Resettable anti-rotation implant for femoral neck and femoral intertrochanteric fractures
By designing a repositionable anti-rotation implant with an outer sheath and a pressure-driven rotation axis, the problems of complex operation and insufficient holding force in existing technologies are solved, achieving a simple and quick fracture reduction effect.
Patent Information
- Application Number
- CN202423152913.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2034-12-19
AI Technical Summary
Existing techniques for reducing femoral neck and intertrochanteric fractures are complex to perform, use thin-diameter bone pins, have poor reduction effects, and are difficult to maintain high holding force in the cancellous bone of the femoral head.
A repositionable anti-rotation implant comprising an outer sleeve and a pressure-rotating shaft was designed. The head and tail of the outer sleeve are provided with screw holes with opposite threads. The pressure-rotating shaft drives the expansion spring to expand outward, increasing the contact area and friction with the femoral neck, thereby achieving fracture reduction.
It simplifies the operation process, improves the holding force in the cancellous bone of the femoral head, and can efficiently complete fracture reduction through rotation and pushing and pulling, reducing operation time and reduction difficulty.
Smart Images
Figure CN223914191U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an implant, specifically a repositionable anti-rotation implant for femoral neck and intertrochanteric fractures of the femur, belonging to the field of orthopedic implant manufacturing technology. Background Technology
[0002] In orthopedic clinical practice, femoral neck fractures and intertrochanteric fractures are relatively common conditions. Due to muscle traction after a fracture, the femoral neck may shift. If open reduction is performed during surgery, the wound will be too large, affecting blood supply and resulting in a longer recovery period for the patient.
[0003] Currently, minimally invasive methods are commonly used in clinical practice for fracture reduction. This involves using multiple bone pins for traction and rotation to achieve reduction. The specific steps are as follows: an incision is made in the skin, and multiple 3.2mm guide pins are inserted. Fluoroscopy confirms the correct position of the guide pins. Under C-arm fluoroscopy, fracture reduction is performed using the guide pins. After reduction, temporary fixation is achieved with bone pins. A bone drill is inserted along the central guide pin to enlarge the diameter of the screw channel. A suitable-length spiral blade or lag screw is then screwed into the cancellous bone of the femoral neck along the guide pin. Depending on the fracture type and stability, it is determined whether additional screws are needed to control fracture displacement and rotation. Finally, the wound is rinsed and sutured. Because the bone pins are typically 3.2mm diameter threaded pins, which are relatively thin, and the threads on the pins have limited holding force in the cancellous bone of the femoral head, the reduction time is longer and the effect is less pronounced. Summary of the Invention
[0004] The purpose of this invention is to provide a repositionable anti-rotation implant for femoral neck and intertrochanteric fractures that has high holding power in the cancellous bone of the femoral head and can be repositioned by rotation and pushing / pulling.
[0005] To achieve the above objectives, the technical solution of this utility model is: a repositionable anti-rotation implant for femoral neck and intertrochanteric fractures of the femur, the innovation of which lies in: including an outer sheath and a pressure-applying rotation shaft.
[0006] The outer sleeve has a front threaded hole and a rear threaded hole at its head and tail, respectively, with the threads of the front and rear threads facing opposite directions. The pressure-applying rotating shaft is inserted into the inner hole of the outer sleeve and is simultaneously threadedly connected to both the front and rear threaded holes of the outer sleeve.
[0007] The front end of the outer sleeve is provided with multiple axial elongated grooves along its circumference, and the multiple axial elongated grooves divide the front end of the outer sleeve into multiple expansion springs. When the pressure rotating shaft is rotated, the head and tail of the outer sleeve move horizontally in opposite directions at the same time, so that the multiple expansion springs on the outer sleeve expand outward at the same time, thereby increasing the holding force of the outer sleeve on the femoral neck.
