A bendable locking intramedullary fixation device

By designing a flexible and locking intramedullary fixation device, the problem of insufficient mechanical strength of straight intramedullary nails in curved bones is solved, enabling flexible movement and stable fixation within curved medullary cavities. This device is suitable for minimally invasive fracture fixation of the pelvis and long bones of the limbs.

CN116509525BActive Publication Date: 2025-11-21SHANDONG WEIGAO ORTHOPEDIC DEVICE COMPANY
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Patent Information

Application Number
CN202310502186.X
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2023-05-06
Publication Date
2025-11-21
Estimated Expiration
2043-05-06

AI Technical Summary

Technical Problem

Existing straight intramedullary nails lack sufficient mechanical strength in curved bones, making it difficult to securely fix them within the medullary cavity of curved bones such as the pelvic bone, and may cause the screws to penetrate the bone and damage soft tissue.

Method used

A flexible and locking intramedullary fixation device was designed, including a screw head, a screw rod, a tailstock, and a flexible cable. Through the combination of a helical section and a locking element, the device can switch between flexible and rigid states, adapt to flexible movement within the curved medullary cavity, and achieve stable fixation after locking.

Benefits of technology

This device can be flexibly inserted into the medullary cavity in a flexible state and provides stable fixation in a rigid state, solving the need for minimally invasive surgery for curved bone fractures, reducing operation time and trauma, and is suitable for the fixation of curved bones in the pelvis and long bones in the limbs.

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Abstract

The application relates to the technical field of medical devices, in particular to a bendable and lockable intramedullary fixation device. The device comprises a nail head, one end of the nail head is provided with a first spiral section, a plurality of counterbores are distributed on the spiral body of the first spiral section; a nail rod, the nail rod is assembled by a plurality of second spiral sections, a plurality of first perforations are distributed on the spiral body of the second spiral section; a tail seat, one end of the tail seat close to the nail rod is provided with a third spiral section, a plurality of second perforations are distributed on the spiral body of the third spiral section, one end of the tail seat away from the nail rod is provided with a mounting hole, the inner diameter of the end of the mounting hole close to the nail rod is smaller than that of the end away from the nail rod, a plurality of adjusting channels are arranged on the inner wall of the mounting hole in the circumferential direction, a locking piece is threadedly connected in the mounting hole of the tail seat; a flexible control line, one end of the flexible control line is fixed in the counterbores, the other end of the flexible control line passes through the cable passage and then passes out of the adjusting channel; the device can be locked after the bending degree is adjusted.
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Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to an intramedullary fixation device with bendable locking. BACKGROUND

[0002] Fractures can occur in straight bones such as femur or curved bones such as pelvic bone. During the fracture surgery, the fracture site needs to be reduced first and then fixed. The fracture fixation method is mainly affected by factors such as fracture type, bone type and patient's health condition. Fracture fixation can be divided into external fixation and internal fixation. External fixation is commonly used in fracture fixation surgery of pelvic bone, which connects the long screw inserted into the ilium with the frame outside the human body to fix the fracture site. Examples of internal fixation mainly include intramedullary nail fixation by intramedullary cavity implantation and nail plate fixation across the fracture site. In the current minimally invasive reduction and fixation surgery, the internal fixation method has more obvious effect.

[0003] The fixation surgery of intramedullary nail by intramedullary cavity implantation is popular in straight bones such as femur and tibia. The strong mechanical structure can well resist bending and shearing force, so that the patient can be discharged in a short time. However, the bending characteristics of curved bones such as pelvic bone limit the mechanical strength of straight intramedullary nails in curved intramedullary cavities, and even the screw may penetrate the bone and injure the soft tissue. Therefore, there is an urgent need for an intramedullary fixation device with bendable characteristics, which can move flexibly in the intramedullary cavity of the curved bone while maintaining good mechanical strength of the intramedullary nail, and achieve stable fixation effect after locking the device. SUMMARY

[0004] The purpose of the present application is to provide an intramedullary fixation device with bendable locking, which overcomes the shortcomings of the prior art, maintains good mechanical strength of the intramedullary nail, moves flexibly in the intramedullary cavity of the curved bone, and achieves stable fixation effect after locking the device.

