Adjustable intramedullary nail system with electromagnetic healing promoting function and mounting method

Abstract

The invention relates to an adjustable intramedullary nail system with an electromagnetic healing promoting function, the intramedullary nail system comprises a main nail, a fixing hole is formed in the tail end of the main nail, an electromagnetic device is fixed in the fixing hole in the main nail, the electromagnetic device is provided with an adjusting device, and the adjusting device adjusts the position of a bone fracture according to the position of the bone fracture and the distance of the electromagnetic device. Adjusting magnetic field parameters of the electromagnetic device through mechanical adjustment; the electromagnetic device can generate a pulsed magnetic field to promote fracture healing. According to the adjustable intramedullary nail system with the electromagnetic healing promoting function, the electromagnetic device is fixed to the main nail, the distance between the electromagnetic device and a fracture / healing position is reduced, the distance corresponds to the magnetic field intensity generated by the electromagnetic device in a one-to-one mode, application of the device has universality, and operation adjustment is simplified.

Description

Technical Field

[0001] The present invention relates to medical surgical instruments, and particularly to an adjustable intramedullary nail system with electromagnetic bone healing promotion function. Background Art

[0002] Due to varying degrees of osteoporosis in elderly patients, minor trauma or falls can lead to hip fractures, including femoral neck fractures, intertrochanteric fractures of the femur, etc. Therefore, hip fractures are common fracture sites in the elderly, and the commonly used internal fixation is locked intramedullary nail fixation. However, the existing intramedullary nail fracture surgery has a long healing period and a high delayed healing rate. Approximately 10% of fractures are delayed in healing due to insufficient blood supply, poor fixation stability, or abnormal patient metabolism (such as diabetes). Conventional intramedullary nails only provide mechanical fixation and lack the bioactive function of promoting bone regeneration. For example, the prior arts CN215192132U and CN113925587A disclose a proximal femoral triangular intramedullary nail, which uses a main nail, a first locking nail, and a second locking nail to form a triangular structure to achieve the stability of the screws in the femoral head and neck. This intramedullary nail only maintains the stability of the fracture end through mechanical fixation and cannot actively promote callus formation and mineralization, and has limited effects on delayed healing cases.

[0003] Research has shown that electromagnetic fields have a significant function in promoting bone healing. Existing technologies (see "Pulsed Electromagnetic Field Stimulation of Bone Healing and Joint Preservation: Cellular Mechanisms of Skeletal Response" in 《JAAOS Global Research & Reviews》2020, Volume 4, authors: Ruggero Cadossi, MD, etc.) have found that pulsed (60Hz) electromagnetic fields of a certain intensity promote osteogenesis and chondrogenic differentiation by activating A2A and A3 adenosine receptors on the cell membrane, and have the effect of promoting bone healing. The magnetic field intensity of 0.1mt has the best effect on chondrogenesis. In animal model studies, it was found that magnetic fields can accelerate fracture healing and increase trabecular bone density; clinical studies have shown that the non-union healing rate reaches 73%-85%. However, existing electromagnetic therapy technologies have great limitations. Most of them are external electromagnetic devices (such as magnetic patches, pulsed electromagnetic field instruments). For example, the magnetic conduction bone reduction device disclosed in the prior art CN116688364A fixes the magnetic field source coil at the fracture repair site to achieve the purpose of bone reduction. This device is used for bone reduction, belonging to an external device with poor portability and large energy loss, and it is difficult to accurately act on the fracture site; the prior art CN208145052U discloses an intramedullary nail device with an adjustable magnetized part, in which a magnetization rod is arranged on the intramedullary nail to guide magnetized stem cells to the bone defect site to promote bone healing. This technology uses a fixed magnetic field to attract magnetized stem cells to the bone defect site. Although it can promote bone healing, the use of implanted stem cells has a high surgical cost and is not suitable for large-scale promotion; the prior art CN113677395A relates to an electromagnetic field generator that uses an electromagnetic generator arranged in an anchor to generate pulsed electromagnetic fields to promote tendon healing. However, the magnetic field intensity of this device cannot be adjusted with distance, or a fixed magnetic field intensity is preset in advance through relevant operating equipment. Since the anchor is attached to the bone through soft tissues, the position of the anchor cannot be determined before implantation. At the same time, there are also significant differences in the injury positions of each patient. Therefore, the healing position relative to the position of the anchor is not accurately determined, and this distance varies within a large range for different patients. How to conveniently ensure the magnetic field intensity at the healing position when implanting this anchor has become a difficult problem in the current treatment process.

