intramedullary nail has an internal thread, and the outer side of the absorbable washer 9 has an external thread. The absorbable washer 9 is threadedly connected to the inner wall of the proximal end 3 of the intramedullary nail. An adjustment device is provided on the main body 1 of the intramedullary nail, and the adjustment device includes an adjustment component installed in the cavity of the main body of the intramedullary nail.

[0034] The adjusting component includes an enlarged portion 15 and a body portion 16. The enlarged portion 15 and the body portion 16 can be integral or separate. In this embodiment, they are integral structures. The enlarged portion 15 is located at the transition between the proximal end 3 of the intramedullary nail and the main body 1 of the intramedullary nail. The outer diameter of the enlarged portion 15 is larger than the inner diameter of the cavity of the main body 1 of the intramedullary nail. One end of the body portion 16 is connected to the enlarged portion 15, and the other end passes through the adjusting hole 6 and is fitted with a fixing clip 17. The adjusting hole 6 is located on the top or side wall of the main body 1 of the intramedullary nail and can be configured as a horizontal hole or an oblique hole. In this embodiment, the adjusting hole 6 is located on the side wall of the main body 1 of the intramedullary nail and is configured as an oblique hole. The body portion 16 can be one of a metal cable, rope, metal rod, or metal wire. In this embodiment, a metal cable is selected.

[0035] When using a novel adjustable intramedullary nail to fix bone, the nail is inserted into the fracture shaft of the human body according to the standard operating procedure. The adjustment component is implanted into the main body 1 of the intramedullary nail, the body 16 is tightened, the distal bone is pushed to reduce and compress the fracture ends, and then the fixation clip 17 is tightly fixed to the body 16 against the bone. The absorbable washer 9 is screwed in, and the upper dynamic bone screw 5 and the lower dynamic bone screw 14 are installed in the upper dynamic screw hole 4 and the lower dynamic screw hole 13 of the proximal end 3 of the intramedullary nail, respectively. Then, the pressure adjusting spring 7 is implanted in the proximal end 3 of the intramedullary nail.

[0036] Screw in the tail cap 2, applying downward axial stress to the adjusting spring 7, which in turn applies downward axial stress to the upper dynamic bone screw 5. After the device has been implanted in the human body for a period of time, the absorbable washer 9 is absorbed and no longer applies upward axial stress to the upper dynamic bone screw 5. The bone fixed to the proximal end 3 of the intramedullary nail is subjected to downward axial stress from the adjusting spring 7, which in turn applies a reverse axial force proximal to the upper dynamic bone screw 5, the adjusting spring 7, the tail cap 2, the proximal end 3 of the intramedullary nail, and the fixation clamp 17 at the distal end of the intramedullary nail body 1. This applies axial stress to the distal bone and fracture ends, ensuring that physiological stress stimulation and transmission are always present during the fracture healing process, promoting fracture healing. The elastic force of the adjusting spring 7 can be determined by controlling the depth of screwing in the tail cap 2.

[0037] Example 2, as Figure 2 , Figure 3 , Figure 4 As shown, the difference between this embodiment and embodiment 1 lies in the connection method between the tail cap 2 and the proximal end 3 of the intramedullary nail. In this embodiment, an annular groove 11 and a vertical guide groove 12 communicating with the annular groove 11 are provided along the inner wall of the proximal end 3 of the intramedullary nail. The tail cap 2 is provided with a protrusion 10, which can slide up and down along the vertical guide groove 12 and can rotate along the annular groove 11.

[0038] Example 3, as Figure 5 As shown, the difference between this embodiment and embodiment 1 is that the pressure regulating spring 7 is replaced with an elastic balloon 19, and a balloon base is provided below the elastic balloon 19.