[0005] The technical solution adopted by the present application to solve its technical problems is:

[0006] An intramedullary fixation device with bendable locking, comprising:

[0007] A nail head, one end of the nail head is provided with a first spiral segment, the first spiral segment has at least two layers of spiral bodies, and there is a certain gap between the adjacent two layers of spiral bodies to facilitate bending deformation of the overall structure within a small angle, and a plurality of counterbores are distributed on the spiral bodies of the first spiral segment;

[0008] A nail rod, the nail rod is assembled by a plurality of second spiral segments, the end surfaces of the adjacent two second spiral segments are in contact, one of the end surfaces of the second spiral segment close to the nail head is in contact with the end surface of the first spiral segment of the nail head, a plurality of first perforations are distributed on the spiral bodies of the second spiral segment, and the second spiral segment also has at least two layers of spiral bodies.

[0009] The tail seat is provided with a third spiral section near the end of the nail rod, the end surface of the third spiral section is in contact with the end surface of the second spiral section near the third spiral section, and a plurality of second perforations are distributed on the spiral body of the third spiral section. The end of the tail seat away from the nail rod is provided with a mounting hole, the inner diameter of the end of the mounting hole near the nail rod is smaller than the inner diameter of the end away from the nail rod, a plurality of adjusting channels are arranged on the inner wall of the mounting hole in the circumferential direction, and the end of the mounting hole away from the nail rod is provided with a thread;

[0010] The locking piece is threadedly connected in the mounting hole of the tail seat;

[0011] The flexible cable, after the assembly of the nail head, the nail rod and the tail seat, the counterbores, the first perforations and the second perforations form a plurality of cable channels, the positions of the cable channels correspond to the positions of the adjusting channels one by one, the number of the flexible cables corresponds to the number of the cable channels, one end of the flexible cable is fixed in the counterbore, and the other end passes through the cable channel and then passes out of the adjusting channel;

[0012] When the locking piece is located at the end of the mounting hole with a larger inner diameter, the first spiral section, the second spiral section and the second spiral section can be finely adjusted in curvature, when the locking piece enters the end of the mounting hole with a smaller inner diameter, the flexible cable is extruded and fixed, and the relative positions of the first spiral section, the second spiral section and the third spiral section are fixed.

[0013] Further, the outer wall of the nail head is provided with a tapered thread and a self-tapping groove, which has the same structure as a conventional self-tapping tapered head screw. When the intramedullary fixation device rotates and advances in the intramedullary channel, the structure of the tapered thread can ensure that the position of the device in the medullary cavity is more stable and firm, avoiding falling off and position misplacement. The nail head is provided with a guide wire through hole in the axial direction, which provides a movable channel for the guide wire and ensures that the intramedullary fixation device will not deviate when pushed along the guide wire path.

[0014] Further, the end of the tail seat away from the nail rod is provided with a hexagonal groove, and the end of the locking block away from the nail rod is also provided with a hexagonal groove.

[0015] Further, the cable channel is provided with 4.

[0016] Further, the end of the locking piece near the nail rod is an arc surface structure, which is more convenient for extruding the flexible cable to realize the locking and fixing of the device, and can also avoid unnecessary damage to the flexible cable.

[0017] The flexible locking intramedullary fixation device of the application, when the flexible cable is in a relaxed state, four flexible cables can slide freely in the cable channel and the adjusting channel along with the bending of the device, when the flexible locking intramedullary fixation device is moved to a suitable position in the medullary cavity, the locking member is placed in the mounting hole of the tail seat. The tail seat and the locking member are respectively equipped with corresponding hexagonal wrenches, and the tail seat is fixed to rotate the locking member by using the antagonistic action of the two, under the meshing action of the internal and external threads between the tail seat and the locking member, the locking member slides to the inside of the mounting hole while rotating, when the locking member moves to the part with smaller inner diameter of the mounting hole, the arc-shaped side wall surface at the front end of the locking member extrudes the flexible cable to complete the locking fixation of the device.

