Nail unscrewing device for screw-plug-free nail rod system

Abstract

The invention relates to a screw unscrewing device for a screw-plug-free screw-rod system. The screw unscrewing device comprises an outer sleeve; the plugging head is positioned at the tail end of the outer sleeve; the plugging head is configured to at least have an opening state and a tightening state, so that the plugging head can be clamped into a clamping groove of a U-shaped clamping seat of the screw-plug-free nail rod system; and the transmission assembly is configured to be capable of controlling the plugging head to be switched between an opening state and a tightening state so as to control the plugging head to pull the U-shaped clamping seat out of a screw seat of the screw-plug-free screw rod system.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically to orthopedic spinal surgery instruments, and particularly relates to a screw releaser for a screwless rod system. Background Technology

[0002] In posterior spinal pedicle screw fixation systems, such as Figure 1 As shown, a typical screwless rod-and-screw system (1) includes: a screw rod (11) implanted into the vertebral body, a screw seat (12) integrated with the screw rod, and a U-shaped retainer (14) for accommodating the connecting rod (13). During surgery, the connecting rod (13) is inserted into the U-shaped groove (141) of the U-shaped retainer (14), and then the U-shaped retainer (14) is pressed down by a tool (such as a rod presser) to create a strong press-fit interference with the screw seat (12), thereby firmly locking the connecting rod. However, when revision surgery is required (e.g., due to infection, loosening, rod breakage, etc.) or the position of the connecting rod needs to be adjusted during surgery, how to safely separate the connecting rod that is press-fitted and locked in the U-shaped retainer becomes a key technical challenge. Existing technology lacks dedicated tools, leading to the following problems: (a) Difficult to operate, the U-shaped clamp is deeply embedded inside the nail seat, the surrounding operating space is very small, and conventional instruments cannot effectively clamp or apply force; (ii) The risk is extremely high. If tools such as bone chisels and pliers are used to forcefully pry, it is very easy to cause: metal fragments (scratching the surface of the pin seat or U-shaped chuck, producing harmful metal fragments), instrument damage (damaging the precision structure on the U-shaped chuck, making it unusable or affecting removal), tissue damage (slipping of the tool may damage important surrounding nerve and blood vessel tissues) and loosening of the bone interface (improper stress applied may be transmitted to the bone-screw interface, causing the screw to loosen).

[0003] Therefore, there is an urgent need for a specialized device that can reliably connect to a U-shaped retainer and provide a controllable pulling force along the axial direction, thereby smoothly and safely "decompressing" and removing the rod from its holder. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a nail remover for a screwless nail bar system to at least solve one of the above problems.

[0005] This invention provides a staple remover for a screwless staple bar system, comprising: Outer tube; A plug-in head is located at the end of the outer sleeve; the plug-in head is configured to have at least an open state and a closed state, so that the plug-in head can be engaged into the slot of the U-shaped retainer of the screwless plug rod system; The transmission assembly is configured to control the insertion head to switch between an open state and a closed state in order to control the insertion head to pull the U-shaped retainer out of the retainer of the screwless plug rod system.

[0006] Furthermore, the outer sleeve is provided with an inner channel and a rotating window communicating with the inner channel; The end of the inner channel is open; The rotating window is located on the upper part of the side wall of the outer sleeve.

[0007] Furthermore, the transmission assembly includes a rotating handle, a transmission rod, a core rod, and a sleeve; One end of the rotating handle is located in the inner channel and is rotatably connected to the outer tube, while the other end of the rotating handle passes through the rotating window and is located outside the outer tube; The transmission rod is located between the rotating handle and the core rod, and both ends of the transmission rod are rotatably connected to the rotating handle and the core rod, respectively. Most of the core rod is located within the inner channel, and the end portion of the core rod protrudes from the open opening of the inner channel and abuts against the plug head. The core rod is configured to move within the inner channel as the rotating handle is rotated. The sleeve is fitted over the outside of the insertion head and connected to the core rod. The sleeve is configured to move synchronously with the core rod.

[0008] Furthermore, the transmission component includes at least three states, namely a first state, a second state, and a third state; When the transmission assembly is in the first state, the rotation angle of the rotating handle is α, and the plug-in head is in the open state, ready to connect the plug-in head to the U-shaped card seat; When the transmission assembly is in the second state, the rotation angle of the rotating handle is β, and the insertion head is in the tightened state so that the insertion head can clamp and hold the U-shaped card. When the transmission assembly is in the third state, the rotation angle of the rotating handle is γ, and the insertion head is in the tightened state so as to just pull the U-shaped card seat out of the nail seat. Where α > β > γ; the process of rotating the handle from angle β to γ ​​is a process of gradually applying an axial upward force to the U-shaped card holder and an axial downward force to the nail holder, until the U-shaped card holder is pulled out of the nail holder.

[0009] Furthermore, the rotating handle includes a rotating part, a transition part, and a handle part connected in sequence, with the handle part located below the rotating part, and the two ends of the transition part being connected to the end of the rotating part and the beginning of the handle part, respectively; The transition portion is configured such that the handle portion always has a gap with the outer tube; The first end of the rotating part is rotatably connected to the outer sleeve, and the last end of the rotating part is rotatably connected to the first end of the transmission rod; The outer wall of the handle is provided with an anti-slip part; The connection between the rotating handle and the transmission rod is provided with a sector-shaped groove, which provides space for the rotation of the transmission rod.