[0008] In the above technical solution, each expansion piece has three elastic grooves on both sides and along its length to reduce the local structural strength and increase the elasticity. Two of the elastic grooves are located at both ends of the expansion piece and are arc-shaped grooves. The remaining elastic groove is located in the middle part of the expansion piece and is an elongated groove.
[0009] In the above technical solution, after the expansion spring expands outward, the middle part is bent and pushed outward, and at the same time, the expansion spring is deformed into two equilateral segment structures. The length of the elastic grooves at both ends of the expansion spring is 1mm to 5mm, and the length of the elastic groove in the middle part is 1mm to 6mm.
[0010] In the above technical solution, each expansion spring has several anti-slip grooves on its outer surface to increase the friction between it and the bone interface.
[0011] In the above technical solution, the anti-slip groove is a V-shaped groove, the included angle of the V-shaped groove is 40° to 90°, and the groove spacing is 0.5mm to 5mm.
[0012] In the above technical solution, the outer sleeve includes a connecting tube and an expansion tube that are connected as one piece and arranged coaxially. The tail of the connecting tube is provided with a rear threaded hole, and the head of the expansion tube is provided with a rotating shaft connector, which is provided with a front threaded hole.
[0013] In the above technical solution, one end of the expansion tube and the connection part with the connecting tube are provided with an annular groove, and the other end and the inner side of the rotating shaft connector are also provided with an annular groove. The direction of the notch of the annular groove is opposite to the direction of the notch of the elastic groove provided on the expansion spring.
[0014] In the above technical solution, the outer tube is provided with four arc-shaped expansion springs.
[0015] In the above technical solution, the expansion tube is provided with four arc-shaped expansion springs, and the outer diameter of the connecting tube is larger than the outer diameter of the expansion tube.
[0016] In the above technical solution, the pressure rotating shaft includes a shaft body. The head and tail of the shaft body have threaded sections that form threaded connections with the front threaded hole and the rear threaded hole, respectively. The outer diameter of the threaded section at the head of the shaft body is larger than the outer diameter of the threaded section at the tail. At the same time, the threaded section at the tail of the shaft body also has an internal hex hole for easy insertion of a screwdriver and driving its rotation.
[0017] The positive effects of this invention are: after using the repositionable anti-rotation implant for femoral neck and intertrochanteric fractures of this invention, because this invention includes an outer sleeve and a pressure-applying rotating shaft,
[0018] The outer sleeve has a front threaded hole and a rear threaded hole at its head and tail, respectively, with the threads of the front and rear threads facing opposite directions. The pressure-applying rotating shaft is inserted into the inner hole of the outer sleeve and is simultaneously threadedly connected to both the front and rear threaded holes of the outer sleeve.
[0019] The front end of the outer sleeve is provided with multiple axial elongated grooves along its circumference, which divide the front end of the outer sleeve into multiple expansion springs. When the pressure rotating shaft is rotated, the head and tail of the outer sleeve move horizontally in opposite directions simultaneously, causing the multiple expansion springs on the outer sleeve to expand outwards at the same time, thereby increasing the holding force of the outer sleeve on the femoral neck.
[0020] A 3.2 mm guide pin was pre-inserted in the center of the femoral neck, and its correct position was confirmed by fluoroscopy.
[0021] The bone drill bit enters along the guide needle to establish and expand the channel path of the implant of this utility model.
[0022] The outer sheath and pressure rotating shaft are advanced along the guide pin through the channel path and pushed into the femoral neck bone.
[0023] The rotating pressure shaft causes the head and tail of the outer sleeve to move horizontally in opposite directions simultaneously, i.e., the head and tail move relative to each other. This causes multiple expansion springs at the front end of the outer sleeve to expand outward, opening up the front end structure of the outer sleeve and increasing the contact area and friction between it and the bone interface. At this time, the fracture can be reduced under C-arm fluoroscopic imaging through rotation, traction and other actions, ensuring that the expansion springs of the outer sleeve have a high holding force on the bone interface. After the reduction is completed, the wound is rinsed and sutured.