[0004] Therefore, in the related fracture healing methods in the prior art, patient compliance is low, and the magnetic field penetration depth is limited. The energy attenuation results in insufficient magnetic field intensity actually received at the fracture end; the magnetic field parameter intensity lacks standardization with distance, and the clinical effect is unstable. Summary of the Invention

[0005] In order to overcome the deficiencies of the intramedullary nail internal fixation technology in the prior art, the present invention proposes an adjustable intramedullary nail system with electromagnetic healing promotion function. The intramedullary nail system includes a main nail, a fixing hole is provided at the tail end of the main nail, and an electromagnetic device fixed in the fixing hole on the main nail. The electromagnetic device has an adjusting device, and the adjusting device adjusts the magnetic field parameters of the electromagnetic device through mechanical adjustment according to the distance between the fracture position and the electromagnetic device; the mechanical adjustment method can be a convenient adjustment method such as a knob or a roller. The electromagnetic device generates a pulsed magnetic field according to the distance to promote the differentiation of bone and cartilage and improve the fracture healing efficiency. Since the position of the main nail is usually set in the bone marrow cavity and its position is usually relatively fixed, and the electromagnetic device is fixed on the main nail to realize the relative fixation of the position of the electromagnetic device for different patients. And the human femoral head has a definite positional relationship with the femoral body. The height of the femoral head of different populations is usually 2.8-3.2 cm, and the fracture line of the femoral head usually distributes along the femoral neck of the femoral head. Therefore, the relative distance between the fracture position of different populations and a certain point of the main nail is usually within a relatively small range. Therefore, according to the fracture position and the fixed position of the electromagnetic device, the distance between the two and the magnetic field strength generated by the electromagnetic device are made to correspond one by one, so that the application of this device has universality. When performing the corresponding implantation operation, only need to finely adjust the adjusting device to complete the adjustment operation; the selected fracture position is the midpoint of the fracture line. By determining the distance from the midpoint of the fracture line to the electromagnetic device, this distance can be obtained by measuring the straight-line distance between the midpoint of the fracture line and the marking point on the electromagnetic device under X-ray; by fixing the electromagnetic device on the main nail, the distance between the electromagnetic device and the fracture / healing position is reduced, and the magnetic field strength can be accurately adjusted according to the distance, making the adjustment of the implanted electromagnetic device simple and convenient and reducing the operation difficulty during the operation.

[0006] Further preferably, the magnetic field parameter is the magnetic field strength, preferably the magnetic field strength has a range of 0.05 mt - 0.2 mt at the fracture position to promote the healing of the fracture position; in other alternative embodiments, the magnetic field parameter can also be the magnetic field pulse frequency.

[0007] Preferably, the electromagnetic device is fixed at the tail end of the main nail. A fixing hole is provided on the tail end, and the electromagnetic device is installed in the fixing hole. The electromagnetic device can be installed in the fixing hole by threading, bonding or clamping. The tail end of the main nail is usually close to the fracture position and no other components such as interlocking nails are provided. Setting the electromagnetic device at the tail end of the main nail further reduces the distance between the electromagnetic device and the fracture position.

