Intramedullary nail and intramedullary nail kit

Abstract

This invention discloses an intramedullary nail and an intramedullary nail kit. The intramedullary nail includes a strip-shaped internal fixation member and a spiral member surrounding the internal fixation member. A first end of the spiral member is connected to one end of the internal fixation member, and a second end of the spiral member extends beyond the spiral member. A gap exists between the internal fixation member and the spiral member. Both the internal fixation member and the spiral member are made of shape memory alloy. The spiral member is configured such that its diameter decreases during the transformation from martensitic to austenitic phase. The internal fixation member is configured such that its hardness increases during the transformation from martensitic to austenitic phase. The intramedullary nail of this invention has the advantages of easy implantation and good fixation effect, combining the fixation effects of an intramedullary nail and a metal cable.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to an intramedullary nail and an intramedullary nail kit. Background Technology

[0002] In daily life, humans often suffer fractures of slender bones such as the sternum and leg bones due to accidents. Current technology commonly uses intramedullary nails or metal cables to fix the fractures.

[0003] Intramedullary nails employ a central, axial fixation method, with the force line closer to the physiological axis of the bone, resulting in strong resistance to bending and torsion. Metal cables, on the other hand, offer advantages such as small incisions and good flexibility, allowing for 360-degree cerclage of bone fragments, conforming to irregular bone surfaces, and providing excellent reduction and fit, making them suitable for binding fractures with numerous bone fragments.

[0004] However, existing intramedullary nails are all installed far from the fracture site. The insertion and fixation of the intramedullary nail requires an intra-articular approach, inevitably causing iatrogenic damage to normal anatomical structures such as articular cartilage, joint capsule, and ligament insertions during the procedure. Postoperative complications such as joint adhesions, stiffness, chronic pain, and even traumatic arthritis are common, severely impacting the patient's postoperative joint function recovery.

[0005] Existing metal cables can only provide circumferential compression and clamping, but lack axial support, bending resistance, and rotation resistance, and cannot independently maintain the three-dimensional force line stability of the fracture ends of long bones. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention discloses an intramedullary nail and an intramedullary nail kit, which are easy to implant and have good fixation effect.

[0007] This invention is achieved through the following technical solution:

[0008] An intramedullary nail includes a strip-shaped internal fixation member and a spiral member surrounding the internal fixation member. A first end of the spiral member is connected to one end of the internal fixation member, and a second end of the spiral member extends beyond the spiral member. A gap exists between the internal fixation member and the spiral member. Both the internal fixation member and the spiral member are made of shape memory alloy. The spiral member is configured such that its diameter decreases during the transformation from martensitic to austenitic phase. The internal fixation member is configured such that its hardness increases during the transformation from martensitic to austenitic phase.

[0009] Furthermore, the internal fixation member has a first channel extending to the outer surface of the internal fixation member away from the end of the spiral member; the spiral member has a second channel communicating with the first channel, the second channel extending to the outer surface of the spiral member away from the end of the internal fixation member; the first channel and the second channel are configured for the passage of fluid.

[0010] Furthermore, the inner fixing member has a breaking component at one end away from the spiral member; the breaking component includes an anchor, a breaking member, a fluid driving component, and a connector connecting the anchor and the breaking member, the fluid driving component being in communication with the first channel; the anchor is configured to be displaced in a direction away from the axis of the inner fixing member; the breaking member is configured to be displaced along the axis of the inner fixing member and away from the inner fixing member; the fluid driving component is configured to drive the anchor to produce displacement and maintain the displacement amount and subsequently drive the breaking member to produce displacement.

[0011] Furthermore, the connector is a housing with a cavity, the housing having a first through hole for accommodating the anchor and a second through hole for accommodating the breaking member, both the first and second through holes communicating with the cavity, one end of the anchor and one end of the breaking member being located within the cavity, and the fluid driving component being located within the cavity; the anchor and the breaking member, after being driven by the fluid driving component to their extreme positions, both have their ends away from the cavity located on the outer surface of the housing.

[0012] Furthermore, the fluid-driven component is a bladder that expands after fluid is introduced. The bladder is connected to the first channel. The bladder has a contracted state and is located on the side of the anchor facing the inner fixing member in the contracted state. The bladder in the contracted state is configured to expand toward the breaking member. The expanded bladder drives the anchor and the breaking member to generate displacement.

[0013] Furthermore, a return spring is connected between the breaking member located within the cavity and the inner wall of the cavity for driving the breaking member to move towards the inner fixing member.

[0014] An intramedullary nail kit includes a cold source and any of the aforementioned intramedullary nails. The cold source is configured such that its temperature is lower than a preset temperature setting, and the cold source exchanges heat with both the internal fixation member and the spiral member, thereby causing both the internal fixation member and the spiral member to be in the martensitic phase.

[0015] Furthermore, it also includes a columnar handpiece, the surface of which has a mating portion for supporting the inner fixing member. The mating portion is configured to allow the inner fixing member to slide within the mating portion along the axial direction of the handpiece and to slide out of the mating portion. The spiral member is wound around the outer wall of the handpiece, and at least a portion of the body of the handpiece is accommodated in the gap between the inner fixing member and the spiral member.