[0024] Compared to existing technologies that use multiple 3.2 mm diameter threaded bone pins and require complex repositioning operations involving traction and rotation, this invention allows for individual repositioning, making the operation simpler and faster. Existing technologies involve inserting tension screws or spiral blades into the body, requiring screwing or tapping to implant the device. This invention, however, is directly inserted into the drilled hole, and the expansion of the product head achieves stable fixation of the implant, enabling rotation and traction repositioning operations. Therefore, this invention is not only convenient to operate but also provides high holding force within the cancellous bone of the femoral head, allowing for repositioning of fractured areas through rotation and push-pull methods. Attached Figure Description
[0025] Figure 1 This is a structural schematic diagram of one specific embodiment of the present invention;
[0026] Figure 2 This is a schematic diagram of the outer sleeve of this utility model;
[0027] Figure 3 yes Figure 2 A schematic diagram of the full cross-section structure;
[0028] Figure 4 This is a schematic diagram of the expanded state of this utility model;
[0029] Figure 5 This is a three-dimensional structural diagram of the present invention. Detailed Implementation
[0030] The present invention will be further described below with reference to the accompanying drawings and the given embodiments, but it is not limited thereto.
[0031] like Figure 1 , 2 As shown in Figures 3, 4, and 5, a repositionable anti-rotation implant for femoral neck and intertrochanteric fractures includes an outer sheath 1 and a pressure rotation shaft 2. The outer sheath 1 is a hollow cylindrical structure. Specifically...
[0032] The outer sleeve 1 has a front threaded hole 11 and a rear threaded hole 12 at its head and tail, respectively. The threads of the front threaded hole 11 and the rear threaded hole 12 are in opposite directions. The pressure-applying rotating shaft 2 is inserted into the inner hole of the outer sleeve 1, and the pressure-applying rotating shaft 2 is simultaneously threaded to both the front threaded hole 11 and the rear threaded hole 12 of the outer sleeve 1.
[0033] The front end of the outer sleeve 1 is provided with multiple axial elongated grooves along its circumference, and the multiple axial elongated grooves divide the front end of the outer sleeve 1 into multiple expansion springs 13. When the pressure rotating shaft 2 is rotated, the head and tail of the outer sleeve 1 move horizontally in opposite directions at the same time, so that the multiple expansion springs 13 on the outer sleeve 1 expand outward at the same time, thereby increasing the holding force of the outer sleeve 1 on the femoral neck.
[0034] Furthermore, such as Figure 2 As shown, in order to reduce the structural strength of the ends and middle part of the expansion spring and facilitate the expansion spring to open, each expansion spring 13 has three elastic grooves 14 on both sides and along its length to reduce the local structural strength and increase the elasticity. Two of the elastic grooves 14 are located at the ends of the expansion spring 13 and are arc-shaped grooves. The remaining elastic groove 14 is located in the middle part of the expansion spring 13 and is an elongated groove.
[0035] Furthermore, such as Figure 4As shown, in order to obtain a stable structure after the expansion spring expands, it can be made into a triangular shape (roof shape), and a triangle can obtain a relatively stable structure. After the expansion spring 13 expands outward, the middle part is bent and pushed outward, and at the same time, the expansion spring 13 is deformed into two equilateral segments. The length of the elastic grooves at both ends of the expansion spring 13 is 1mm to 5mm, and the length of the elastic groove in the middle part is 1mm to 6mm.
[0036] Furthermore, such as Figure 1 , 2 As shown in Figures 3, 4, and 5, in order to enhance the friction between the expansion spring and the bone interface, improve the holding force of the implant in the bone, and prevent the implant from slipping during operation steps such as rotation and lifting, each expansion spring 13 has several anti-slip grooves 15 on its outer surface to increase the friction between it and the bone interface.
