Assembled extensible intramedullary nail
The modular, extendable intramedullary nail design allows for detachable connection of the mother and daughter nails and offers diverse locking components, solving the problems of multiple production specifications and inconvenient storage in existing technologies, thus achieving efficient production and storage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEBEI RUIHE MEDICAL DEVICES CO LTD
- Filing Date
- 2025-03-24
- Publication Date
- 2026-05-01
AI Technical Summary
Existing extendable intramedullary nails require various sizes, which makes production difficult and storage inconvenient.
It adopts an assembly-type design, with the female and female screws being detachably connected. The locking components are available in various models and can be assembled according to patient data, reducing the number of production specifications.
It improves production efficiency, facilitates storage, and adapts to the individual needs of different patients.
Smart Images
Figure CN224179779U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of medical device technology, specifically relating to an assembled extendable intramedullary nail. Background Technology
[0002] Osteogenesis imperfecta, also known as brittle bone disease or "porcelain doll" in young children, is characterized by severe fractures from even minor impacts. Treatment with intramedullary nails is challenging due to the specific nature of this condition. The nail, implanted in the long bone, needs to remain in the medullary cavity for an extended period to prevent angular deformities and refracture. However, as children grow, the overall bone length increases, the intramedullary nail shortens relatively, and its tail gradually moves away from the metaphysis. This leads to the loss of protection from the nail on the distal end, resulting in localized deformation and angular deformities, ultimately leading to an inevitable fracture at the junction of the nail's tail and the bone. Therefore, standard intramedullary nails designed for adults are unsuitable for the characteristics of children's bone growth and cannot meet their specific needs. In the treatment of brittle bone disease, extended intramedullary nails are used to treat osteogenesis imperfecta, tibial pseudoarthrosis, and other skeletal deformities in children. Lengthening intramedullary nails are commonly used in orthopedic reconstructive surgery. They are implantable metal medical devices used in patients with low bone mass or bone deformities (such as severe osteoporosis, osteogenesis imperfecta, rickets, etc.), and are particularly suitable for children and adolescents whose bodies are still developing and whose long bones are continuously growing. Using lengthening intramedullary nails can effectively reduce the number of revision surgeries required in this age group. Lengthening intramedullary nails are generally made of medical-grade steel. During use, they are installed into the medullary cavity of the long bones of the patient's limbs through osteotomy. They can be implanted into the medullary cavities of the humerus, ulna, and radius in the upper limbs, and the femur, tibia, and fibula in the lower limbs, thereby strengthening the long bones of the limbs to withstand lateral impacts and reducing the risk of fractures. Current lengthening intramedullary nails generally consist of a mother nail and an inner nail. The mother nail is a long cylindrical shape, and the inner nail is a long cylindrical rod shape. The inner nail is inserted inside the mother nail and can rotate or move vertically within the mother nail. After the extensionable intramedullary nail is implanted in the patient, the daughter nail is fixed to the distal epiphysis of the long bone. The interlocking and friction between the threads and the epiphysis ensures the distal end of the daughter nail is fixed within the epiphysis. Therefore, the daughter nail moves distally as the growth plate grows. The mother nail is fixed to the proximal epiphysis of the same long bone. Since long bones develop and grow through continuous proliferation and calcification of the distal and proximal growth plates, and the daughter and mother nails are fixed to the proximal and distal epiphysis of the long bone respectively, as the long bone develops, the daughter and mother nails will move distally and proximally respectively, reducing the overlap between them and maintaining internal fixation and stability throughout the long bone. Because the daughter nail is inserted within the mother nail, and the daughter and mother nails have a considerable overlap area, the extensionable intramedullary nail can still provide a certain degree of lateral impact protection for a considerable period after implantation. Currently, the extendable intramedullary nails used in clinical practice need to be available in various sizes to meet different patient needs, which increases the difficulty of production and requires a lot of storage space. Utility Model Content
[0003] The purpose of this invention is to provide an assemblable extendable intramedullary nail, which aims to solve the problems of extendable intramedullary nails needing to have multiple specifications and sizes, being difficult to produce, and being difficult to store.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An assemblable extendable intramedullary nail is provided, comprising a mother nail, a daughter nail, and a locking element. The mother nail is cylindrical, and the daughter nail is rod-shaped. The daughter nail passes through the mother nail, with its proximal end located within the mother nail and its distal end extending out of the mother nail. The locking element is disposed at the proximal end of the mother nail and is either a threaded head or a locking cylinder.