[0016] Furthermore, it also includes a fluid pump, which is connected to the second channel, and the cold source is a coolant that flows in the first channel and the second channel driven by the fluid pump.

[0017] Furthermore, it also includes a control module and a driver disposed on the handheld device, the driver being configured to drive the inner fixing member to slide within the mating portion; the control module being configured to selectively and independently trigger the driver or the fluid pump to operate, and to achieve alternating operation of the two.

[0018] Compared with existing technologies, the advantages of this invention are as follows: By using a cold source, internal fixation device, and spiral device, during intramedullary nail implantation, the cold source keeps the internal fixation device and spiral device at a temperature far below the preset temperature (human body temperature). At this temperature, both the internal fixation device and spiral device are in the martensitic phase, making them relatively soft and facilitating the internal fixation device's entry into the medullary cavity through an opening near the fracture site. Simultaneously with the internal fixation device entering the medullary cavity, the spiral device can be rotated to wrap around the outside of the fracture fissure. After the internal fixation device is implanted into the medullary cavity and the spiral device is secured to the outside of the bone with the fracture fissure, the cold source is removed. The internal fixation device and spiral device then heat up to the preset temperature (human body temperature) under the influence of human body temperature, transforming into the austenitic phase. At this point, the internal fixation device becomes harder, providing resistance to bending and rotation of the fractured bone, while the diameter of the spiral device decreases, thus achieving binding and fixation of the fractured bone. Simultaneously, the spiral device also hardens. Therefore, the intramedullary nail of this invention has the advantages of easy implantation and good fixation effect, combining the fixation effects of both intramedullary nails and metal cables. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the intramedullary nail of the present invention; Figure 2 This is a schematic diagram of the intramedullary nail of the present invention being inserted into the fractured right bone; Figure 3 This is a schematic diagram of the intramedullary nail of the present invention being inserted into the fractured left bone; Figure 4 This is a schematic diagram illustrating the implantation of the intramedullary nail of the present invention at the fracture site; Figure 5 This is a three-dimensional schematic diagram of the intramedullary nail of the present invention after it has been installed on the handheld device; Figure 6 This is a schematic diagram of the capsule being in a partially inflated state in the breaking component of the present invention; Figure 7 This is a schematic diagram of the capsule being in a fully expanded state in the breaking component of the present invention; Figure 8 This is a schematic diagram of a breaking component according to a first other embodiment of the present invention; Figure 9 This is a schematic diagram of a breaking component according to a second embodiment of the present invention; Figure 10 This is a schematic diagram of a breaking component according to a third other embodiment of the present invention.

[0020] In the picture: 1-Internal fixing component; 2-Spiral component; 3-Breaking component; 3a-Anchor; 3b-Breaking component; 3c-Shell; 3d-Bag body; 3e-Solid block; 3f-First cylinder; 3g-Second cylinder; 3h-Drive block; 3i-First cavity; 3j-Second cavity; 3k-Pressure valve; 4-Handheld device; 5-Driver. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] 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, or an integral connection; they can refer to a mechanical connection or an electrical 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] To overcome the drawbacks of large incisions from intramedullary nail implantation and the poor bending and rotation resistance of metal cables, this invention discloses an intramedullary nail kit, such as... Figure 1 As shown, it includes an intramedullary nail and a cold source.

[0025] Among them, such as Figure 1 As shown, the intramedullary nail includes a strip-shaped internal fixation member 1 and a spiral member 2 surrounding the internal fixation member 1. The internal fixation member 1 and the spiral member 2 are coaxially arranged. The first end of the spiral member 2 is connected to the first end of the internal fixation member 1, and the second end of the internal fixation member 1 extends out of the spiral member 2. There is a gap between the internal fixation member 1 and the spiral member 2. Both the internal fixation member 1 and the spiral member 2 are made of shape memory alloy. The spiral member 2 is configured such that its diameter decreases during the transformation from martensitic phase to austenitic phase.

[0026] Preferably, the diameter of each spiral coil of the spiral component 2 can be uniform or different. The size of the diameter of each spiral coil of the spiral component 2 depends on the bone condition at the intramedullary nail implantation site. If the diameter of each bone position at the intramedullary nail implantation site is roughly the same (such as the fibula), then a spiral component 2 with a uniform diameter of each spiral coil can be selected. If the bone position at the intramedullary nail implantation site has different thicknesses (such as the tibia near the joint), then a spiral component 2 with a gradually increasing diameter of each spiral coil can be selected.

[0027] Regarding the cold source, its temperature is configured to be lower than a preset temperature setting. The cold source is used to exchange heat with the internal fixation component 1 and the spiral component 2, causing them to cool and enter the martensitic phase. For applications involving the fixation of fractured bones, the preset temperature is preferably set to normal human body temperature (37 degrees Celsius), and the cold source temperature is preferably set to 0 to 5 degrees Celsius. When the intramedullary nail of this invention is used for routine connection of other broken tubes, the preset temperature can be the local air temperature (e.g., 20 degrees Celsius), and the cold source temperature can be -10 degrees Celsius.

[0028] Fractured bones are defined as either fractured left bones or fractured right bones, such as... Figures 2 to 4 As shown, the method of using the intramedullary nail kit of the present invention is as follows: Step 1: Drill an opening near the fracture crack in the fractured right bone to connect to the medullary cavity.