[0037] Furthermore, in order to further improve the rationality of the structure, the anti-slip groove 15 of this utility model is a V-shaped groove, the included angle of the V-shaped groove is 40° to 90°, and the groove spacing is 0.5mm to 5mm.
[0038] Furthermore, such as Figure 3 As shown, in order to further improve the structural rationality and to enable the expansion spring of the expansion tube 17 to open up after driving the pressure rotating shaft, the outer sleeve 1 includes a connecting tube 16 and an expansion tube 17 that are connected as one piece and arranged coaxially. The tail of the connecting tube 16 is provided with a rear screw hole 12, and the head of the expansion tube 17 is provided with a rotating shaft connector 18, which has a front screw hole 11.
[0039] Furthermore, such as Figure 3 As shown, in order to further reduce the structural strength of both ends of the expansion tube and facilitate the opening and expansion of the front end structure, an annular groove is provided at one end of the expansion tube 17 and at the connection part with the connecting tube 16, and an annular groove is also provided at the other end and on the inner side of the rotating shaft connector 17. The direction of the notch of the annular groove is opposite to the direction of the notch of the elastic groove 14 provided on the expansion spring 13.
[0040] Furthermore, to make the structure more rational and to ensure good structural stability after expansion, the outer tube 1 is provided with four arc-shaped expansion tabs 13. When the total length of the outer tube 1 decreases by 2mm, the upward expansion height of the expansion tabs 13 increases by 10mm. The overall height of the expansion tube 17 after expansion is between 20mm and 30mm.
[0041] Furthermore, to enhance the overall strength of the outer sheath and achieve femoral neck fracture reduction, the outer diameter of the connecting tube 16 is larger than the outer diameter of the expansion tube 17. The expansion tube 17 of this invention is provided with four arc-shaped expansion springs 13, which ensures a more stable and reliable expansion structure after expansion, and provides higher holding force within the cancellous bone of the femoral head.
[0042] Furthermore, such as Figure 1 As shown, in order to drive the rotating pressure shaft, the rotating pressure shaft 2 includes a shaft body. The head and tail of the shaft body have threaded sections that form a threaded connection with the front threaded hole 11 and the rear threaded hole 12, respectively. The outer diameter of the threaded section at the head of the shaft body is larger than the outer diameter of the threaded section at the tail. At the same time, the threaded section at the tail of the shaft body also has an internal hex hole 21 for easy insertion of a screwdriver and driving its rotation.
[0043] The specific operating steps of this utility model are as follows:
[0044] A 3.2 mm guide pin was pre-inserted in the center of the femoral neck, and its correct position was confirmed by fluoroscopy.
[0045] The bone drill bit enters along the guide needle to establish and expand the channel path of the implant of this utility model.
[0046] The outer sleeve 1 and the pressure rotating shaft 2 are advanced along the guide pin in the channel path and pushed into the femoral neck bone (e.g. Figure 1 (as shown),
[0047] When a screwdriver is inserted into the inner six-hole 21 of the pressure-operated rotating shaft 2 and rotated, the head and tail of the outer sleeve 1 move horizontally in opposite directions simultaneously, i.e., the head and tail move relative to each other. This causes the multiple expansion tabs 13 on the expansion tube 17 at the front end of the outer sleeve 1 to expand outwards simultaneously, opening up the front end structure of the outer sleeve 1 (e.g., Figure 5 As shown in the figure, the contact area and friction between the outer sheath and the bone interface are increased. At this time, the fracture can be reduced under C-arm fluoroscopy by rotation, traction and other actions to ensure that the expansion fins of the outer sheath have a high holding force on the bone interface. After the reduction is completed, the wound is rinsed and sutured.
