A locking nail-in-nail fixation structure
By designing a matching structure of a limiting cylinder and an abutment block in the locking pin, the problem of loosening between the locking pin and the bone plate is solved, achieving a more secure fixation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU GEMMED MEDICAL INSTR
- Filing Date
- 2026-03-09
- Publication Date
- 2026-05-29
AI Technical Summary
Existing locking pins lack further anti-loosening structures after locking with the bone plate, resulting in insufficient fixation.
A locking screw fixing structure was designed. By setting a limiting cylinder and an abutment block on the screw head, the tightening and loosening operation of the limiting cylinder pushes the abutment block to tightly abut against the inner wall of the bone plate. The anti-dislodgement protrusion and anti-dislodgement groove cooperate to prevent the abutment block from falling off, thereby enhancing the overall fixation between the locking screw and the bone plate.
It effectively reduces the possibility of the locking pins loosening unexpectedly, making the locking pins and bone plates form a more secure overall connection and ensuring the fixation effect.
Smart Images
Figure CN122096941A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of locking pin technology, and more specifically, to a locking pin fixing structure. Background Technology
[0002] Locking screws are commonly used components in orthopedic surgery, primarily in conjunction with bone plates. They are typically made of materials such as titanium alloys and stainless steel, possessing excellent tensile strength and toughness, making them suitable for repairing hard tissue defects, especially fractures of the limbs. During use, the threads on the screw head interlock with the reverse threads of the bone plate, eliminating the need for the plate to press against the bone surface during installation. This reduces pressure on the periosteum, protecting it and its blood supply.
[0003] However, some existing locking pins still have room for improvement. Although their heads and bone plates can lock together, they lack further structures to prevent loosening. Summary of the Invention
[0004] To address the aforementioned problems, this application provides a locking pin fixing structure.
[0005] The locking pin fixing structure provided in this application adopts the following technical solution:
[0006] A locking pin fixing structure includes a locking pin and a bone plate. The locking pin includes a pin head, a threaded portion, and a pin tail. The bone plate has a set of through pin grooves. The top of the pin head has a cylindrical groove and a hexagonal recess sequentially formed from the center outwards. A limiting cylinder is placed inside the cylindrical groove. A concave thread is formed inwards along the opening of the cylindrical groove. A cross groove is formed at the top of the limiting cylinder. A convex thread matching the concave thread is formed from top to bottom along the outer edge of the limiting cylinder. A set of receiving grooves is formed on the outer side of the lower end of the pin head. The receiving grooves are connected to the cylindrical grooves, and an abutment block is embedded inside the receiving grooves, extending into the interior of the cylindrical grooves.
[0007] Furthermore, the limiting cylinder is provided with a tapered part, a contracting part and an anti-detachment part in sequence from top to bottom at the position of the contact block, and an annular anti-detachment protrusion is provided along the upper outer edge of the anti-detachment part.
[0008] Furthermore, the side of the abutment block closest to the limiting cylinder is provided with an inclined surface, and the side of the abutment block away from the limiting cylinder is provided with an abutment surface, and the bottom of the abutment block is provided with an anti-detachment groove.
[0009] Furthermore, the anti-detachment groove spans between the cylindrical groove and the storage groove, and the depth of the anti-detachment groove is equal to the height of the anti-detachment protrusion.
[0010] Furthermore, several anti-slip stripes are evenly distributed along the annular inner wall of the nail groove, and the anti-slip stripes are parallel to the contact surface of the contact block.
[0011] Furthermore, the contact surface is an arc-shaped surface, and when the contact surface is reset, it coincides with the circumferential surface of the lower end of the nail head.
[0012] Furthermore, the concave thread extends to the receiving groove, and the length of the convex thread is less than the length of the concave thread.
[0013] Furthermore, the number of storage slots does not exceed three, and the spacing between two adjacent storage slots is equal.
[0014] Furthermore, the depth of the cylindrical groove is greater than the length of the limiting cylinder.
[0015] Furthermore, the inclination angle of the inclined surface is the same as the inclination angle of the conical surface of the conical part, and the inclination angle of the inclined surface is not less than forty-five degrees.
[0016] In summary, this application includes at least one of the following beneficial technical effects:
[0017] (1) This application applies pressure to all the contact blocks simultaneously by tightening the limiting cylinder, thereby pushing the contact blocks to move outward along the storage groove until the contact blocks are tightly against the inner wall of the nail groove, thereby further assisting in fixing the locking nail, reducing the possibility of the locking nail loosening accidentally, and making the locking nail and the bone plate form a more solid whole.