[0029] Step 2: Start the cold source, and the inner fixing part 1 and the spiral part 2 will cool down rapidly, so that both the inner fixing part 1 and the spiral part 2 are in the martensitic phase.

[0030] Step 3: As Figure 2 As shown, the second end of the driving internal fixation device 1 enters the medullary cavity of the fractured right bone through an opening that connects to the medullary cavity.

[0031] Step Four: As Figure 3 As shown, the internal fixation device 1 is driven from the medullary cavity of the fractured right bone to the medullary cavity of the fractured left bone. At this time, since the internal fixation device 1 is in the martensitic phase, the internal fixation device 1 is very easy to deform. Therefore, the internal fixation device 1 is more likely to be bent and enter the medullary cavity of the fractured left bone.

[0032] Step 5: As the internal fixation device 1 enters the medullary cavity of the fractured left bone, the internal fixation device 1 and the spiral device 2 are driven to rotate together with the internal fixation device 1 as the axis. The spiral device 2 is continuously rolled out from the second end of the spiral device 2 through the gap between two adjacent spiral coils of the spiral device 2, and through the gap between the internal fixation device 1 and the spiral device 2. During the continuous rotation of the spiral device 2, the spiral device 2 will also be rolled out to the outside of the fractured left bone.

[0033] Step Six: Through continuous driving of internal fixation component 1 into the medullary cavity of the fractured left bone, and through the continuous rotation of internal fixation component 1 and spiral component 2, as... Figure 4 As shown, the internal fixation device 1 is ultimately located in the medullary cavity of the fractured left and right bones, while the spiral device 2 is wrapped around the outside of the fractured left and right bones, and the fracture crack is wrapped by the spiral device 2.

[0034] Step 7: Remove the cold source. Internal fixation component 1 and spiral component 2 heat up due to body temperature, transforming into the austenitic phase. During the transformation from martensitic to austenitic phase, the diameter of spiral component 2 decreases, tightly securing the bone at the fracture site. During the transformation from martensitic to austenitic phase, internal fixation component 1 can be straightened or curved depending on the type of bone being implanted. Furthermore, since both internal fixation component 1 and spiral component 2 are in the austenitic phase, their stiffness and hardness are higher than those in the martensitic phase. Therefore, internal fixation component 1 and spiral component 2 provide better fixation for the fractured bone.

[0035] When it is necessary to remove the intramedullary nail from the body, simply bring the cold source back into contact with the internal fixation component 1 and the spiral component 2, so that the internal fixation component 1 and the spiral component 2 will revert to the martensitic phase.

[0036] The intramedullary nail and its kit of the present invention utilize a cold source to regulate the transformation of the internal fixation component 1 and the spiral component 2 between martensitic and austenitic phases. Leveraging the flexibility of martensitic shape memory alloys, the intramedullary nail is easily implanted into the fractured bone through the fracture fissure, resulting in a smaller incision. The length of the internal fixation component 1 is significantly shorter than that of an intramedullary nail implanted from the joint end, reducing installation difficulty. Furthermore, the length of the internal fixation component 1 can be adjusted to meet the implantation needs of bones of different lengths. Simultaneously, utilizing the automatic deformation property of the shape memory alloy during the martensitic-to-austenitic phase transformation, the spiral component 2 tightly binds the fractured bone at the fracture fissure, achieving the function of a traditional metal cable. Also utilizing the high hardness and high strength of the austenitic shape memory alloy, the internal fixation component 1, located in the medullary cavity of the fractured left and right bones, effectively achieves anti-bending and anti-rotation functions for the fractured bone, achieving the function of a traditional intramedullary nail. Therefore, the intramedullary nail of the present invention has the advantages of easy implantation and good fixation effect, combining the fixation effects of both intramedullary nails and metal cables. In addition, the spiral component 2 also fixes the fixator 1 in the medullary cavity, making the internal fixator 1 less prone to movement; there is no need to worry about the risk of bolts loosening during use, which is a common problem with traditional intramedullary nails that use bolts for fixation.

[0037] The intramedullary nail and intramedullary nail kit of the present invention have many technical features, such as the detailed structure of the intramedullary nail and other structures of the intramedullary nail kit, which can be implemented in various ways. In the following detailed description of each technical feature, including the detailed structure of the intramedullary nail, one specific implementation is selected, and this embodiment is referred to as "this embodiment." Other implementations of the numerous features, including the detailed structure of the intramedullary nail, are referred to as "other embodiments," which are briefly described below.

[0038] In this embodiment, as Figure 5 As shown, the intramedullary nail kit also includes a columnar handpiece 4. The surface of the handpiece 4 has a mating portion for supporting the internal fixation member 1. The mating portion is configured to allow the internal fixation member 1 to slide within the mating portion along the axial direction of the handpiece 4, and the internal fixation member 1 can slide out of the mating portion. A helical member 2 is wound around the outer wall of the handpiece 4, and at least a portion of the body of the handpiece 4 is accommodated in the gap between the internal fixation member 1 and the helical member 2. Preferably, a portion of the body of the handpiece 4 is accommodated in the gap between the internal fixation member 1 and the helical member 2. When the handpiece 4 is fully accommodated in the gap between the internal fixation member 1 and the helical member 2, the operator's fingers need to be inserted into the gaps between the coils in the helical member 2 to grasp the handpiece 4.