[0048] Compared to existing technologies that use multiple 3.2 mm diameter threaded bone pins and require complex repositioning operations involving traction and rotation, this invention allows for individual repositioning, making the operation simpler and faster. Existing technologies involve inserting tension screws or spiral blades into the body, requiring screwing or tapping to implant the device. This invention, however, is directly inserted into the drilled hole, and the expansion of the product head achieves stable fixation of the implant, enabling rotation and traction repositioning operations. Therefore, this invention is not only convenient to operate but also provides high holding force within the cancellous bone of the femoral head, allowing for repositioning of fractured areas through rotation and push-pull methods.
[0049] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A repositionable antirotation implant for femoral neck and intertrochanteric fractures, characterized in that: It includes an outer tube (1) and a pressure rotating shaft (2). The head and tail of the outer sleeve (1) are respectively provided with a front threaded hole (11) and a rear threaded hole (12). The threads of the front threaded hole (11) and the rear threaded hole (12) are opposite in direction. The pressure rotating shaft (2) is inserted into the inner hole of the outer sleeve (1), and the pressure rotating shaft (2) is simultaneously threaded to the front threaded hole (11) and the rear threaded hole (12) of the outer sleeve (1). The front end of the outer tube (1) is provided with multiple axial elongated grooves along its circumference, and the multiple axial elongated grooves divide the front end of the outer tube (1) into multiple expansion springs (13). When the pressure rotating shaft (2) is rotated, the head and tail of the outer tube (1) move horizontally in opposite directions at the same time, so that the multiple expansion springs (13) on the outer tube (1) expand outward at the same time, which is used to increase the holding force of the outer tube (1) on the femoral neck.
2. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 1, characterized in that: Each expansion piece (13) has three elastic grooves (14) on both sides and along its length to reduce local structural strength and increase elasticity. Two of the elastic grooves (14) are located at both ends of the expansion piece (13) and are arc-shaped grooves. The remaining elastic groove (14) is located in the middle part of the expansion piece (13) and is an elongated groove.
3. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 2, characterized in that: After the expansion piece (13) expands outward, the middle part bends and pushes outward, and at the same time, the expansion piece (13) is deformed into two equilateral segment structures. The length of the elastic groove at both ends of the expansion piece (13) is 1mm~5mm, and the length of the elastic groove in the middle part is 1mm~6mm.
4. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 1, characterized in that: Each expansion spring (13) has several anti-slip grooves (15) on its outer surface to increase the friction between it and the bone interface.
5. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 4, characterized in that: The anti-slip groove (15) is a V-shaped groove with an included angle of 40°~90° and a groove spacing of 0.5mm~5mm.
6. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 1, characterized in that: The outer sleeve (1) includes a connecting tube (16) and an expansion tube (17) that are connected as one piece and arranged coaxially. The tail of the connecting tube (16) is provided with a rear screw hole (12), and the head of the expansion tube (17) is provided with a rotating shaft connector (18). The rotating shaft connector (18) is provided with a front screw hole (11).
7. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 6, characterized in that: One end of the expansion tube (17) and the connection part with the connecting tube (16) are provided with an annular groove, and the other end of the expansion tube (17) and the inner side of the rotating shaft connector (18) are also provided with an annular groove. The direction of the notch of the annular groove is opposite to the direction of the notch of the elastic groove (14) provided on the expansion spring (13).
8. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 1, characterized in that: The outer tube (1) is provided with four arc-shaped expansion springs (13).
9. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 6, characterized in that: The expansion tube (17) is provided with four arc-shaped expansion springs (13), and the outer diameter of the connecting tube (16) is larger than the outer diameter of the expansion tube (17).
10. The repositionable antirotation implant for femoral neck and intertrochanteric fractures according to claim 1, characterized in that: The pressurized rotating shaft (2) includes a shaft body. The head and tail of the shaft body have threaded sections that form a threaded connection with the front threaded hole (11) and the rear threaded hole (12), respectively. The outer diameter of the threaded section at the head of the shaft body is larger than the outer diameter of the threaded section at the tail. At the same time, the threaded section at the tail of the shaft body also has an internal hex hole (21) that facilitates the insertion of a screwdriver and drives its rotation.