[0010] Furthermore, the core rod is provided with two control grooves with openings facing away from each other. Each control groove includes at least a straight groove wall and an inclined groove wall. The straight groove wall is vertically arranged. One end of the inclined groove wall is connected to the end of the straight groove wall, and the other end of the inclined groove wall extends downward and outward. The insertion / removal rod is provided with a latch that cooperates with the control groove, and the latch abuts against the control groove; When the latch abuts against the straight groove wall, the insertion head is in a tightened state; When the latch abuts against the inclined groove wall, the insertion head is in an unfolded rotating state.

[0011] Furthermore, the sleeve is fitted onto the end portion of the core rod and the outside of the insertion head, and the shape of the sleeve is adapted to both the insertion head and the core rod; The inner wall of the sleeve is provided with a sliding groove that is adapted to the plug-in head. The sliding groove extends from below the connection between the sleeve and the core rod to the end of the sleeve. The plug-in head extends or retracts from the end of the sleeve through the sliding groove to realize the switching of the plug-in head state. The end of the sleeve is provided with a groove that mates with the connecting rod of the screwless plug rod system. When the transmission component is in the first state and the second state, the groove is located directly above the connecting rod. When the transmission component is in the third state, the connecting rod is embedded in the groove.

[0012] Furthermore, the inner channel is provided with a rotating section, a limiting section and a sliding section from top to bottom, and the diameter of the transmission section is greater than the diameter of the limiting section and the diameter of the sliding section. The rotating window is located in the rotating section, and the assembly parts of the rotating handle, transmission rod, and core rod are located in the rotating section. The diameter of the rotating section matches the diameter of the assembly part, and the diameter of the sliding section matches the diameter of the main rod part of the core rod.

[0013] Furthermore, the limiting segment is provided with an elastic element; The elastic element is sleeved on the first end portion of the main rod and is limited between the assembly portion and the bottom of the limiting section; The elastic element is configured to provide an upward thrust for the outward rotation of the rotary handle, so that the rotary handle can be quickly and accurately rotated to the rotation angle α.

[0014] Furthermore, the plug-in head includes a connecting sleeve and two plug-in rods disposed opposite to each other; The first end of the connecting sleeve is connected to the end of the outer sleeve, and the end of the connecting sleeve is connected to two plug-in rods; Two insertion rods clamp the core rod in the middle, and the insertion rods are located in the sliding groove of the sleeve, and the insertion rods are slidably connected to the sliding groove; The connecting sleeve is located above the connecting pin, and the plane containing the two insertion rods is perpendicular to the connecting pin; The insertion / extraction rod is provided with a latch that mates with the control groove of the core rod, and the latch abuts against the control groove; The bottom of the insertion rod is provided with a hook that cooperates with the slot, so that the insertion rod can clamp the U-shaped card seat.

[0015] Compared with the prior art, at least one of the beneficial effects of the present invention is that the state of the insertion and extraction head can be adjusted by the transmission component, thereby controlling the insertion and extraction head to pull the U-shaped holder out of the nail holder of the screwless rod system, realizing the release of the connecting rod, and providing a safe and efficient solution for revision or adjustment surgery.

[0016] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0018] Figure 1 (a) is a schematic diagram of the structure of the screwless plug rod system in the background art (I); Figure 1 (b) is a schematic diagram of the structure of the screwless plug rod system in the background art (II); Figure 1 (c) is a cross-sectional view of a screwless plug rod system in the background art; Figure 2 (a) is a schematic diagram of the nail remover in a specific embodiment (I); Figure 2 (b) is a schematic diagram of the nail remover in a specific implementation (II); Figure 2 (c) is a cross-sectional view (a) of the pin remover in a specific embodiment; Figure 2(d) is a cross-sectional view (ii) of the pin remover in a specific embodiment; Figure 3 (a) is a cross-sectional view of the transmission assembly of the nail remover in the first state in a specific embodiment; Figure 3 (b) is a partially enlarged cross-sectional view of the transmission assembly of the nail remover in the first state in the specific embodiment; Figure 4 (a) is a schematic diagram of the transmission assembly of the nail remover in the second state in a specific embodiment; Figure 4 (b) is a partially enlarged view of the structural schematic diagram of the transmission assembly of the nail remover in the second state in the specific embodiment; Figure 4 (c) is a cross-sectional view of the transmission assembly of the nail remover in the second state in a specific embodiment; Figure 4 (d) is a partially enlarged cross-sectional view of the transmission assembly of the nail remover in the second state in the specific embodiment; Figure 5 (a) is a schematic diagram of the transmission assembly of the nail remover in the third state in a specific embodiment; Figure 5 (b) is a partially enlarged view of the structural schematic diagram of the transmission assembly of the nail remover in the third state in the specific embodiment; Figure 5 (c) is a cross-sectional view of the drive assembly of the nail remover in the third state in the specific embodiment; Figure 5 (d) is a partially enlarged cross-sectional view of the transmission assembly of the nail remover in the third state in the specific embodiment; Figure 6 (a) is a schematic diagram of the outer sleeve in a specific embodiment (I); Figure 6 (b) is a schematic diagram of the outer sleeve in a specific embodiment (II); Figure 6 (c) is a cross-sectional view of the outer sleeve in a specific embodiment; Figure 7 (a) is a schematic diagram of the transmission assembly in a specific embodiment; Figure 7 (b) is a schematic diagram of the transmission assembly in a specific implementation embodiment; Figure 8 (a) is a schematic diagram of the rotating handle in a specific embodiment (I); Figure 8 (b) is a schematic diagram of the rotating handle in a specific embodiment (II); Figure 8(c) is a cross-sectional view of the rotating handle in the specific embodiment; Figure 9 (a) is a schematic diagram of the core rod in a specific embodiment (I); Figure 9 (b) is a schematic diagram of the core rod in a specific implementation (II); Figure 9 (c) is a partially enlarged view (a) of the structural schematic diagram of the core rod in the specific embodiment; Figure 9 (d) is a partial enlarged view (II) of the structural schematic diagram of the core rod in the specific implementation embodiment; Figure 10 (a) is a schematic diagram of the sleeve structure in a specific embodiment (I); Figure 10 (b) is a schematic diagram of the sleeve structure in a specific embodiment (II); Figure 10 (c) is a cross-sectional view of the sleeve in the specific embodiment; Figure 11 (a) is a schematic diagram of the plug-in head in a specific embodiment (I); Figure 11 (b) is a schematic diagram of the plug-in head in a specific implementation (II); Figure 12 (a) is a partial structural diagram of the nail remover after the sleeve is removed in a specific embodiment (I); Figure 12 (b) is a partial structural diagram of the nail remover after the sleeve is removed in a specific embodiment (II).