[0039] Therefore, between steps one and two, there is a step of fixing the intramedullary nail to the handheld device 4, with the gap between the internal fixation member 1 and the spiral member 2 used to accommodate the handheld device 4. During step four, the internal fixation member 1 is driven to slide towards the sliding mating part, that is, to slide outwards along the axis of the handheld device 4, allowing the internal fixation member 1 to enter the medullary cavity of the fractured left bone from the medullary cavity of the fractured right bone. At this time, both the internal fixation member 1 and the spiral member 2 gradually disengage from the handheld device 4. In step five, the handheld device 4 is rotated so that the internal fixation member 1 and the spiral member 2 rotate together. In step six, when the spiral member 2 is wrapped around the outside of both the fractured left and right bones, both the internal fixation member 1 and the spiral member 2 separate from the handheld device 4.

[0040] The present invention, through the provision of a handheld device 4, facilitates the operator's implantation of the intramedullary nail into the human body. In other embodiments, the handheld device 4 may be omitted, and the operator may hold and rotate the spiral component 2 to implant the intramedullary nail into the human body.

[0041] In this embodiment, as Figure 5 As shown, the mating part is a groove provided on the side wall surface of the handheld device 4 and arranged along the axial direction of the handheld device 4. The groove extends to the first end of the handheld device 4 and is used to support the internal fixation member 1. In step four, the internal fixation member 1 is driven to move towards the first end of the handheld device 4 within the groove until, in step six, the internal fixation member 1 is completely separated from the first end of the handheld device 4. By setting the mating part as a groove, the present invention facilitates the reduction of the volume after the intramedullary nail and the handheld device 4 are mated. In other embodiments, the mating part can also be two parallel limiting strips provided on the surface of the handheld device 4, with the length direction of both limiting strips arranged along the axial direction of the handheld device 4, and the internal fixation member 1 disposed between the two limiting strips.

[0042] In this embodiment, as Figure 1 As shown, the internal fixation member 1 has a first channel extending to the outer surface of the end of the internal fixation member 1 away from the spiral member 2. The spiral member 2 has a second channel communicating with the first channel, extending to the outer surface of the end of the spiral member 2 away from the internal fixation member 1. The first and second channels are configured to allow fluid to pass through. The cold source is a fluid, which can be cold air or a coolant, such as saline solution. After the cold source in its fluid state flows through the first and second channels, both the internal fixation member 1 and the spiral member 2 exchange heat with the cold source, thereby causing both the internal fixation member 1 and the spiral member 2 to be in the martensitic phase. This invention, through the arrangement of the first and second channels, facilitates continuous heat exchange between the internal fixation member 1 and the spiral member 2 and the cold source, facilitating the surgical procedure. In other embodiments, both the internal fixation member 1 and the spiral member 2 can be solid rods, and the cold source can be ice. Before implantation of the intramedullary nail, both the internal fixation member 1 and the spiral member 2 are placed in ice to cool them down.

[0043] In this embodiment, as Figure 1 , Figure 6 and Figure 7 As shown, the end of the internal fixation member 1 away from the spiral member 2 is provided with a breaking component 3. The purpose of the breaking component 3 is to break up substances such as yellow bone marrow in the medullary cavity, creating a channel for the internal fixation member 1 to smoothly enter the medullary cavity of the fractured right bone from the fractured left bone. Specifically, the breaking component 3 is provided at the end of the internal fixation member 1 away from the spiral member 2. The breaking component 3 includes an anchor 3a, a breaking component 3b, a fluid driving component, and a connector connecting the anchor 3a and the breaking component 3b. The fluid driving component is in communication with the first channel. The anchor 3a is configured to be displaced in a direction away from the axis of the internal fixation member 1. The breaking component 3b is configured to be displaced along the axis of the internal fixation member 1 and in a direction away from the internal fixation member 1. The fluid driving component is configured to drive the anchor 3a to produce displacement, maintain the displacement amount, and subsequently drive the breaking component 3b to produce displacement.