[0008] Preferably, the electromagnetic device has a shape similar to a bolt, including a head and a rod body. Both the head and the rod body are hollow structures. The control circuit and the power supply components are arranged inside the head; the magnetic core and the inner coil are arranged inside the rod body. Since the position of the rod body is close to the midpoint of the fracture line, arranging the inner coil inside the rod body can reduce the operating power of the electromagnetic device and increase its operating time. Further, the magnetic core is an iron core or a soft magnetic core, which can better concentrate the magnetic field and increase the magnetic field generation efficiency.

[0009] Preferably, an opening is formed at one end of the head away from the rod body, and an adjusting device is hermetically installed at the opening; the adjusting device includes an outer knob and an inner knob. The outer knob is detachably and hermetically connected to the opening, and the inner knob can rotate relative to the outer knob to adjust the current magnitude of the inner coil. For example, by arranging an adjusting resistor or other forms of circuits or components for adjusting the current magnitude on the control circuit, the magnitude of the current is changed by rotating the inner knob to adjust the magnetic field strength of the electromagnetic device, so that the fracture position at a specific distance receives the optimal magnetic field strength to promote the healing of the fracture position.

[0010] Preferably, the outer knob is provided with scales for indicating the distance between the fracture position and the electromagnetic device, and an indicating arrow is arranged on the inner knob. According to the distance, by rotating the inner knob, the indicating arrow is directed to the corresponding scale to complete the adjustment of the magnetic field strength. In this application, by corresponding the distance, the magnetic field strength, and the scales one by one, there is no need to calculate the current magnitude of the electromagnetic device again according to the distance. By rotating the inner knob to correspond to the corresponding scale, the adjustment is convenient.

[0011] Preferably, and / or an annular groove is provided on the outer periphery of the main nail corresponding to the position of the rod body, and an outer coil is arranged in the annular groove. Annular electrodes are provided on the main nail and the head of the electromagnetic device. When the electromagnetic device is installed on the main nail, the annular electrodes of the main nail and the electromagnetic device form a circuit for supplying power to the outer coil to generate a magnetic field. Since the material of the main nail is usually a corrosion-resistant metal material such as titanium alloy or stainless steel, it has a certain attenuation effect on the magnetic field of the inner coil arranged inside it. Therefore, an outer coil is arranged on the outer periphery of the main nail to further reduce the distance from the fracture position to the electromagnetic device, and at the same time form a non-attenuating magnetic field, reducing the power of the electromagnetic device. It is more beneficial to promote the healing of the fracture and the magnetic field generation time of the electromagnetic device.

[0012] Preferably, the annular groove is provided with a protective cover for protecting the outer coil from corrosion. Specifically, the protective cover can be peek or other non-metallic materials with low attenuation to the electromagnetic field.

[0013] The present invention also relates to a method for installing an intramedullary nail system. The intramedullary nail system includes a main nail and an electromagnetic device, and the electromagnetic device has an adjusting device. The installation method includes determining the distance between the fracture line and the electromagnetic device, then operating the knob of the adjusting device according to the distance to complete the adjustment, and then completing the postoperative suture. The distance can be obtained by measuring the straight-line distance between the midpoint of the fracture line and the marking point on the electromagnetic device under X-ray; adjusting to the optimal magnetic field strength through the adjusting device to promote the healing of the fracture position.

[0014] The present invention aims to provide an intramedullary nail system with an adjustable electromagnetic healing-promoting function and an installation method. By fixing an electromagnetic device on the main nail of the intramedullary nail, and according to the distance between the electromagnetic device and the fracture line, adjusting the magnetic field strength of the electromagnetic device, so that the electromagnetic device acts precisely on the fracture part. Compared with the external electromagnetic device, the distance of the electromagnetic device is reduced, thereby reducing the power of the electromagnetic device and prolonging the service time. Using the magnetic field of the electromagnetic device to promote fracture healing; according to the distance, realizing precise adjustment of the magnetic field strength, making the adjustment of the implanted electromagnetic device simple and convenient, and reducing the operation difficulty during the operation; according to the fracture position and the fixed position of the electromagnetic device, corresponding the distance between the two and the magnetic field strength generated by the electromagnetic device one by one, making the application of this device universal. When performing the corresponding implantation operation, only need to finely adjust the adjusting device to complete the adjustment operation. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of the adjustable electromagnetic healing-promoting function intramedullary nail system of the present application; Figure 2 It is a schematic diagram of the distance between the electromagnetic device and the fracture position of the present application; Figure 3 It is a schematic structural diagram of the electromagnetic device of the present application; Figure 4 It is another schematic structural diagram of the electromagnetic device of the present application; Figure 5 It is a schematic diagram of another embodiment of the intramedullary nail system of the present application.