[0019] Figure label: 1-Screwless plug rod system; 11-Screw rod; 12-Pin seat; 121-Gate; 13-Connecting rod; 14-U-shaped retainer; 141-U-shaped groove; 142-Retaining groove; 2-Outer sleeve; 201-Rotating window; 21-Inner channel; 211-Rotating section; 212-Limiting section; 213-Sliding section; 3-Plug-in head; 31-Connecting sleeve; 32-Plug-in rod; 321-Latch; 322-Hook; 4-Transmission assembly; 401-Sector groove; 401a-First sector groove wall; 401b-Second sector groove wall; 402-Rotating groove; 402a-First rotating groove wall; 402b-Second rotating groove wall; 403-Control 403a - Straight groove wall; 403b - Inclined groove wall; 41 - Rotating handle; 411 - Rotating part; 412 - Transition part; 413 - Handle part; 414 - Anti-slip part; 42 - Transmission rod; 43 - Core rod; 431 - Assembly part; 432 - Main rod part; 433 - Control part; 44 - Sleeve; 441 - Slide groove; 442 - Groove opening; 45 - First rotating pin; 46 - Second rotating pin; 47 - Third rotating pin; 48 - Connecting pin; 5 - Elastic element. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connected" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0022] Throughout the text, the terms “top,” “bottom,” “above,” “below,” and “on top” refer to the relative positions of components of the device, such as the relative positions of the top and bottom substrates within the device. It is understood that the device is multifunctional and independent of its spatial orientation.

[0023] The working surface of this invention can typically be a plane or a curved surface, and can be inclined or horizontal. For ease of explanation, the embodiments of this invention are placed on a horizontal surface and used on a horizontal surface, thereby defining "height" and "vertical".

[0024] One specific embodiment of the present invention discloses a nail remover for a screwless nail bar system, such as... Figures 2-12 As shown, it includes: Outer tube 2; The insertion head 3 is located at the end of the outer sleeve 2; the insertion head 3 is configured to have at least an open state and a tightened state, so that the insertion head 3 can be inserted into the slot 142 of the U-shaped bracket 14 of the screwless plug rod system 1, that is, the insertion head 3 can form a holding force on the U-shaped bracket. The transmission assembly 4 is configured to control the insertion head 3 to switch between an open state and a closed state in order to control the insertion head 3 to pull the U-shaped retainer out of the retainer of the screwless plug rod system.

[0025] The present invention relates to a screw releaser (hereinafter referred to as screw releaser) for a screwless stapler system. Through a transmission component, the state of the insertion and extraction head can be adjusted, thereby controlling the insertion and extraction head to pull the U-shaped retainer out of the staple holder of the screwless stapler system, thereby releasing the connecting rod and providing a safe and efficient solution for revision or adjustment surgery.

[0026] The U-shaped holder of the screwless plug rod system has a slot 142 on the outer wall of the U-shaped groove at a corresponding position. The nail holder 12 has a slot 121 at a position corresponding to the slot 142. The slot 121 can completely expose the slot 142, and the upper end of the slot 121 is open to ensure that the U-shaped holder can be pulled out without obstruction.

[0027] When the insertion head 3 is in the open state, its width is greater than the distance between the two slots 142, that is, the width is greater than the diameter of the U-shaped bracket, so that the insertion head 3 can be aligned and inserted into the two slots 142. When the insertion head 3 is in the tightened state, a part of the insertion head 3 (i.e., the hook 322 of the insertion head) is embedded in the slot 142, forming a radial clamping force on the U-shaped bracket. Applying an axial force to the insertion head 3 in the tightened state can pull the U-shaped bracket out of the pin seat.