[0005] In one possible implementation, the distal end of the sub-pin is provided with a first locking pin hole.
[0006] In one possible implementation, the distal end of the sub-nail is provided with a helical nail head.
[0007] In one possible implementation, the spiral nail head includes a mounting cylinder and a spiral nail portion, the mounting cylinder being sleeved on the distal end of the sub-nail, and the spiral nail portion being disposed at the distal end of the mounting cylinder.
[0008] In one possible implementation, the sub-nails and the spiral nail head are integrally formed components.
[0009] In one possible implementation, the side wall of the mounting cylinder is provided with a second locking pin hole, which matches the first locking pin hole. A locking strip is inserted into both the first and second locking pin holes, and one end of the locking strip is threadedly connected to the second locking pin hole.
[0010] In one possible implementation, the female pin and the threaded head are integrally formed components.
[0011] In one possible implementation, the threaded head is threaded to the proximal end of the female pin.
[0012] In one possible implementation, the female pin and the locking cylinder are integrally formed components, and the side wall of the locking cylinder is provided with an upper locking pin hole.
[0013] In one possible implementation, the locking cylinder is threaded to the proximal end of the female pin.
[0014] The beneficial effects of the assembled extendable intramedullary nail provided by this utility model are as follows:
[0015] Compared with existing technologies, this device includes a mother nail, a daughter nail, and a locking element. The mother nail is cylindrical with a central through-hole. The daughter nail is rod-shaped and passes through the central through-hole of the mother nail, with its proximal end inside the through-hole and its distal end protruding from the mother nail and located below the distal end. The locking element is located at the proximal end of the mother nail and can have various models and specifications, including threaded heads and locking sleeves. Both the mother nail and daughter nail can be selected based on the patient's body data and actual needs. The mother nail and daughter nail are assembled and then implanted into the patient. The mother nail and daughter nail are detachably connected. One model of mother nail can match multiple models and specifications of daughter nails, and vice versa. This reduces the number of intramedullary nails that need to be produced, improves production efficiency, and facilitates storage. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 Three-dimensional structural schematic diagrams of four embodiments of the assembled extendable intramedullary nail provided for the present utility model;
[0018] Figure 2 This is a schematic diagram of the vertical cross-sectional structure of the threaded head used in the embodiment of this utility model;
[0019] Figure 3 This is a schematic diagram of the vertical cross-sectional structure of the locking cylinder used in the embodiment of this utility model;
[0020] Figure 4 This is an exploded structural diagram of the sub-nails and spiral nail heads used in an embodiment of this utility model.
[0021] In the figure: 100, female nail; 101, proximal end; 102, connecting part; 103, main body; 104, central through hole; 105, second guide surface; 200, female nail; 201, implant tip; 202, first guide surface; 203, first locking nail hole; 300, spiral nail head; 301, mounting cylinder part; 302, spiral nail part; 303, second locking nail hole; 400, locking bar; 401, first rotating groove; 500, threaded head; 501, first fixed threaded post; 502, second fixed threaded post; 503, second rotating groove; 600, locking cylinder; 601, upper locking nail hole; 602, fixing slot; 603, third fixed threaded post. Detailed Implementation
[0022] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0023] Please refer to Figures 1 to 3 The present invention provides a specific embodiment of an assembled extendable intramedullary nail, comprising a mother nail 100, a daughter nail 200, and a locking member. The mother nail 100 is cylindrical, and the daughter nail 200 is rod-shaped. The daughter nail 200 is inserted into the mother nail 100, with its proximal end located inside the mother nail 100 and its distal end protruding from the mother nail 100. The locking member is located at the proximal end of the mother nail 100 and is either a threaded head 500 or a locking cylinder 600.