[0016] Description of the Reference Numerals: 1 - Main nail, 11 - Annular groove, 111 - Outer coil, 12 - First annular electrode, 13 - Fixing hole, 2 - Electromagnetic device, 21 - Head, 211 - Control circuit, 212 - Power supply component, 213 - Second annular electrode, 22 - Rod body, 221 - Magnetic core, 222 - Inner coil, 23 - Knob outer ring, 24 - Knob inner wheel. Detailed Embodiments

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] To make the drawings concise, only the parts related to the present invention are schematically shown in each drawing, and they do not represent the actual structure of the product. Additionally, to make the drawings concise and easy to understand, in some drawings, components with the same structure or function are only schematically shown for one of them, or only one of them is marked. In this article, "one" not only means "only this one", but also can mean "more than one" situation.

[0019] It should also be further understood that the term "and / or" used in the specification and appended claims of this application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0020] In this article, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In order to overcome the deficiencies of the intramedullary nail internal fixation technology in the prior art, the present invention proposes an adjustable intramedullary nail system with electromagnetic healing promotion function. The intramedullary nail system includes a main nail 1 and an electromagnetic device 2 fixed on the main nail 1. The electromagnetic device 2 has an adjustment device, and the adjustment device adjusts the magnetic field parameters of the electromagnetic device 2 through mechanical adjustment according to the distance between the fracture position and the electromagnetic device 2; the mechanical adjustment method can be a convenient adjustment method such as a knob or a roller. The electromagnetic device 2 generates a pulsed magnetic field according to the distance to promote the differentiation of bone and cartilage and improve the fracture healing efficiency. Since the position of the main nail 1 is usually set in the bone marrow cavity and its position is usually relatively fixed, and the electromagnetic device 2 is fixed on the main nail 1 to realize the relative fixation of the position of the electromagnetic device 2 for different patients. The femoral head of the human body has a definite positional relationship with the femoral body. The height of the femoral head of different populations is usually 2.8 - 3.2 cm, and the fracture line of the femoral head usually distributes along the femoral neck of the femoral head. Therefore, the relative distance between the fracture position of different populations and a certain point of the main nail 1 is usually within a relatively small range. Therefore, according to the fracture position and the fixed position of the electromagnetic device 2, the distance between the two and the magnetic field strength generated by the electromagnetic device 2 are made to correspond one by one, so that the application of this device has universality. When performing the corresponding implantation operation, only need to finely adjust the adjustment device to complete the adjustment operation; the selected fracture position is the midpoint of the fracture line. By determining the distance from the midpoint of the fracture line to the electromagnetic device 2, this distance can be obtained by measuring the straight-line distance between the midpoint of the fracture line and the marking point on the electromagnetic device 2 under X-ray; by fixing the electromagnetic device 2 on the main nail 1, the distance between the electromagnetic device 2 and the fracture / healing position is reduced, and the magnetic field strength can be accurately adjusted according to the distance, making the adjustment of the implanted electromagnetic device 2 simple and convenient and reducing the operation difficulty during the operation.

[0022] Further preferably, the magnetic field parameter is the magnetic field strength, preferably the magnetic field strength has a range of 0.05 mt - 0.2 mt at the fracture position to promote the healing of the fracture position; in other alternative embodiments, the magnetic field parameter can also be the magnetic pulse frequency.