[0028] To facilitate the movement of the transmission assembly, the outer sleeve 2 is provided with an inner channel 21 and a rotating window 201 communicating with the inner channel 21. The end of the inner channel 21 is open. The rotating window 201 is located on the upper part of the side wall of the outer sleeve 2.

[0029] According to one embodiment of the present invention, the transmission assembly 4 includes a rotating handle 41, a transmission rod 42, a core rod 43, and a sleeve 44.

[0030] One end of the rotating handle 41 is located in the inner channel 21 and is rotatably connected to the outer sleeve 2. The other end of the rotating handle 41 passes through the rotating window 201 and is located outside the outer sleeve 2. The rotating handle 41 can rotate relative to the outer sleeve 2. The first end of the rotating handle 41 (i.e., the end rotatably connected to the outer sleeve) is always located in the inner channel, and the top wall of the rotating window 201 is lower than the first end of the rotating handle 41 to prevent the rotating handle from accidentally protruding entirely through the rotating window and to ensure the transmission stability of the transmission component.

[0031] The transmission rod 42 is located between the rotating handle 41 and the core rod 42, and both ends of the transmission rod 42 are rotatably connected to the rotating handle 41 and the core rod 42, respectively. One end of the transmission rod 42 can rotate with the rotating handle 41, and drive the core rod 43 at the other end to move up and down along the center line OO of the inner channel. When the transmission assembly 4 is in the third state, the entire transmission rod is located in the inner channel 21; when the transmission assembly 4 is in the first and second states, the upper part of the transmission rod 42 passes through the rotating window 201 and is located outside the outer tube; the end of the transmission rod 42 is always located in the inner channel 21, and the bottom window wall of the rotating window 201 is higher than the end of the transmission rod to ensure that the transmission rod 42 does not accidentally pass entirely out of the rotating window 201, affecting the motion transmission of the transmission assembly.

[0032] Most of the core rod 43 (including the head end) is located inside the inner channel 21. The end portion of the core rod protrudes from the open opening of the inner channel and abuts against the plug head 3. The center line of the core rod 43 coincides with the center line AA of the inner channel. The core rod 43 is configured to move within the inner channel 21 as the rotating handle 41 is rotated. That is, the rotational motion of the rotating handle 41 is transmitted through the transmission rod 42 to form the linear reciprocating motion of the core rod 43.

[0033] The sleeve 44 is fitted over the outside of the insertion head 3 and connected to the core rod 43. The sleeve 44 is configured to move synchronously with the core rod 43, meaning the sleeve 44 can move up and down relative to the insertion head 3, while the insertion head 3, connected to the end of the outer sleeve 2, cannot move. When the sleeve 44 moves upward, the end portion of the insertion head 3 is exposed; when it moves downward, the end portion is gradually covered. It should be noted that the sleeve 44 is connected to the portion of the core rod 43 that protrudes from the inner channel (i.e., the end portion) to ensure that the synchronous movement of the sleeve with the core rod is not affected by the outer sleeve, thus improving the smoothness of the transmission assembly.

[0034] When the sleeve 44 and the core rod 43 move upward as the rotating handle 41 rotates outward (away from the outer sleeve), the sleeve gradually exposes the end part of the insertion head 3. When the rotating handle 41 is rotated outward to the maximum angle (let this angle be α), the insertion head 3 is opened to the maximum extent. When the sleeve 44 and the core rod 43 move downward as the rotating handle 41 rotates inward, the sleeve gradually covers the end part of the insertion head 3. When the rotating handle 41 is rotated inward to a certain angle (let this angle be β), the insertion head 3 is in a tightened state.

[0035] To facilitate the application of axial force to the insertion head 3 and more easily pull out the U-shaped bracket, as the handle 41 is gradually turned to the minimum angle with the outer sleeve (let this angle be γ), the end of the sleeve 44 abuts against the top end face of the nail seat 12 and applies an axial downward force to the nail seat 12. Correspondingly, the insertion head 3 applies an axial upward force to the U-shaped bracket. When the handle 41 is turned to angle γ, the insertion head 3 can just pull the U-shaped bracket out of the nail seat.

[0036] Let A be the rotation connection point between the rotating handle 41 and the outer sleeve 2, B be the rotation connection point between the rotating handle 41 and the transmission rod 42, and C be the rotation connection point between the transmission rod 42 and the core rod 43. Then, the rotation angle of the rotating handle is ∠BAC, where α > β > γ. In this embodiment, γ = 0°. It should be noted that since the beginning of the rotating handle and the beginning of the core rod are always located in the inner channel, the AC line always coincides with the center line OO.

[0037] Therefore, the transmission assembly includes at least three states. In the first state, the rotation angle of the rotating handle 41 is α, and the plug-in head 3 is in the open state. This state facilitates the connection of the plug-in head 3 to the U-shaped card holder, such as... Figure 3 As shown; in the second state, the rotation angle of the rotating handle 41 is β, and the insertion head 3 is in the tightened state. In this state, the insertion head 3 can clamp and hold the U-shaped card, as shown. Figure 4 As shown; in the third state, the rotation angle of the rotating handle 41 is γ, and the insertion / removal head 3 is in the tightened state, just enough to pull the U-shaped card holder out of the nail seat, as shown. Figure 5 As shown. It should be noted that the process of rotating the handle from angle β to γ ​​is a process of gradually applying an axial upward force to the U-shaped retainer (this force is applied through the insertion head) and an axial downward force to the pin holder (this force is applied through the sleeve) until the U-shaped retainer is pulled out of the pin holder, and then the connecting rod can be released from the U-shaped retainer.