[0044] In detail, if the breaking component 3 is not set, when the internal fixation component 1 is blocked by substances such as yellow bone marrow during its movement in the bone marrow cavity, the internal fixation component 1 is in the martensitic phase at this time, and the internal fixation component 1 is relatively soft. The internal fixation component 1 is difficult to stably break the substances such as yellow bone marrow, and in this process, it is easy to scratch the inner wall of the bone marrow cavity. Therefore, after setting the breaking component 3, during the process of driving the internal fixation member 1 from the medullary cavity of the fractured right bone to the medullary cavity of the fractured left bone in step four, initially the fluid driving component does not drive the anchor 3a to produce displacement. There is a gap between the anchor 3a and the inner wall of the medullary cavity, allowing the breaking component 3 to move freely within the medullary cavity. When the breaking component 3 and the internal fixation member 1 are obstructed by the yellow bone marrow and have difficulty moving within the medullary cavity (the breaking component 3b abuts against the yellow bone marrow), the fluid, as a cold source, enters the fluid driving component after passing through the second and first channels in sequence. The fluid driving component drives the anchor 3a to produce displacement and maintains the displacement. At this time, since the anchor 3a is displaced in the direction away from the internal fixation member 1, after the anchor 3a abuts against the inner wall of the medullary cavity, it can lock the connector within the medullary cavity, making it difficult for the connector to move along the length of the medullary cavity. At this time, the fluid driving component drives the breaking component 3b to produce displacement. The breaking component 3b has a pointed tip on the side away from the internal fixation member 1, and the movement of the breaking component 3b creates a channel in the yellow bone marrow. Subsequently, the fluid in the fluid-driven component is removed, driving the internal fixation member 1 to move within the medullary cavity. Anchors 3a and the breaking component 3b, no longer driven by the fluid-driven component, return to their original positions. When the breaking component 3 and the internal fixation member 1 are again obstructed by the yellow bone marrow, the fluid-driven component again drives the anchors 3a and the breaking component 3b to displace. This invention, through the setting of the breaking component 3, progressively breaks down substances such as yellow bone marrow obstructing the advancement of the internal fixation member 1 within the medullary cavity, reducing damage to the interior of the medullary cavity. In other embodiments, the breaking component 3 may not be provided, but the obstructions within the medullary cavity need to be cleared before the internal fixation member 1 enters the medullary cavity, i.e., a reaming operation (reaming may cause extensive damage to the blood supply of the bone marrow and endosteal membrane, potentially leading to intramedullary hypertension, fat embolism, and thermal necrosis of bone cells, significantly increasing the risk of infection, osteomyelitis, and iatrogenic fractures). After the internal fixation member 1 enters the medullary cavity, the first channel flows out physiological saline at a temperature lower than human body temperature.

[0045] In this embodiment, as Figure 5As shown, the intramedullary nail kit also includes a fluid pump, which is connected to the second channel. The cold source is a coolant that flows in the first and second channels driven by the fluid pump. Preferably, the coolant is physiological saline at 0 to 5 degrees Celsius. Specifically, the first end of the handheld device 4 is provided with a liquid supply connector that can be connected to the second channel. The handheld device 4 has a reservoir for containing the coolant. The fluid pump can be installed inside the handheld device 4 and connected to the liquid supply connector and the reservoir. The handheld device 4 can also be equipped with a liquid supply pipe for supplying the reservoir. Through the fluid pump, the present invention allows for controlled injection or extraction of liquid into the fluid-driven components, thereby conveniently controlling the movement of the anchor 3a and the breaking component 3b. Simultaneously, during the continuous injection or extraction of liquid by the fluid pump, the coolant in the first and second channels is continuously replaced, ensuring that both the internal fixation component 1 and the spiral component 2 stably maintain the martensitic phase. In other embodiments, an air pump can be used instead of a fluid pump, but in this case, the cold source is cold air that flows in the first and second channels driven by the air pump.

[0046] In this embodiment, as Figure 5 As shown, the intramedullary nail kit also includes a control module and an actuator 5 mounted on the handheld device 4. The actuator 5 is configured to drive the internal fixation member 1 to slide within the mating portion. Specifically, the actuator 5 can be a cylinder with its output end extending out and positioned within a groove. A push plate is connected to the output end of the cylinder, and the operation of the cylinder pushes the push plate, thereby pushing the internal fixation member 1 to slide within the mating portion. Alternatively, the actuator 5 can be a motor and push plate mounted within the groove, with the motor's output end threaded into the push plate. The motor's rotation drives the push plate to slide within the groove, thereby moving the internal fixation member 1. Regarding the control module, it is configured to selectively and independently trigger either the actuator 5 or the fluid pump, and to alternate between the two. Specifically, the control module first controls the actuator 5 to operate, pushing the internal fixation member 1 a certain distance (e.g., one centimeter) away from the handheld device 4; then, the control module stops the actuator 5 and drives the fluid pump, causing the breaking component 3 to clear some material from the medullary cavity that is obstructing the advancement of the internal fixation member 1; finally, the control module stops the fluid pump and controls the actuator 5 to operate. Similarly, the control module sequentially controls the actuator 5 and the fluid pump to work alternately, allowing the internal fixation device 1 to move smoothly within the medullary cavity. This invention effectively controls the automatic movement of the internal fixation device 1 within the medullary cavity through the control module and actuator 5. In other embodiments, to reduce costs, the control module and actuator 5 may be omitted. Instead, the fluid pump is manually controlled to drive the breaking component 3 to break up substances such as yellow bone marrow within the medullary cavity, creating a channel for the movement of the internal fixation device 1. When the fluid pump is not working, the internal fixation device 1 is manually pushed to slide in the groove until it is blocked by yellow bone marrow or other substances, at which point the fluid pump is manually controlled again.

[0047] In this embodiment, as Figure 6 and Figure 7 As shown, the connector is a housing 3c with a cavity. The housing 3c has a first through hole for accommodating an anchor 3a and a second through hole for accommodating a breaking member 3b. Both the first and second through holes communicate with the cavity. One end of both the anchor 3a and the breaking member 3b is located within the cavity, and a fluid-driven component is disposed within the cavity. The anchor 3a is configured to move within the first through hole along its axial direction, but cannot leave the first through hole. The breaking member 3b is configured to move within the second through hole along its axial direction, but cannot leave the second through hole. Essentially, the anchor 3a and the breaking member 3b are movably connected through the housing 3c. When the anchor 3a and the breaking member 3b are displaced to their extreme positions by the fluid-driven component, the ends of both, away from the cavity, are located on the outer surface of the housing 3c.