[0039] Example 4, as Figure 6 As shown, the difference between this embodiment and embodiment 1 lies in the connection method between the tail cap 2 and the proximal end 3 of the intramedullary nail. In this embodiment, an expansion sleeve 22 is provided at the head of the tail cap 2. The tail cap 2 and the expansion sleeve 22 are threaded together. The distal arm of the expansion sleeve 22 is thickened and the side wall is provided with a slot, dividing the side wall into more than 3 parts. By screwing in the tail cap 2, the lower side wall of the expansion sleeve 22 can be fixed to the inner wall of the proximal end 3 of the intramedullary nail.

[0040] Example 5, as Figure 7 As shown, the difference between this embodiment and embodiment 1 lies in the installation form of spring 7. A semi-guide sleeve 20 is provided on the outer side of the proximal end 3 of the intramedullary nail. The semi-guide sleeve 20 is provided with a through hole corresponding to the upper power screw hole 4. The pressure adjusting spring 7 is fitted on the outer side of the proximal end 3 of the intramedullary nail and the tail cap 2. One end of the spring abuts against the semi-guide sleeve 20, and the other end abuts against the eaves of the tail cap 2. The semi-guide sleeve 20 can also be provided on the inner side of the proximal end 3 of the intramedullary nail.

[0041] Example 6, as Figure 8 As shown, the difference between this embodiment and Embodiment 5 is that the guide sleeve is configured as a full guide sleeve 21. When it is a full guide sleeve 21, the full guide sleeve 21 is provided with through holes corresponding to the upper power screw hole 4 and the lower power screw hole 13, respectively. The full guide sleeve 21 can also be located on the inner side of the proximal end 3 of the intramedullary nail.

[0042] Example 7, as Figure 9 As shown, the difference between this embodiment and embodiment 1 lies in the installation method of the absorbable washer 9. In this embodiment, a boss 23 is provided on the inner wall of the proximal end 3 of the intramedullary nail, and an absorbable washer 9 is provided on the boss 23.

[0043] Example 8, as Figure 10 As shown, the difference between this embodiment and Embodiment 1 is that a second spring 18 is fitted onto the adjusting member 16, and the second spring 18 is located between the enlarged portion 15 and the transition portion. The adjusting hole 6 is located on the top of the intramedullary nail body 1.

[0044] Example 9, as Figure 11 As shown, the difference between this embodiment and Embodiment 1 is that an upper magnetic body 8 is fixedly installed inside the tail cap 2, which can drive the tail cap 2 to move up and down along the proximal end 3 of the intramedullary nail under the action of an external magnetic field. The adjustment hole 6 is located at the top of the proximal end 3 of the intramedullary nail.

[0045] Example 10, as Figure 12 As shown, the difference between this embodiment and Embodiment 1 is that a through-hole fixation screw hole 24 is provided at the proximal end of the intramedullary nail, below the dynamic screw hole, and a fixation bone screw 25 is installed in the fixation screw hole 24. Figure 13 As shown, a nut 26 can also be provided above the enlarged portion 15, and the nut 26 is threadedly connected to the intramedullary nail body 1.

[0046] Example 11, as Figure 13 As shown, the difference between this embodiment and Embodiment 1 is that a lower magnetic body 27 is provided above the enlarged portion 15, and the lower magnetic body 27 can push the body portion 16 downward under the action of an external magnetic field.

[0047] In the above embodiments, the intramedullary nail master screw is configured with a curvature that is compatible with human bone.