[0038] In this embodiment, the rotating handle 41 includes a rotating part 411, a transition part 412, and a handle part 413 connected in sequence. The rotating part 411 is a straight plate. The extension direction of the handle part 413 is generally parallel (including parallel) to the rotating part 411, and the handle part 413 is located below the rotating part 411. The two ends of the transition part 412 are respectively connected to the end of the rotating part 411 and the beginning of the handle part 413. The transition part 412 is configured such that the handle part 413 always maintains a certain distance from the outer sleeve 2. Preferably, the transition part 412 is an arc-shaped transition plate. This configuration ensures that there is always a certain gap between the handle part 413 and the outer sleeve 2, making it convenient for the user to hold the handle part 413 and thus convenient to rotate the rotating handle 41. On the other hand, the arc-shaped transition part also makes the transmission of torque more stable.

[0039] For ease of operation, the outer side wall of the handle portion 413 (the side away from the rotating portion 411) is provided with an anti-slip portion 414. For example, the anti-slip portion 414 is wavy, and the wavy anti-slip portion extends from one end of the outer side wall of the handle portion to the other end. The anti-slip cloth plays an anti-slip role, making it convenient for the user to grip and apply force.

[0040] The first end of the rotating part 411 is rotatably connected to the outer sleeve 2, and the second end of the rotating part 411 is rotatably connected to the first end of the transmission rod 42. For example, the rotating part and the outer sleeve, as well as the rotating part and the transmission rod, are rotatably connected by rotating pins; that is, the rotating part and the outer sleeve are rotatably connected by a first rotating pin 45, and the rotating part and the transmission rod are rotatably connected by a second rotating pin 46.

[0041] To ensure smooth rotational transmission between the transmission rod 42 and the rotating handle 41, a sector-shaped groove 401 is provided at the connection between the rotating handle 41 and the transmission rod 42. The sector-shaped groove 401 provides sufficient space for the rotation of the transmission rod 42, allowing the transmission rod to rotate smoothly with the rotation of the rotating handle. Specifically, the sector-shaped groove 401 is located at the connection between the transition part 412 and the rotating part 411.

[0042] To ensure the structural stability and strength of the transmission assembly, the sector-shaped groove 401 includes a first sector-shaped groove wall 401a and a second sector-shaped groove wall 401b, which clamp the transmission rod 42 in the middle. In this embodiment, the rotating handle 41 includes two side plates of the same shape and an intermediate plate sandwiched between the two side plates. The intermediate plate has a sector-shaped opening at the connection between the transition part and the rotating part. The two side plates and the intermediate plate together limit the sector-shaped groove 401. Preferably, the rotating handle is integrally molded to ensure the structural strength of the rotating handle.

[0043] The core rod 43 includes an assembly part 431, a main rod part 432, and a control part 433 connected sequentially from top to bottom. The assembly part 431 is always located in the inner channel 21 and is rotatably connected to the end of the transmission rod 42. The end of the main rod part 432 extends out of the inner channel 21 and is located below the outer sleeve. The end of the main rod part 432 is connected to the sleeve 44, allowing the sleeve 44 to move synchronously with the core rod 43. The control part 433 cooperates with the plug-in head 3 to control the switching of the state of the plug-in head 3.

[0044] Specifically, the assembly part 431 is provided with a rotating groove 402 that is adapted to the end of the transmission rod 42. The rotating groove 402 includes a first rotating groove wall 402a and a second rotating groove wall 402b that are arranged opposite to each other. The end of the transmission rod 42 is sandwiched between the first rotating groove wall 402a and the second rotating groove wall 402b.

[0045] The control unit 433 is provided with two control slots 403 with opposite openings. Each control slot 403 includes at least a straight slot wall 403a and an inclined slot wall 403b. The straight slot wall 403a is vertically arranged. One end of the inclined slot wall 403a is connected to the end of the straight slot wall 403a, and the other end of the inclined slot wall 403a extends downward and outward. That is, the inclined slot wall 403b is located below the straight slot wall 403a, and the plane on which the inclined slot wall 403b is located is an inclined surface that slopes downward and outward. The insertion / extraction rod 3 is provided with a latch 321 that cooperates with the control slots 403, and the latch 321 abuts against the control slots 403. When the latch abuts against the straight groove wall 403a, the insertion head 3 is in a tightened state, that is, when the rotation angle of the rotating handle is between γ and β (including rotation angles γ and β), or when the transmission component is transitioning between the second and third states (including the second and third states). When the latch abuts against the inclined groove wall 403b, the insertion head 3 is in an extended state, that is, when the rotation angle of the rotating handle is between β and α (including rotation angle α, excluding rotation angle β), or when the transmission component is transitioning between the first and second states (including the first state, excluding the second state). When the core rod moves upward, the control groove 403 moves upward synchronously with the core rod, and the insertion head 3 gradually abuts against the inclined groove wall as the control groove 403 moves upward, changing the state of the insertion head 3 from a tightened state to an extended state. When the insertion head 3 abuts against the end of the inclined groove wall, the rotation angle of the rotating handle is α, that is, the transmission component is in the first state. As the core rod moves downward, the control groove 403 moves downward synchronously with the core rod. As the control groove 403 moves downward, the plug head gradually moves from the state of contacting the inclined groove wall to the state of contacting the straight groove wall. The state of the plug 3 also changes from the unfolded state to the tightened state.