[0018] (2) This application moves the anti-detachment protrusion upward by loosening the limiting cylinder, so that the anti-detachment protrusion can be inserted into the anti-detachment groove, thereby locking the contact block to prevent the contact block from falling out of the storage groove. Attached Figure Description
[0019] Figure 1 A schematic diagram of a locking pin fixing structure;
[0020] Figure 2 for Figure 1 Enlarged view of region A in the middle;
[0021] Figure 3 This is a schematic diagram of the structure when the contact block abuts against the bone plate in this application;
[0022] Figure 4 This is a schematic diagram of the limiting cylinder in this application;
[0023] Figure 5 This is a schematic diagram of the structure of the contact block in this application;
[0024] Figure 6 This is a schematic diagram of the structure when the abutment block is reset in this application;
[0025] Figure 7 This is a schematic diagram of the structure in this application where the limiting cylinder locks the contact block;
[0026] Figure 8 for Figure 7 A magnified view of a portion of the image.
[0027] The following are the labeling instructions in the diagram: 1. Locking pin; 11. Pin head; 111. Hexagonal groove; 112. Cylindrical groove; 113. Retention groove; 114. Concave thread; 12. Threaded part; 13. Pin tail; 14. Limiting cylinder; 141. Cross groove; 142. Convex thread; 143. Conical part; 144. Contraction part; 145. Anti-dislodgement part; 146. Anti-dislodgement protrusion; 15. Abutment block; 151. Bevel; 152. Anti-dislodgement groove; 153. Abutment surface; 2. Bone plate; 3. Pin groove; 31. Anti-slip stripe. Detailed Implementation
[0028] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0029] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" 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 a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0031] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.
[0032] This application discloses a locking screw fixation structure, including a locking screw 1 and a bone plate 2. It is understood that the locking screw 1 and the bone plate 2 are made of titanium alloy or high-strength stainless steel. Please refer to [link to relevant documentation]. Figure 1 , Figure 2 and Figure 3 The locking pin 1 includes a pin head 11, a threaded portion 12, and a pin tail 13. The upper half of the pin head 11 is threaded. A set of through pin grooves 3 are formed on the bone plate 2. The upper half of the pin grooves 3 is provided with reverse threads corresponding to the position of the pin head 11, so that the pin head 11 and the bone plate 2 can lock each other. Since this is a common technical means, it will not be described in detail. The locking pin 1 passes through the corresponding pin groove 3. When the locking pin 1 is tightened, the pin head 11 of the locking pin 1 is embedded in the pin groove 3, and the top of the pin head 11... The part has a cylindrical groove 112 and a hexagonal groove 111 sequentially opened from the center outwards. Medical personnel can use a hand-held torque-limiting screwdriver to insert the hexagonal cone head into the hexagonal groove 111, thereby driving the locking nail 1 to rotate. For example, when the locking nail 1 is driven to rotate clockwise, the locking nail 1 is tightened, and when the locking nail 1 is driven to rotate counterclockwise, the locking nail 1 is loosened. It can be understood that the tightening and loosening mentioned in this application refer to the process of the threaded part 12 and the nail tail 13 of the locking nail 1 being screwed into and out of the patient's bone.
[0033] It should be noted that, in order to ensure the stability of the center of gravity of the locking pin 1, the central axes of the cylindrical groove 112 and the hexagonal groove 111 are aligned. Figure 2 , Figure 3 and Figure 4 As shown, a limiting cylinder 14 is placed inside the cylindrical groove 112. The depth of the cylindrical groove 112 is greater than the length of the limiting cylinder 14. The limiting cylinder 14 fits against the inner wall of the cylindrical groove 112. A concave thread 114 is formed inward along the groove opening of the cylindrical groove 112. Further, a cross-shaped groove 141 is formed at the top of the limiting cylinder 14. Medical personnel can insert the screwdriver bit into the cross-shaped groove 141 using a Phillips screwdriver (or a torque limiting screwdriver) to rotate the limiting cylinder 14. More specifically, a convex thread 142 matching the concave thread 114 is formed from top to bottom along the outer edge of the limiting cylinder 14. The convex thread 142 is integrally formed with the limiting cylinder 14, allowing the limiting cylinder 14 to be threadedly connected to the screw head 11. Please refer to [link to relevant documentation]. Figure 8 It is understandable that the length of the convex thread 142 is less than the length of the concave thread 114, and the concave thread 114 extends to the receiving groove 113. This arrangement allows the limiting cylinder 14 to have sufficient room to move.