[0048] In detail, the shell 3c is cylindrical and connected to the internal fixation member 1. The shell 3c and the internal fixation member 1 are coaxially arranged. The breaking member 3b is located at the end of the shell 3c away from the internal fixation member 1. Multiple anchors 3a are provided and are located on the side wall of the shell 3c. Each anchor 3a is symmetrically arranged along the axis of the shell 3c. The anchors 3a are configured such that when no fluid is introduced into the fluid driving component in the cavity, they do not protrude from the outer surface of the shell 3c within the first through hole, facilitating the movement of the shell 3c within the bone marrow cavity. When fluid flowing in from the first channel is introduced into the fluid driving component in the cavity, the fluid driving component first drives the anchors 3a to extend outward from the shell 3c and protrude from the outer surface of the shell 3c. Due to the extension of the anchors 3a, the radial radius of the breaking component 3 increases, and the shell 3c is stuck within the bone marrow cavity. Subsequently, the fluid-driven component displaces the breaking member 3b, causing it to extend away from the internal fixation member 1. Since the housing 3c is already fixed within the bone marrow cavity by the anchor 3a, the extension of the breaking member 3b can break the yellow bone marrow within the bone marrow cavity. When the fluid is removed from the fluid-driven component, it can no longer provide the anchor 3a and the breaking member 3b with a force that moves them outward from the housing 3c. Therefore, as the internal fixation member 1 moves, the anchor 3a will move towards the cavity after encountering the inner wall of the bone marrow cavity; similarly, the breaking member 3b will move towards the cavity after encountering the yellow bone marrow. This invention effectively protects the fluid-driven component through the design of the housing 3c and also facilitates the entry of the breaking component 3 into the bone marrow cavity.

[0049] In other embodiments, the connector may not be the housing 3c. For details, see... Figure 8As shown, the connecting component is a solid block 3e connected to the inner fixing component 1. The fluid driving components are a first cylinder 3f and a second cylinder 3g. The solid block 3e is coaxially arranged with the inner fixing component 1. The first cylinder 3f is connected to the end of the solid block 3e away from the inner fixing component 1. The breaking component 3b is connected to the output end of the first cylinder 3f, and the output end of the first cylinder 3f can extend and retract along the axis of the inner fixing component 1. The second cylinder 3g is connected to the side wall of the solid block 3e, and the anchor 3a is connected to the output end of the second cylinder 3g, and the output end of the second cylinder 3g can extend and retract along the axis perpendicular to the inner fixing component 1. At this time, the anchor 3a and the breaking component 3b pass through. There are two first channels and two second channels, and one of the first channels is connected to the first cylinder 3f and fixedly connected to the solid block 3e, while the other first channel is connected to the second cylinder 3g. The operator can first control the second cylinder 3g to extend, thereby causing the anchor 3a to move away from the solid block 3e. After controlling the second cylinder 3g to remain extended, the operator controls the first cylinder 3f to extend, thereby causing the anchor 3a to move away from the inner fixing member 1.

[0050] In other embodiments, such as Figure 9 As shown, the connector is still the housing 3c, but unlike this embodiment, it does not use a fluid-driven component to drive the anchor 3a and the breaking component 3b to produce displacement. Instead, a driving block 3h disposed within the cavity drives the anchor 3a to produce displacement and maintains the displacement amount, and subsequently can still drive the breaking component 3b to produce displacement. Specifically, the cavity is rectangular, and the driving block 3h is also rectangular and slides along the axis of the inner fixing component 1 within the cavity. When the inner fixing component 1 is moved, the driving block 3h is positioned on the side of the anchor 3a facing the inner fixing component 1. When the breaking component 3 needs to work, the driving block 3h moves away from the inner fixing component 1. One end of the anchor 3a located within the cavity has a first guide slope facing the inner fixing component 1. During the movement of the driving block 3h, the driving block 3h abuts against the first guide slope and drives the anchor 3a to move away from the cavity. Subsequently, the drive block 3h continues to move. Because the drive block 3h has thickness, even as the drive block 3h continues to move, the first guide slope still abuts against the surface of the drive block 3h, and the anchor 3a remains in the extended state. As the drive block 3h moves, it abuts against the breaking member 3b and pushes the breaking member 3b to move away from the inner fixing member 1.

[0051] In this embodiment, as Figure 6 and Figure 7As shown, the fluid-driven component is a capsule 3d that expands after fluid is introduced. The capsule 3d is connected to the first channel. Preferably, the capsule 3d is configured to expand after 0 to 5% saline solution flowing in through the first channel. The capsule 3d can also expand by introducing gas. The capsule 3d has a contracted state, and the capsule 3d in the contracted state is located on the side of the anchor 3a facing the inner fixing member 1. The capsule 3d in the contracted state is configured to expand toward the breaking member 3b, and the expanded capsule 3d drives the anchor 3a and the breaking member 3b to produce displacement.