[0046] To improve the structural stability of the core rod, the control groove 403 is located in the center of the control section 433, and the first end of the control section 433 (the end of the main rod) is connected to the sleeve 44.

[0047] For example, the assembly part 431 and the transmission rod 42 are rotatably connected by a third rotating pin 47. The core rod and the sleeve 44 are connected by a connecting pin 48, so that the sleeve 44 can move synchronously with the core rod 43.

[0048] When the transmission assembly is in the third state, the rotating part 411, the transmission rod 42, and the core rod 43 are all located in the inner channel, and their center lines coincide with the center line OO. The rotation connection point of the three is also located on the center line OO. The handle part 413 is approximately parallel to the outer wall of the outer sleeve 2. When the rotating handle is turned outward (i.e., when the transmission assembly gradually transitions to the second state and the first state), the end part of the rotating part 411 and the beginning part of the transmission rod 42 pass through the rotating window 201 and gradually rotate to the outside of the outer sleeve 2. The core rod gradually moves upward as the rotating handle moves outward, and the sleeve 44 also moves upward synchronously with the upward movement of the core rod, gradually exposing the end part of the plug-in head 3 until the plug-in head is unfolded into the open state. When the handle is rotated inward (i.e., when the transmission assembly transitions from the first state to the second state and back to the first state), the end portion of the rotating part 411 and the beginning portion of the transmission rod 42 gradually pass through the rotating window 201 and rotate into the inner channel. The core rod gradually moves downward as the handle rotates inward, and the sleeve 44 also moves downward synchronously with the core rod, gradually completely covering the end portion of the insertion head 3. During the process of the insertion head end being covered, its state changes from an open state to a tightened state. It should be noted that the beginning end of the core rod is always located in the inner channel 21, and the center line of the core rod always coincides with the center line OO.

[0049] The sleeve 44 is sleeved on the end portion of the core rod and outside the insertion head 3. The length of the sleeve 44 is less than the length of the insertion head 3 and cannot completely cover the insertion head 3. Specifically, the sleeve 44 can completely cover the end of the main rod portion 432 and the control portion 433 of the core rod, and cover most of the insertion head 3. When the sleeve 44 moves upward with the core rod, the sleeve 44 covers the head end of the insertion head 3 and exposes most of the end, and the insertion head 3 changes from a tightened state to an extended state. When the sleeve 44 moves downward with the core rod, the sleeve 44 covers the end of the insertion head and exposes most of the head, and the insertion head 3 changes from an extended state to a tightened state.

[0050] The sleeve 44 is shaped to fit both the insertion head 3 and the core rod 43. To ensure the stability of the insertion head 3 during state switching and to facilitate the application of force, the inner wall of the sleeve 44 is provided with a groove 441 that matches the insertion head 3. The groove 441 extends from below the connection between the sleeve and the core rod to the end of the sleeve 44. The insertion head 3 extends or retracts from the end of the sleeve 441 through the groove 441, thereby achieving the switching of the insertion head 3's state. The end of the sleeve 44 is provided with a slot 442 that mates with the connecting rod 13. When the transmission component is in the first and second states, the slot 442 is located directly above the connecting rod; when the transmission component is in the third state, the connecting rod 13 is embedded in the slot 442 to avoid the connecting rod affecting the contact between the sleeve and the nail seat, facilitating the application of an axially downward force to the nail seat through the sleeve. For example, the slot is semi-circular in shape.

[0051] Preferably, the center connecting line of the two slots 442 is perpendicular to the plane where the two slides are located, so as to improve the structural stability and strength of the nail remover.

[0052] To better define the state of the transmission assembly, the inner channel 21 is provided with a rotating section 211, a limiting section 212 and a sliding section 213 from top to bottom, and the diameter of the transmission section is greater than the diameter of the limiting section and the diameter of the sliding section.

[0053] The rotating window 201 is opened in the rotating section 211, and the assembly part of the rotating handle 41, the transmission rod 42 and the core rod 43 is located in the rotating section 211, which can ensure smooth motion transmission between the rotating handle 41, the transmission rod 42 and the core rod.

[0054] The end portion of the core rod passes through the limiting section and the sliding section and emerges from the opening of the inner channel. The diameter of the main rod portion 432 of the core rod matches the diameter of the sliding section 213, ensuring that the movement of the core rod is unaffected while also guaranteeing the stability of the movement. The diameter of the assembly portion 431 matches the diameter of the rotating section 211, that is, the diameter of the assembly portion 431 is larger than the diameter of the limiting section, to ensure that the assembly portion 431 is always located in the rotating section 211. This not only prevents the core rod 43 from accidentally falling out of the inner channel, but also more accurately defines the various states of the transmission assembly.