[0024] This utility model provides an assemblable extendable intramedullary nail. Compared with the prior art, it includes a female nail 100, a female nail 200, and a locking element. The female nail 100 is cylindrical with a central through hole 104. The female nail 200 is rod-shaped and passes through the central through hole 104 of the female nail 100. The proximal end of the female nail 200 is located within the central through hole 104, and the distal end of the female nail 200 protrudes from the female nail 100 and is located below the distal end of the female nail 100. The locking element is located at the proximal end of the female nail 100. The locking element can have various models and specifications, and can be a threaded head 500 or a lock. The fixed tube 600 and the mother nail 100 are available in various models and specifications, and the daughter nail 200 can also be available in various specifications. The model and specifications of the mother nail 100 and daughter nail 200 are selected according to the patient's body data and actual needs. The mother nail 100 and daughter nail 200 are assembled and then implanted into the patient's body. The mother nail 100 and daughter nail 200 are detachably connected. One model of mother nail 100 can be matched with multiple models and specifications of daughter nail 200, and one model of daughter nail 200 can be matched with multiple models and specifications of mother nail 100. This can reduce the number of specifications and models of intramedullary nails that need to be produced, improve production efficiency, and facilitate storage.
[0025] For details, please refer to Figures 1 to 3It includes a female nail 100, a male nail 200, and a locking element. The female nail 100 is cylindrical, and the male nail 200 is rod-shaped. A central through hole 104 is provided in the center of the female nail 100, extending along its length. The central through hole 104 is suitable for the insertion of the male nail 200. The proximal end of the male nail 200 passes through the central through hole 104 and is slidably disposed within it. The male nail 200 has the freedom to slide along the length of the female nail 100, and the distal end of the male nail 200 extends beyond the distal end of the female nail 100. The distal end is located below the distal end of the female nail 100. The female nail 100 includes a proximal end portion 101, a connecting portion 102, and a main body portion 103. The proximal end portion 101, the connecting portion 102, and the main body portion 103 are sequentially connected. The proximal end portion 101 is located at the proximal end of the female nail 100, and the diameter of the proximal end portion 101 is larger than the diameter of the main body portion 103. The connecting portion 102 connects the proximal end portion 101 and the main body portion 103, and the diameter of the connecting portion 102 gradually decreases as it approaches the main body portion 103. The distal end of the female nail 200 is provided with an implantation tip 201 for easy implantation. The side of the female nail 200... The wall is provided with a first guide surface 202, which is arranged along the length direction of the male nail 200. A second guide surface 105 is provided on the inner wall of the central through hole 104, which is also arranged along the length direction of the central through hole 104. The first guide surface 202 and the second guide surface 105 match, and under the action of the first guide surface 202 and the second guide surface 105, no relative rotation occurs between the male nail 200 and the female nail 100, increasing the stability of the device. A locking element is provided on the proximal end 101 of the female nail 100. The locking element can have various models. Specifications: The locking element is either a threaded head 500 or a locking sleeve 600. The female nail 100 can have multiple models and specifications, and the female nail 200 can have multiple specifications. One model and specification of female nail 100 can be matched with multiple models of threaded heads 500 or multiple models of locking sleeves 600. The model and specifications of female nail 100 and female nail 200 are selected according to the patient's body data and actual needs. The female nail 100 and female nail 200 are assembled and implanted into the patient's body. This can reduce the number of specifications and models of intramedullary nails that need to be produced, improve production efficiency, and facilitate storage.
[0026] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figures 1 to 4 The distal end of the nail 200 is provided with a first locking nail hole 203.
[0027] For details, please refer to Figures 1 to 4 The first locking pin hole 203 is located at the distal end of the sub-pin 200. The first locking pin hole is set through the left and right side walls of the sub-pin 200. The first locking pin is inserted through the first locking pin hole and is used to fix the distal end of the sub-pin 200 in the patient's body.
[0028] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figures 1 to 4 The distal end of the nail 200 is provided with a spiral nail head 300.
[0029] For details, please refer to Figures 1 to 4 The spiral screw head 300 is located at the distal end of the sub-screw 200, and the spiral screw head 300 helps to enhance the stability of the device in the patient's body.