[0018] The application has the following advantages compared with the prior art: the flexible locking intramedullary fixation device of the application is suitable for the fixation of pelvic curved bone and long bone fractures, provides a minimally invasive surgical treatment scheme for curved bone fractures, and can achieve the surgical effect more simply and conveniently compared with the traditional external fixation method for treating pelvic fractures and other curved bones, saves the operation time, and fully plays the advantages of small trauma and rapid recovery of orthopedic minimally invasive surgery. The device can be inserted into the internal medullary cavity and meet the curved path in the flexible state, and can support and fix the tensile and vertical shear stress required by the fractured part in the rigid state. By using the intramedullary fixation device that can be converted between the flexible and rigid states, the mechanical fixation problem existing in the internal fixation operation of the pelvic bone and other curved bones can be minimized or eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the application;

[0020] Figure 2 It is a schematic diagram of the structure of the nail head of the application;

[0021] Figure 3 It is another angle schematic diagram of the structure of the nail head of the application;

[0022] Figure 4 It is a schematic diagram of the structure of the nail head of the application;

[0023] Figure 5 It is a schematic diagram of the structure of the second threaded segment of the application;

[0024] Figure 6 It is a schematic diagram of the structure of the second threaded segment of the application;

[0025] Figure 7 It is a sectional view of the application; Figure 6

[0026] ​Figure 8 Structure diagram of the tail seat of the present application;

[0027] Figure 9 Structure diagram of the tail seat of the present application from another angle;

[0028] Figure 10 Sectional view of the tail seat of the present application;

[0029] Figure 11 Structure diagram of the locking member of the present application;

[0030] Figure 12 Structure diagram of the locking member of the present application in the state of retracted flexible cable;

[0031] Wherein, 1 nail head, 101 first spiral segment, 102 counterbore, 103 tapered thread, 104 self-tapping groove, 105 guide wire through hole, 2 nail rod, 201 second spiral segment, 202 first perforation, 3 tail seat, 301 third spiral segment, 302 second perforation, 303 mounting hole, 304 adjusting channel, 4 locking member, 401 cambered surface structure, 5 flexible cable. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0033] As Figures 1-12 shown in the embodiments, a bendable and lockable intramedullary fixation device comprises:

[0034] A nail head 1, one end of the nail head 1 is provided with a first spiral segment 101, the first spiral segment 101 has at least two layers of spiral bodies, and there is a certain gap between the adjacent two layers of spiral bodies, so as to facilitate the bending deformation of the overall structure within a small angle, and a plurality of counterbores 102 are distributed on the spiral body of the first spiral segment 101.

[0035] A nail rod 2, the nail rod 2 is assembled by a plurality of second spiral segments 201, the end surfaces of the adjacent two second spiral segments 201 are in contact, one of the end surfaces of the second spiral segment 201 close to the nail head 1 is in contact with the end surface of the first spiral segment 101 of the nail head 1, a plurality of first perforations 202 are distributed on the spiral body of the second spiral segment 201, and the second spiral segment 201 also has at least two layers of spiral bodies.

[0036] The tail seat 3 is provided with a third spiral section 301 at one end close to the nail rod 2, the end surface of the third spiral section 301 is in contact with the end surface of the second spiral section 201 close to the third spiral section 301, and a plurality of second through holes 302 are distributed on the spiral body of the third spiral section 301. The end of the tail seat 3 away from the nail rod 2 is provided with a mounting hole 303, the inner diameter of the end of the mounting hole 303 close to the nail rod 2 is smaller than the inner diameter of the end away from the nail rod 2, and a plurality of adjusting channels 304 are arranged on the inner wall of the mounting hole 303 in the circumferential direction. The end of the mounting hole 303 away from the nail rod 2 is provided with a thread 305.