[0055] To improve the ease of use of the nail remover, the limiting section is provided with an elastic element 5. The elastic element 5 is sleeved on the first end of the main rod 432 and is limited between the assembly part 431 and the bottom of the limiting section. The elastic element 5 provides an upward thrust for the rotating handle to rotate outward, so that the rotating handle can be quickly and accurately rotated to the rotation angle α. When the transmission assembly is in the third state, the elastic element 5 is in a compressed state and is completely compressed within the limiting section 212, and the bottom of the assembly part 431 abuts against the bottom of the rotating section. When the transmission assembly switches between the second and first states, the elastic element 5 provides an upward thrust. Since the second state is a transitional state and does not require a long dwell time, the elastic element allows the transmission assembly to quickly position itself in the first state. This allows the insertion head to extend to its maximum extent, facilitating docking with the U-shaped retainer. Furthermore, when the handle is rotated inward, the elastic element needs to be compressed back to the limiting section 212. This requires resisting the elastic element's rebound force, making the user's force output more stable and providing cushioning. This prevents accidental pinching of the user during rapid force application and avoids sudden injury to the patient. It also reduces the risk of damage to the screwless pin system and makes it easier to remove the U-shaped retainer. For example, the elastic element is a spring.

[0056] The insertion / removal head 3 is fitted over the end portion of the core rod and can switch states as the core rod moves. Specifically, the insertion / removal head 3 includes a connecting sleeve 31 and two oppositely arranged insertion / removal rods 32. The first end of the connecting sleeve 31 is connected to the end of the outer sleeve 2, and the end of the connecting sleeve 31 is connected to the two insertion / removal rods 32, which clamp the core rod in the middle. The insertion / removal rod is located within a groove in the sleeve and is slidably connected to the groove. That is, the insertion / removal rod is inserted into the groove and extends or retracts along the groove to switch states. The insertion / removal rod is adapted to the groove. This arrangement improves the displacement stability of the sleeve and the state switching stability of the insertion / removal rod, thereby improving the operational stability of the nail remover. The connecting sleeve 31 is located above the connecting pin 48, and the plane where the two insertion rods 32 are located is perpendicular to the connecting pin 48, so as to ensure that the insertion rods 32 do not affect the synchronous movement of the sleeve 44 with the core rod. That is, the space left outside the two insertion rods 32 is sufficient for the core rod and sleeve to move up and down smoothly.

[0057] The insertion / removal rod 32 is provided with a latch 321 that mates with the control slot 403, and the latch abuts against the control slot. In this embodiment, the latch is located slightly below the center of the insertion / removal rod.

[0058] The bottom of the insertion / removal rod 32 is provided with hooks 322 that mate with the slots 142, so that the insertion / removal rod can clamp the U-shaped card holder. When the insertion / removal head 3 is in the open state, the distance between the two hooks is greater than the distance between the two slots 142, that is, the distance between the two hooks is greater than the diameter of the U-shaped card holder, so that the hooks can be aligned and inserted into the two slots 142. When the insertion / removal head 3 is in the tightened state, the hooks are embedded in the slots 142, forming a radial clamping force on the U-shaped card holder.

[0059] The screw remover of the present invention is a special instrument that can be used in revision surgery or intraoperative adjustments to safely remove the connecting rod that has been locked in the pedicle screw.

[0060] The purpose of this invention is to provide an implant rod removal device that can be precisely and securely connected to a locked U-shaped retainer and apply a controllable axial tensile force to completely pull the U-shaped retainer out of the staple holder, thereby releasing the connecting rod and providing a safe and efficient solution for revision or adjustment surgery.

[0061] Compared with the prior art, the beneficial effects of the present invention are at least as follows: Precise docking: The plug and socket are specially designed for the geometry of the U-shaped card holder, enabling fast and accurate docking. The connection is reliable, forming a solid force transmission interface with the U-shaped card holder to prevent slippage; The force is controllable, with a pure axial pulling force mode. The force is concentrated and the direction is controllable, which greatly reduces the impact of lateral force on the screw-bone interface and the risk of damaging surrounding tissues. Minimally invasive and safe, it avoids destructive operations such as knocking and prying, effectively preventing the generation of metal fragments and accidental damage to instruments; It improves efficiency, is simple and direct to operate, and can significantly shorten the time for internal fixation treatment in revision surgery.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A nail remover for a screwless nail bar system, characterized in that, include: Outer tube; A plug-in head is located at the end of the outer sleeve; The insertion head is configured to have at least an open state and a closed state, so that the insertion head can be engaged into the slot of the U-shaped retainer of the screwless plug rod system; The transmission assembly is configured to control the insertion head to switch between an open state and a closed state in order to control the insertion head to pull the U-shaped retainer out of the retainer of the screwless plug rod system.

2. The nail remover for a screwless nail bar system according to claim 1, characterized in that, The outer sleeve is provided with an inner channel and a rotating window communicating with the inner channel; The end of the inner channel is open; The rotating window is located on the upper part of the side wall of the outer sleeve.