[0030] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figures 1 to 4 The spiral nail head 300 includes a mounting cylinder 301 and a spiral nail 302. The mounting cylinder 301 is sleeved on the distal end of the sub-nail 200, and the spiral nail 302 is disposed on the distal end of the mounting cylinder 301.
[0031] For details, please refer to Figures 1 to 4 The spiral nail head 300 includes a mounting cylinder 301 and a spiral nail 302. The spiral nail 302 is disposed at the distal end of the mounting cylinder 301. The proximal end of the mounting cylinder 301 has an upper opening. The mounting cylinder 301 is sleeved on the distal end of the sub-nail 200. The spiral nail 302 is suitable for implantation into the patient's bone and helps to enhance the stability of the device in the patient's body.
[0032] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figures 1 to 4 The stub 200 and the spiral stub head 300 are integrally formed components.
[0033] For details, please refer to Figures 1 to 4 The sub-nails 200 and the spiral nail head 300 are made using an integral molding process, and can be made using welding, casting, 3D printing or other processes, which increases the stability of the connection between the sub-nails 200 and the spiral nail head 300.
[0034] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figures 1 to 4 The side wall of the mounting cylinder 301 is provided with a second locking pin hole 303, which matches the first locking pin hole 203. A locking strip 400 is inserted into the first locking pin hole 203 and the second locking pin hole 303, and one end of the locking strip 400 is threadedly connected to the second locking pin hole.
[0035] For details, please refer to Figures 1 to 4The sub-nails 200 and the spiral nail head 300 are detachably connected. The second locking nail holes 303 are located on the side wall of the mounting cylinder 301. Two sets of second locking nail holes 303 are correspondingly located on the left and right side walls of the mounting cylinder 301. The second locking nail holes 303 match the first locking nail holes 203. The locking strip 400 sequentially passes through the first second locking nail hole 303, the first locking nail hole 203, and the second second locking nail hole 303, locking the mounting cylinder 301 to the distal end of the sub-nails 200. This adds a device that... To ensure stability, the locking bar 400 is cylindrical, facilitating its insertion. The first end of the locking bar 400 has a threaded portion, and a set of second locking pin holes has threads inside that match the threaded portion of the locking bar 400, allowing the locking bar 400 to lock the spiral pin head 300, thus increasing the stability of the device. The center of the second end of the locking bar 400 has a first rotating groove 401, which is an internal hexagonal groove, facilitating the rotation of the locking bar 400 by surgical instruments.
[0036] Furthermore, the selection can be made according to the patient's actual situation. One-piece molded sub-screws 200 and spiral screw heads 300 can be selected, or detachable sub-screws 200 and spiral screw heads 300 can be selected. The need for spiral screw heads 300 can be determined based on the actual situation. If spiral screw heads 300 are required, the model and specifications of the spiral screw head 300 can be selected based on the patient's actual body data. One specification of sub-screw 200 can be matched with multiple models and specifications of spiral screw heads 300, reducing the number of sub-screw 200 models and specifications that need to be produced, improving production efficiency, and facilitating storage.
[0037] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figure 1 as well as Figure 2 The female nail 100 and the threaded head 500 are integrally formed components.
[0038] For details, please refer to Figure 1 as well as Figure 2 The locking element can be a threaded head 500, which is located at the proximal end of the female nail 100. The female nail 100 and the threaded head 500 are made by an integral molding process, which can be made by welding, casting, 3D printing or other processes to increase the stability of the connection between the female nail 100 and the threaded head 500. The outer wall of the threaded head 500 is provided with locking threads, which is suitable for midshaft fractures.
[0039] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figure 1 as well as Figure 2 The threaded head 500 is connected to the proximal thread of the female pin 100.