[0037] The locking piece 4 is threadedly connected in the mounting hole 303 of the tail seat 3.

[0038] The flexible cable 5, after the assembly of the nail head 1, the nail rod 2 and the tail seat 3, the counterbore 102, the first through hole 202 and the second through hole 302 form a plurality of cable channels, the positions of the cable channels correspond one by one to the positions of the adjusting channels 304, the number of the flexible cables 5 corresponds to the number of the cable channels, one end of the flexible cable 5 is fixed in the counterbore 102, and the other end passes through the cable channel and then passes out of the adjusting channel 304.

[0039] When the locking piece 4 is located at the end of the mounting hole 303 with a larger inner diameter, the first spiral section 101, the second spiral section 201 and the second spiral section 201 can be finely adjusted in curvature, when the locking piece 4 enters the end of the mounting hole 303 with a smaller inner diameter, the flexible cable 5 is squeezed and fixed, and the relative positions of the first spiral section 101, the second spiral section 201 and the third spiral section 301 are fixed.

[0040] In the embodiment, the outer wall of the nail head 1 is provided with a tapered thread 103 and a self-tapping groove 104, which have the same structure as a conventional self-tapping tapered head screw. When the intramedullary fixation device is rotated and pushed in the intramedullary channel, the structure of the tapered thread 103 can ensure that the position of the device in the marrow cavity is more stable and firm, and can avoid falling off and position misplacement. The nail head 1 is provided with a guide wire through hole 105 along the axial direction, which provides a movable channel for the guide wire and ensures that the intramedullary fixation device will not deviate when pushed along the guide wire path.

[0041] In the embodiment, the end of the tail seat 3 away from the nail rod 2 is provided with a hexagonal groove, and the end of the locking block away from the nail rod 2 is also provided with a hexagonal groove.

[0042] In the embodiment, the cable channel is provided with 4.

[0043] In the embodiment, the end of the locking piece 4 close to the nail rod 2 is an arc surface structure 401, which is more convenient for squeezing the flexible cable 5 to realize the locking and fixing of the device, and can also avoid unnecessary damage to the flexible cable 5.

[0044] In the flexible relaxed state of the intramedullary fixation device, there are small gaps between each of the first, second and third threaded segments of the intermediate section of the device and between each other, which can be freely bent within a certain angle range by stretching and bending the gaps; when the angle position of the intramedullary fixation device is adjusted, the locking member 4 of the adjusting tail seat 3 is adjusted to achieve the locking and fixation of the device; in use, after the fracture is reduced, a guide wire is used to pass through the fracture position in the medullary cavity of the curved bone, and an intramedullary channel is established along the guide wire path, and finally the intramedullary fixation device is pushed into the intramedullary channel along the guide wire path to reach the appropriate position and be locked and fixed.

[0045] The above specific embodiments are only specific cases of the present application, and the patent protection scope of the present application includes but is not limited to the product forms and styles of the above specific embodiments, and any appropriate changes or modifications made by any person skilled in the art to the present application in accordance with the claims of the present application shall fall within the patent protection scope of the present application.

Claims

1. A flexible, locking intramedullary fixation device, characterized in that, The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail.

2. The bendable, lockable intramedullary fixation device of claim 1, wherein: The application relates to a flexible control line for a flexible nail.

3. The flexible locking intramedullary fixation device of claim 1, wherein: The application relates to a flexible control line for a flexible nail.

4. The flexible locking intramedullary fixation device of claim 1, wherein: The application relates to a flexible control line for a flexible nail.

5. The flexible locking intramedullary fixation device of claim 1, wherein: The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. The application relates to a flexible control line for a flexible nail. 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Citation Information

Patent Citations

  • Intramedullary fixing device capable of being locked in bending mode

    CN220477643U