[0023] Preferably, the electromagnetic device 2 is fixed at the tail end of the main nail 1. A fixing hole 13 is provided at the tail end, and the electromagnetic device 2 is installed in the fixing hole 13. The electromagnetic device 2 can be installed in the fixing hole 13 by threading, bonding or clamping. The tail end of the main nail 1 is usually close to the fracture position and no other components such as interlocking nails are provided. Setting the electromagnetic device 2 at the tail end of the main nail 1 further reduces the distance between the electromagnetic device 2 and the fracture position.

[0024] Preferably, the electromagnetic device 2 has a substantially bolt shape, including a head 21 and a rod body 22. Both the head 21 and the rod body 22 are hollow structures. A control circuit 211 and a power supply component 212 are arranged inside the head 21. For example, the power supply component may have a battery for energy storage and / or a wireless charging device; a magnetic core 221 and an inner coil 222 are arranged in the rod body 22. Since the position of the rod body 22 is close to the midpoint of the fracture line, arranging the inner coil 222 in the rod body 22 can reduce the operating power of the electromagnetic device and increase its operating time. Further, the magnetic core 221 is an iron core or a soft magnetic core 221, which can better confine the magnetic field and increase the magnetic field generation efficiency.

[0025] Preferably, an opening is formed at one end of the head 21 away from the rod body 22, and an adjusting device is hermetically installed at the opening; the adjusting device includes an outer knob 23 and an inner knob 24. The outer knob 23 is detachably and hermetically connected to the opening, and the inner knob 24 can rotate relative to the outer knob 23 to adjust the current magnitude of the inner coil 222. For example, by arranging an adjusting resistor or other forms of circuits or components for adjusting the current magnitude on the control circuit 211, the current magnitude is changed by rotating the inner knob 24 to adjust the magnetic field intensity of the electromagnetic device 2, so that the fracture position at a specific distance receives the optimal magnetic field intensity to promote the healing of the fracture position.

[0026] Preferably, the outer knob 23 is provided with scales for indicating the distance between the fracture position and the electromagnetic device 2, and an indicating arrow is arranged on the inner knob 24. According to the distance, by rotating the inner knob 24, the indicating arrow is directed to the corresponding scale to complete the adjustment of the magnetic field intensity. In this application, by corresponding the distance, the magnetic field intensity, and the scales one by one, there is no need to calculate the current magnitude of the electromagnetic device 2 again according to the distance. By rotating the inner knob 24 to the corresponding scale, the adjustment is convenient.

[0027] Preferably, an annular groove 11 is provided on the outer periphery of the main nail 1 corresponding to the position of the rod body 22. An outer coil 111 is arranged in the annular groove 11. A first annular electrode 12 is provided on the main nail 1, and a second annular electrode 213 is provided on the head 21 of the electromagnetic device 2. When the electromagnetic device 2 is installed on the main nail 1, the annular electrodes of the main nail 1 and the electromagnetic device 2 form a circuit for supplying power to the outer coil 111, thereby generating a magnetic field. Since the material of the main nail 1 is usually a corrosion-resistant metal material such as titanium alloy or stainless steel, it has a certain attenuation effect on the magnetic field of the inner coil 222 provided therein. Therefore, an outer coil 111 is provided on the outer periphery of the main nail 1 to further reduce the distance from the fracture position to the electromagnetic device 2, and at the same time form a non-attenuating magnetic field, reducing the power of the electromagnetic device 2. It is more beneficial to promote the healing of fractures and the continuous generation time of the magnetic field of the electromagnetic device 2. Further preferably, the part of the main nail 1 around which the outer coil 111 is wound has a ferromagnetic material, so as to better confine the magnetic field of the outer coil 111 and increase the magnetic field strength at the fracture position. Specifically, a ferromagnetic metal sleeve can be sleeved in the annular groove 11.