[0040] For details, please refer to Figure 1 as well as Figure 2 The threaded head 500 is detachably connected to the female nail 100. The outer wall of the threaded head 500 is provided with locking threads. The distal end of the threaded head 500 is provided with a first fixed threaded post 501. The first fixed threaded post 501 and the proximal end of the female nail 100 are threaded together. The proximal end of the threaded head 500 is provided with a second fixed threaded post 502. The diameter of the threaded head 500 is larger than the diameter of the first fixed threaded post 501 and the diameter of the second fixed threaded post 502. The center of the proximal end of the second fixed threaded post 502 is provided with a second rotating groove 503. The second rotating groove 503 is an internal hexagonal groove to facilitate the rotation of the threaded head 500 by surgical instruments.
[0041] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figure 1 as well as Figure 3 The female nail 100 and the locking cylinder 600 are integrally formed components. The locking component is the locking cylinder 600, and the side wall of the locking cylinder 600 is provided with an upper locking nail hole 601.
[0042] For details, please refer to Figure 1 as well as Figure 3 The locking element can be a locking cylinder 600, which is located at the proximal end of the mother nail 100. The mother nail 100 and the locking cylinder 600 are made by an integral molding process, which can be made by welding, casting, 3D printing or other processes to increase the stability of the connection between the mother nail 100 and the locking cylinder 600. The side wall of the locking cylinder 600 is provided with an upper locking nail hole 601, in which a proximal locking nail can be inserted. It is suitable for mid-shaft and / or proximal and distal fractures, or for patients with osteoporosis. The locking cylinder 600 and the proximal locking nail are used to fix the proximal end of the patient's bone.
[0043] As a specific embodiment of the assembled extendable intramedullary nail provided by this utility model, please refer to Figure 1 as well as Figure 3 The locking cylinder 600 is threaded to the near end of the female nail 100.
[0044] For details, please refer to Figure 1 as well as Figure 3 The locking cylinder 600 is detachably connected to the female nail 100. The side wall of the locking cylinder 600 is provided with an upper locking nail hole 601. The distal end of the locking cylinder 600 is provided with a third fixing threaded post 603. The third fixing threaded post 603 and the proximal end of the female nail 100 are threaded together. The proximal end of the locking cylinder 600 is provided with a threaded groove, which is suitable for the installation of the device. The side wall of the proximal end of the threaded groove is provided with a fixing slot 602, which facilitates the fixation of surgical instruments.
[0045] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An assembled extendable intramedullary nail, characterized in that, It includes a female nail, a male nail, and a locking element. The female nail is cylindrical, and the male nail is rod-shaped. The male nail passes through the female nail, with its proximal end inside the female nail and its distal end protruding from the female nail. The locking element is located at the proximal end of the female nail and is a threaded head or a locking cylinder.
2. The assembled extendable intramedullary nail as described in claim 1, characterized in that, The distal end of the sub-nail is provided with a first locking nail hole.
3. The assembled extendable intramedullary nail as described in claim 2, characterized in that, The distal end of the sub-nail is provided with a spiral nail head.
4. The assembled extendable intramedullary nail as described in claim 3, characterized in that, The spiral nail head includes a mounting cylinder and a spiral nail. The mounting cylinder is sleeved on the distal end of the sub-nail, and the spiral nail is located at the distal end of the mounting cylinder.
5. An assembly type extendable intramedullary nail as claimed in claim 4, characterized in that The sub-nail and the spiral nail head are integrally formed components.
6. An assembly type extendable intramedullary nail as claimed in claim 4, wherein, The side wall of the mounting cylinder is provided with a second locking pin hole, which matches the first locking pin hole. A locking strip is inserted into the first locking pin hole and the second locking pin hole, and one end of the locking strip is threadedly connected to the second locking pin hole.
7. An assembly type extendable intramedullary nail as defined in claim 1, characterized in that The female pin and the threaded head are integrally formed components.
8. An assembly type extendable intramedullary nail as defined in claim 1, characterized in that The threaded head is threadedly connected to the proximal end of the female nail.
9. An assembly type extendable intramedullary nail as in claim 1, wherein, The female nail and the locking cylinder are integrally formed components, and the side wall of the locking cylinder is provided with an upper locking nail hole.
10. The assembled extendable intramedullary nail as described in claim 1, characterized in that, The locking cylinder is threaded to the proximal end of the female nail.