[0052] In detail, the workflow of the capsule 3d is as follows: When the internal fixation component 1 moves within the bone marrow cavity, the capsule 3d is in a contracted state, at which point the anchor 3a cannot exert a gripping force on the inner wall of the bone marrow cavity. When the breaking component 3 needs to operate, a fluid pump injects physiological saline into the capsule 3d. Subsequently, the capsule 3d expands towards the breaking component 3b. During the expansion, the capsule 3d first holds against the anchor 3a, causing the anchor 3a to move outward from the shell 3c. At this time, the anchor 3a holds against the inner wall of the bone marrow cavity, and the shell 3c remains stationary with the assistance of the anchor 3a. Subsequently, the capsule 3d is driven to continue expanding. The expanding capsule 3d keeps the anchor 3a extended, and the expanding capsule 3d also pushes the breaking component 3b away from the internal fixation component 1, thereby breaking up substances such as yellow bone marrow within the bone marrow cavity. When the capsule 3d expands to its maximum state, the breaking component 3b also moves to its furthest position away from the internal fixation component 1. Subsequently, a fluid pump is used to remove the saline solution from the capsule 3d, causing the capsule 3d to return to its contracted state. Due to the influence of body temperature, the temperature of the saline solution in the first and second channels will rise. After the saline solution in the capsule 3d is removed, when injecting saline solution into the capsule 3d again, saline solution at a temperature of 0 to 5 degrees Celsius can be re-injected to ensure that the internal fixation component 1 and the spiral component 2 remain in a martensitic phase state below body temperature for a long period of time. This invention, through the design of the capsule 3d, makes the structure of the breaking component 3 simple, easy to manufacture, and the capsule 3d, located within the shell 3c, is less prone to damage.

[0053] In other embodiments, such as Figure 10As shown, the fluid-driven component may not use a capsule 3d. The cavity may include a first cavity 3i, a second cavity 3j, and a pressure valve 3k. The first cavity 3i is connected to the first channel, and one end of the anchor 3a is located within the first cavity 3i. The first cavity 3i is configured such that after fluid is injected into it, it can push the anchor 3a to move away from the shell 3c. One end of the rupture member 3b is located within the second cavity 3j. The rupture member 3b can move within the second cavity 3j and divides the second cavity 3j into a left cavity and a right cavity. The right cavity is connected to the first cavity 3i via the pressure valve 3k. The pressure valve 3k is configured to open after exceeding a set pressure. At this time, the operation of the rupture component 3 is as follows: the fluid pump first injects saline solution into the first cavity 3i, causing the anchor 3a to move away from the shell 3c. Subsequently, saline solution is injected into the first cavity 3i until the water pressure in the first cavity 3i is greater than the opening pressure of the pressure valve 3k. The saline solution flows into the right cavity through the pressure valve 3k, pushing the breaking member 3b to move away from the internal fixation member 1.

[0054] In this embodiment, as Figure 6 and Figure 7 As shown, a return spring is connected between the rupture element 3b located within the cavity and the inner wall of the cavity, used to drive the internal fixation element 1 to move towards the cavity. Under the action of the return spring, the rupture element 3b always abuts against the cyst 3d. During the expansion of the cyst 3d, the cyst 3d continues to abut against the rupture element 3b and moves away from the internal fixation element 1, at which time the return spring is compressed. After the anchor 3a extends and abuts against the inner wall of the bone marrow cavity, as the cyst 3d continues to expand, the rupture element 3b continues to move away from the internal fixation element 1. When the saline solution in the cyst 3d is removed, the rupture element 3b moves towards the internal fixation element 1 under the action of the return spring. This invention, through the setting of the return spring, allows the rupture element 3b to automatically retract during the movement of the internal fixation element 1. In other embodiments, the return spring may not be provided. In this case, before injecting saline into the capsule 3d, the breaking member 3b should be made to hold the yellow bone marrow in the bone marrow cavity, and the internal fixation member 1 should be moved toward the yellow bone marrow that is held by the breaking member 3b, so that the breaking member 3b retracts into the bone marrow cavity.

[0055] In this embodiment, as Figure 6As shown, the breaking member 3b located within the cavity has a second guide slope on the side facing the anchor 3a. When the bladder 3d is in a contracted state, under the action of the return spring, the second guide slope is also located on the side of the anchor 3a facing the inner fixing member 1. As the bladder 3d expands, the second guide slope moves away from the inner fixing member 1. During the movement of the second guide slope, it abuts against the anchor 3a located inside the cavity and pushes the anchor 3a to move outward from the shell 3c. The present invention facilitates the movement of the anchor 3a due to the expansion of the bladder 3d by providing the second guide slope. In other embodiments, as described above, a first guide slope can also be provided on the anchor 3a.