[0028] Preferably, the annular groove is provided with a protective cover for protecting the outer coil from corrosion. Specifically, the protective cover can be peek or other non-metallic materials with low attenuation of electromagnetic fields.

[0029] The present invention also relates to a method for installing an intramedullary nail system. The intramedullary nail system includes a main nail 1 and an electromagnetic device 2. The electromagnetic device 2 has an adjusting device. The installation method includes determining the distance between the fracture line and the electromagnetic device 2, then operating the knob inner wheel of the adjusting device to complete the adjustment according to the distance, and then completing the postoperative suture. The distance can be obtained by measuring the straight-line distance between the midpoint of the fracture line and the marking point on the electromagnetic device 2 under X-ray; adjusting to the optimal magnetic field strength through the adjusting device to promote the healing of the fracture position.

Claims

1. An intramedullary nail system with adjustable electromagnetic healing function, the intramedullary nail system comprising a main nail, characterized in that: A fixing hole is provided at the tail end of the main nail, and an electromagnetic device is fixed in the fixing hole on the main nail. The electromagnetic device has an adjustment device, and the adjustment device adjusts the magnetic field parameters of the electromagnetic device through mechanical adjustment according to the distance between the fracture position and the electromagnetic device; the electromagnetic device can generate a pulsed magnetic field to promote fracture healing.

2. The intramedullary nail system with adjustable electromagnetic healing function according to claim 1, characterized in that: The magnetic field parameter is the magnetic field strength, and the magnetic field strength of the electromagnetic device is adjusted by the adjusting device.

3. The intramedullary nail system with adjustable electromagnetic healing function according to claim 1 or 2, characterized in that: The electromagnetic device is installed in the fixing hole by means of thread, bonding, clamping or magnetic adsorption.

4. The intramedullary nail system with adjustable electromagnetic healing function according to claim 1 or 2, characterized in that: The electromagnetic device has a shape of a bolt structure, including a head and a rod body, and both the head and the rod body are hollow structures.

5. The intramedullary nail system with adjustable electromagnetic healing function according to claim 4, characterized in that: It also includes a control circuit, a power supply component, a magnetic core and an inner coil. The control circuit and the power supply component are arranged in the head; the magnetic core and the inner coil are arranged in the rod body.

6. The intramedullary nail system with adjustable electromagnetic healing function according to claim 4, characterized in that: An opening is formed at one end of the head away from the rod body, and an adjustment device is sealed and installed on the opening; the adjustment device includes a knob outer ring and a knob inner wheel, wherein the knob outer ring is detachably sealed and connected to the opening, and the knob inner wheel can be rotated relative to the knob outer ring to adjust the magnetic field strength of the electromagnetic device.

7. The intramedullary nail system with adjustable electromagnetic healing function according to claim 6, characterized in that: The outer ring of the knob is provided with a scale for indicating the distance between the fracture position and the electromagnetic device, and the inner ring of the knob is provided with an indicating arrow.

8. The intramedullary nail system with adjustable electromagnetic healing function according to claim 4, characterized in that: And / or an annular groove is opened on the outer circumference of the main nail corresponding to the position of the rod body, an outer coil is arranged in the annular groove, a first annular electrode is arranged on the main nail, and a second annular electrode is arranged on the head of the electromagnetic device. When the electromagnetic device is installed on the main nail, the first annular electrode of the main nail and the second annular electrode of the electromagnetic device form a passage for supplying power to the outer coil, thereby generating a magnetic field.

9. The intramedullary nail system with adjustable electromagnetic healing function according to claim 8, characterized in that: The annular groove is provided with a protective cover for protecting the outer coil from corrosion.

10. An installation method for an intramedullary nail system according to any one of claims 1-9, wherein the intramedullary nail system comprises a main nail and an electromagnetic device, wherein the electromagnetic device has an adjustment device, and the installation method comprises determining the distance between the fracture line and the electromagnetic device, and then operating the adjustment device to complete the adjustment according to the distance.

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