[0048] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A new adjustable intramedullary nail comprising an intramedullary nail main pin, characterized in that: The intramedullary nail main nail is a hollow structure, the intramedullary nail main nail includes intramedullary nail proximal end, intramedullary nail main body, the intramedullary nail proximal end, intramedullary nail main body are integrated structure, the diameter of the intramedullary nail proximal end is greater than the diameter of intramedullary nail main body, the dynamic screw hole is set at the intramedullary nail proximal end, the adjusting hole is set at the intramedullary nail main body far side away from intramedullary nail proximal end, the dynamic bone screw is installed in the dynamic screw hole, the dynamic bone screw can move along the dynamic screw hole axial direction, the tail cap is installed at the intramedullary nail proximal end side, the elastic body one is set between the tail cap and dynamic bone screw, the absorbable washer is set below the dynamic bone screw, the absorbable washer supports the dynamic bone screw, the tail cap gives the dynamic bone screw downward axial stress through the elastic body one, the absorbable washer is absorbed and gradually removes the support to the dynamic bone screw, the upper magnetic body is fixedly set in the tail cap, can drive the tail cap along the intramedullary nail proximal end up and down under the action of external magnetic field, the adjusting device is set on the intramedullary nail main body and is used for adjusting the stress of fracture end; The adjusting device includes the adjusting member installed in the intramedullary nail main body cavity, the adjusting member includes the enlarged part and the body, the enlarged part and the body can be integrated or in split shape, the enlarged part is located at the transition of the intramedullary nail proximal end and the intramedullary nail main body, the outer diameter of the enlarged part is greater than the inner diameter of the intramedullary nail main body cavity, the other end of the body of the adjusting member is set out of the adjusting hole and is provided with the fixed clamp, which can be tightly fixed with the body of the adjusting member; The lower magnetic body is set above the enlarged part, and the lower magnetic body can drive the body of the adjusting member to move downward under the action of the external magnetic field; The mounting form of the absorbable washer is one of the following modes: a, the inner wall of the intramedullary nail proximal end is provided with a boss, and the absorbable washer is arranged on the boss; b, the inner wall of the intramedullary nail proximal end is provided with internal threads two, and the outer wall of the absorbable washer is provided with external threads two, and the absorbable washer is threadedly connected with the inner wall of the intramedullary nail proximal end; The pressure regulating spring two is sleeved on the adjusting member, and the pressure regulating spring two is located between the enlarged part and the transition; The elastic body one is the pressure regulating spring one, the guide sleeve is arranged on the outer side of the intramedullary nail proximal end, the through hole corresponding to the dynamic screw hole is arranged on the guide sleeve, the pressure regulating spring one is sleeved on the outer side of the intramedullary nail proximal end and the tail cap, one end of the pressure regulating spring one abuts against the guide sleeve, and the other end of the pressure regulating spring one abuts against the eaves below the tail cap, and the tail cap gives the dynamic bone screw downward axial stress through the pressure regulating spring one.

2. The new adjustable intramedullary nail according to claim 1, characterized in that: The mounting form of the tail cap is one of the following modes: a. the inner wall of the intramedullary nail proximal end is provided with internal threads, and the tail cap is provided with external threads matched with the internal threads, and the tail cap is threadedly connected with the intramedullary nail proximal end; b. the annular groove and the vertical guide groove communicated with the annular groove are arranged along the inner wall of the intramedullary nail proximal end, the head end of the tail cap is provided with a protrusion, and the protrusion can slide along the annular groove and the vertical guide groove; c. the expansion sleeve is arranged on the head of the tail cap.

3. The new adjustable intramedullary nail according to claim 1, characterized in that: When the power screw hole is arranged as two through holes, the guide sleeve is sleeved on the proximal end of the intramedullary nail and can be arranged as a half sleeve or a full sleeve, when being the half sleeve, the guide sleeve is located above the lower power screw hole, and a through hole corresponding to the upper power screw hole is arranged on the guide sleeve; when being the full sleeve, through holes corresponding to the upper power screw hole and the lower power screw hole are respectively arranged on the guide sleeve.

4. The new adjustable intramedullary nail according to claim 1, characterized in that: The adjusting hole is arranged on the top end and the side wall of the main body of the intramedullary nail, and is a inclined hole or a horizontal hole.

5. The new adjustable intramedullary nail according to claim 4, characterized in that: A through fixed screw hole is arranged below the proximal end of the intramedullary nail and the lower power screw hole, and a fixed bone screw is arranged in the fixed screw hole.

6. The new adjustable intramedullary nail according to claim 5, characterized in that: The body of the adjusting member is one of a metal cable, a rope, a metal rod and a metal wire; and the main nail of the intramedullary nail is arranged to be suitable for the curvature of the human skeleton.

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