[0056] In summary, the intramedullary nail and intramedullary nail kit of the present invention, by adjusting the transformation of the internal fixation component and the spiral component between martensite and austenite phases through a cold source, gives the intramedullary nail the advantages of easy implantation and good fixation effect, while possessing the fixation effect of both intramedullary nails and metal cables. The handheld device 4 facilitates the operator's insertion of the intramedullary nail into the human body. The grooved design of the mating part reduces the volume of the intramedullary nail after mating with the handheld device 4. The first and second channels facilitate continuous heat exchange between the internal fixation component 1 and the spiral component 2 and the cold source. The breaking component 3 systematically breaks down substances such as yellow bone marrow that obstruct the advancement of the internal fixation component 1 within the medullary cavity, reducing damage to the medullary cavity. The fluid pump facilitates convenient control of the movement of the anchor 3a and the breaking component 3b. The control module and driver 5 effectively control the automatic movement of the internal fixation component 1 within the medullary cavity. The housing 3c effectively protects the fluid drive components and facilitates the entry of the breaking component 3 into the medullary cavity. The design of the capsule 3d simplifies the structure of the breaking component 3, making it easy to manufacture. The return spring allows the breaking component 3b to automatically retract during the movement of the inner fixing component 1. The second guide ramp facilitates the movement of the anchor 3a due to the expansion of the capsule 3d.

[0057] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An intramedullary nail, characterized in that, It includes a strip-shaped internal fixation member (1) and a spiral member (2) arranged around the internal fixation member (1). The first end of the spiral member (2) is connected to one end of the internal fixation member (1), and the second end of the spiral member (2) extends out of the spiral member (2). There is a gap between the internal fixation member (1) and the spiral member (2). Both the internal fixation member (1) and the spiral member (2) are made of shape memory alloy. The spiral member (2) is configured such that its diameter decreases during the transformation from martensitic phase to austenitic phase. The internal fixation member (1) is configured such that its hardness increases during the transformation from martensitic phase to austenitic phase.

2. The intramedullary nail according to claim 1, characterized in that, The internal fixation member (1) has a first channel extending to the outer surface of the internal fixation member (1) away from the end of the spiral member (2); the spiral member (2) has a second channel communicating with the first channel extending to the outer surface of the spiral member (2) away from the end of the internal fixation member (1); the first channel and the second channel are configured to allow fluid to pass through.

3. The intramedullary nail according to claim 2, characterized in that, The inner fixing member (1) is provided with a breaking component (3) at one end away from the spiral member (2); the breaking component (3) includes an anchor (3a), a breaking component (3b), a fluid driving component, and a connector connecting the anchor (3a) and the breaking component (3b), and the fluid driving component is in communication with the first channel; The anchor (3a) is configured to be displaced in a direction away from the axis of the inner fastener (1); The breaking member (3b) is configured to be displaced along the axis of the inner fixation member (1) and away from the inner fixation member (1); The fluid drive component is configured to drive the anchor (3a) to generate displacement and maintain the displacement amount, and subsequently drive the breaker (3b) to generate displacement.

4. The intramedullary nail according to claim 3, characterized in that, The connector is a housing (3c) with a cavity. The housing (3c) has a first through hole for accommodating the anchor (3a) and a second through hole for accommodating the breaker (3b). Both the first through hole and the second through hole are connected to the cavity. One end of the anchor (3a) and the breaker (3b) are located inside the cavity. The fluid drive component is located inside the cavity. The anchor (3a) and the breaker (3b) are displaced to their extreme positions by the fluid drive component. The ends of both the anchor (3a) and the breaker (3b) that are away from the cavity are located on the outer side of the outer surface of the housing (3c).

5. The intramedullary nail according to claim 4, characterized in that, The fluid-driven component is a bladder (3d) that expands after fluid is introduced. The bladder (3d) is connected to the first channel. The bladder (3d) has a contracted state and is located on the side of the anchor (3a) facing the inner fixing member (1). The bladder (3d) in the contracted state is configured to expand toward the breaking member (3b). The expanded bladder (3d) drives the anchor (3a) and the breaking member (3b) to produce displacement.

6. The intramedullary nail according to claim 4, characterized in that, A return spring is connected between the breaking member (3b) located in the cavity and the inner wall of the cavity for driving the breaking member (3b) to move toward the inner fixing member (1).

7. An intramedullary nail kit, characterized in that, Includes a cold source and an intramedullary nail as described in any one of claims 3 to 6, wherein the cold source is configured such that its temperature is lower than a preset temperature setting, the cold source exchanges heat with both the internal fixation member (1) and the spiral member (2), and both the internal fixation member (1) and the spiral member (2) are in the martensitic phase.

8. The intramedullary nail kit according to claim 7, characterized in that, It also includes a columnar handpiece (4) with a mating portion on its surface that supports the inner fixing member (1). The mating portion is configured such that the inner fixing member (1) slides within the mating portion along the axial direction of the handpiece (4) and the inner fixing member (1) can slide out of the mating portion. The spiral member (2) is wound around the outer wall of the handpiece (4), and at least a portion of the body of the handpiece (4) is accommodated in the gap between the inner fixing member (1) and the spiral member (2).

9. The intramedullary nail kit according to claim 8, characterized in that, It also includes a fluid pump, which is connected to the second channel, and the cold source is a coolant that flows in the first channel and the second channel driven by the fluid pump.

10. The intramedullary nail kit according to claim 9, characterized in that, It also includes a control module and a driver (5) disposed on the handheld device (4), the driver (5) being configured to drive the inner fixing member (1) to slide within the mating part; the control module being configured to selectively and independently trigger the driver (5) or the fluid pump to work, and to achieve alternating operation of the two.

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