3. The nail remover for a screwless nail bar system according to claim 2, characterized in that, The transmission assembly includes a rotating handle, a transmission rod, a core rod, and a sleeve; One end of the rotating handle is located in the inner channel and is rotatably connected to the outer tube, while the other end of the rotating handle passes through the rotating window and is located outside the outer tube; The transmission rod is located between the rotating handle and the core rod, and both ends of the transmission rod are rotatably connected to the rotating handle and the core rod, respectively. Most of the core rod is located within the inner channel, and the end portion of the core rod protrudes from the open opening of the inner channel and abuts against the plug head. The core rod is configured to move within the inner channel as the rotating handle is rotated. The sleeve is fitted over the outside of the insertion head and connected to the core rod. The sleeve is configured to move synchronously with the core rod.

4. The nail remover for a screwless nail bar system according to claim 3, characterized in that, The transmission component includes at least three states: a first state, a second state, and a third state. When the transmission assembly is in the first state, the rotation angle of the rotating handle is α, and the plug-in head is in the open state, ready to connect the plug-in head to the U-shaped card seat; When the transmission assembly is in the second state, the rotation angle of the rotating handle is β, and the insertion head is in the tightened state so that the insertion head can clamp and hold the U-shaped card. When the transmission assembly is in the third state, the rotation angle of the rotating handle is γ, and the insertion head is in the tightened state so as to just pull the U-shaped card seat out of the nail seat. Where α > β > γ; the process of rotating the handle from angle β to γ ​​is a process of gradually applying an axial upward force to the U-shaped card holder and an axial downward force to the nail holder, until the U-shaped card holder is pulled out of the nail holder.

5. The nail remover for a screwless nail bar system according to claim 4, characterized in that, The rotating handle includes a rotating part, a transition part, and a handle part connected in sequence, with the handle part located below the rotating part. The two ends of the transition part are respectively connected to the end of the rotating part and the beginning of the handle part. The transition portion is configured such that the handle portion always has a gap with the outer tube; The first end of the rotating part is rotatably connected to the outer sleeve, and the last end of the rotating part is rotatably connected to the first end of the transmission rod; The outer wall of the handle is provided with an anti-slip part; The connection between the rotating handle and the transmission rod is provided with a sector-shaped groove, which provides space for the rotation of the transmission rod.

6. The nail remover for a screwless nail bar system according to claim 4, characterized in that, The core rod is provided with two control grooves with openings facing away from each other. Each control groove includes at least a straight groove wall and an inclined groove wall. The straight groove wall is set vertically. One end of the inclined groove wall is connected to the end of the straight groove wall, and the other end of the inclined groove wall extends downward and outward. The insertion / removal rod is provided with a latch that cooperates with the control groove, and the latch abuts against the control groove; When the latch abuts against the straight groove wall, the insertion head is in a tightened state; When the latch abuts against the inclined groove wall, the insertion head is in an unfolded rotating state.

7. The nail remover for a screwless nail bar system according to claim 4, characterized in that, The sleeve is fitted onto the end portion of the core rod and the outside of the insertion head, and the shape of the sleeve is adapted to both the insertion head and the core rod. The inner wall of the sleeve is provided with a sliding groove that is adapted to the plug-in head. The sliding groove extends from below the connection between the sleeve and the core rod to the end of the sleeve. The plug-in head extends or retracts from the end of the sleeve through the sliding groove to realize the switching of the plug-in head state. The end of the sleeve is provided with a groove that mates with the connecting rod of the screwless plug rod system. When the transmission component is in the first state and the second state, the groove is located directly above the connecting rod. When the transmission component is in the third state, the connecting rod is embedded in the groove.

8. The nail remover for a screwless nail bar system according to any one of claims 4 to 7, characterized in that, The inner channel is provided with a rotating section, a limiting section and a sliding section from top to bottom, and the diameter of the transmission section is greater than the diameter of the limiting section and the diameter of the sliding section. The rotating window is located in the rotating section, and the assembly parts of the rotating handle, transmission rod, and core rod are located in the rotating section. The diameter of the rotating section matches the diameter of the assembly part, and the diameter of the sliding section matches the diameter of the main rod part of the core rod.

9. The nail remover for a screwless nail bar system according to claim 8, characterized in that, The limiting segment is equipped with an elastic element; The elastic element is sleeved on the first end portion of the main rod and is limited between the assembly portion and the bottom of the limiting section; The elastic element is configured to provide an upward thrust for the outward rotation of the rotary handle, so that the rotary handle can be quickly and accurately rotated to the rotation angle α.

10. The nail remover for a screwless nail bar system according to any one of claims 4 to 7, characterized in that, The plug-in head includes a connecting sleeve and two plug-in rods arranged opposite to each other; The first end of the connecting sleeve is connected to the end of the outer sleeve, and the end of the connecting sleeve is connected to two plug-in rods; The two insertion rods clamp the core rod in the middle, and the insertion rods are located in the groove of the sleeve, and the insertion rods are slidably connected to the groove; The connecting sleeve is located above the connecting pin, and the plane containing the two insertion rods is perpendicular to the connecting pin; The insertion / extraction rod is provided with a latch that mates with the control groove of the core rod, and the latch abuts against the control groove; The bottom of the insertion rod is provided with a hook that cooperates with the slot, so that the insertion rod can clamp the U-shaped card seat.

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