[0034] Please see Figures 4 to 8A set of storage slots 113 are provided on the outer side of the lower end of the nail head 11. The storage slots 113 are connected to the cylindrical slots 112, and an abutment block 15 is embedded inside the storage slots 113. The abutment block 15 extends into the interior of the cylindrical slots 112. It can be understood that in order to ensure the firmness of the nail head 11 structure, the number of storage slots 113 is no more than three, and the spacing between two adjacent storage slots 113 is equal. In order to allow the abutment block 15 to be moved by the limiting cylinder 14, the limiting cylinder 14 is provided with a conical part 143, a contraction part 144, and an anti-detachment part 144 in sequence from top to bottom corresponding to the position of the abutment block 15. 45. The conical portion 143, the contraction portion 144, and the anti-detachment portion 145 form a receiving space to accommodate the portion of the contact block 15 extending into the cylindrical groove 112. It should be noted that an annular anti-detachment protrusion 146 is provided along the upper outer edge of the anti-detachment portion 145, and an inclined surface 151 is provided on the side of the contact block 15 near the limiting cylinder 14. The inclination angle of the inclined surface 151 is the same as the inclination angle of the conical surface of the conical portion 143. Thus, when the limiting cylinder 14 is pressed down, its conical portion 143 has sufficient contact area with the inclined surface 151 of the contact block 15, so as to push the contact block 15 along the receiving groove 112. 13 moves outward until the contact block 15 is tightly abutted against the bone plate 2, thereby strengthening the overall stability of the locking nail 1 and the bone plate 2. According to force analysis, when the inclination angle of the inclined plane 151 is not less than 45 degrees, it is easier for the limiting cylinder 14 to push the contact block 15 to move horizontally when it presses down. Of course, the inclination angle of the inclined plane 151 should be less than 90 degrees. Although a larger inclination angle of the inclined plane 151 makes it easier for the limiting cylinder 14 to push the contact block 15 to move horizontally, the downward movement of the limiting cylinder 14 should not be too large due to the limited depth of the cylindrical groove 112. For example, when the inclination angle of the inclined plane 151 is... When the angle is equal to 45 degrees, if the limiting cylinder 14 moves down one unit, the contact block 15 will also move one unit under pressure. When the inclination angle of the inclined plane 151 is greater than 45 degrees, if the limiting cylinder 14 moves down one unit, the contact block 15 will move less than one unit under pressure. Therefore, the inclination angle of the inclined plane 151 is most suitable when it is around 60 degrees. It should be further noted that the side of the contact block 15 away from the limiting cylinder 14 is provided with an abutment surface 153. To ensure the flatness of the circumferential surface of the nail head 11, the abutment surface 153 is an arc-shaped surface, and when the abutment surface 153 is reset, it coincides with the circumferential surface of the lower end of the nail head 11 (e.g., ...). Figure 8As shown), the contact block 15 is in its initial position at this time. To increase the friction between the contact block 15 and the bone plate 2, several anti-slip stripes 31 are evenly provided along the annular inner wall of the nail groove 3. The anti-slip stripes 31 are parallel to the contact surface 153 of the contact block 15, and the texture of the anti-slip stripes 31 is very shallow. More specifically, an anti-dislodgement groove 152 is provided at the bottom of the contact block 15. The anti-dislodgement groove 152 spans between the cylindrical groove 112 and the storage groove 113. This ensures that after the contact block 15 is installed, the anti-detachment groove 152 is always directly above the anti-detachment protrusion 146. It can be understood that the depth of the anti-detachment groove 152 is equal to the height of the anti-detachment protrusion 146. When the limiting cylinder 14 is loosened, the limiting cylinder 14 moves upward, causing the anti-detachment protrusion 146 to move upward as well. This allows the anti-detachment protrusion 146 to insert into the interior of the anti-detachment groove 152, thereby locking the contact block 15 in place and preventing the contact block 15 from falling out of the storage groove 113.
[0035] The implementation principle of a locking nail fixing structure in this application embodiment is as follows:
[0036] When the locking pin 1 is needed, hospital personnel first use a relevant tool (such as a torque limiting screwdriver) to pass the locking pin 1 through the pin groove 3 on the bone plate 2 and gradually screw it into the patient's bone until the pin head 11 of the locking pin 1 is embedded in the pin groove 3. At this time, the abutment block 15 is located inside the pin groove 3, and the locking pin 1, bone plate 2 and patient bone are in a relatively fixed state. Then, the limiting cylinder 14 can be tightened again by using a torque limiting screwdriver (or a Phillips screwdriver) to make the limiting cylinder 14 move downward. During this process, the tapered part 143 of the limiting cylinder 14 gradually presses down and simultaneously applies pressure to the inclined surface 151 of all the abutment blocks 15, thereby pushing all the abutment blocks 15 to move outward synchronously along the receiving groove 113 until the abutment block 15 is tightly abutted against the inner wall of the pin groove 3. This can further assist in fixing the locking pin 1, reduce the possibility of the locking pin 1 loosening accidentally, and make the locking pin 1 and bone plate 2 form a more solid whole.
[0037] When the patient recovers and the locking pin 1 needs to be removed, medical staff can first loosen the limiting cylinder 14 using a torque limiting screwdriver (or a Phillips screwdriver) to release the pressure on the contact block 15. At this time, the contact block 15 will disengage from the inner wall of the nail groove 3 under the reaction force of the inner wall of the nail groove 3, or it will only lightly contact the inner wall of the nail groove 3 and will not be in a tight state (i.e., a lateral loose state). Therefore, it will not hinder the subsequent loosening of the locking pin 1. It is understandable that as the limiting cylinder 14 is further loosened, the limiting cylinder 14 will drive the anti-disengagement groove 152 and the anti-disengagement protrusion 146 to move upward as a whole, so that the anti-disengagement protrusion 146 inserts into the contact block 15. The anti-dislodgement groove 152 is tightened until the anti-dislodgement protrusion 146 presses against the abutment block 15, thereby pressing the horizontally loose abutment block 15 vertically upward to reduce the frictional resistance that the abutment block 15 may form with the nail groove 3 when the locking nail 1 is loosened laterally. It should be noted that at this time, the limiting cylinder 14 is still located inside the cylindrical groove 112 and does not extend into the hexagonal groove 111. Loosening the limiting cylinder 14 is also a continuous process and will not waste time. Then, medical personnel can use the torque limiting screwdriver again to loosen the locking nail 1 until the locking nail 1 gradually detaches from the patient's bone and bone plate 2, thereby completing the nail removal process of the locking nail 1.
[0038] Additionally, it should be noted that during factory assembly of the locking pin 1 in a clean environment, the limiting cylinder 14 is first inserted into the cylindrical groove 112 and gradually tightened, causing the limiting cylinder 14 to move down along the cylindrical groove 112 to the desired position. Figure 6 When the position is shown, insert the abutment block 15 into the nail head 11 along the storage groove 113, and then loosen the limiting cylinder 14 to insert its anti-detachment protrusion 146 into the anti-detachment groove 152 of the abutment block 15 until the anti-detachment protrusion 146 presses the abutment block 15 firmly, thereby pressing and limiting the abutment block 15 to its initial position before use (e.g., Figure 8 As shown in the figure, the assembly of locking pin 1 is thus completed.
[0039] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A locking pin fixing structure, comprising a locking pin (1) and a bone plate (2), wherein the locking pin (1) comprises a pin head (11), a threaded portion (12) and a pin tail (13), and the bone plate (2) is provided with a set of through pin grooves (3), characterized in that: The top of the nail head (11) has a cylindrical groove (112) and a hexagonal groove (111) sequentially formed from the center outwards. A limiting cylinder (14) is placed inside the cylindrical groove (112). A concave thread (114) is formed inwards along the opening of the cylindrical groove (112). A cross groove (141) is formed on the top of the limiting cylinder (14). A convex thread (142) matching the concave thread (114) is formed from top to bottom along the outer edge of the limiting cylinder (14). A set of receiving grooves (113) is formed on the outer side of the lower end of the nail head (11). The receiving grooves (113) are connected to the cylindrical grooves (112), and an abutment block (15) is embedded inside the receiving grooves (113). The abutment block (15) extends into the interior of the cylindrical grooves (112).
2. The locking pin fixing structure according to claim 1, characterized in that: The limiting cylinder (14) is provided with a tapered part (143), a contraction part (144) and an anti-detachment part (145) in sequence from top to bottom at the position of the contact block (15), and an annular anti-detachment protrusion (146) is provided along the upper outer edge of the anti-detachment part (145).
3. The locking pin fixing structure according to claim 1, characterized in that: The abutment block (15) has an inclined surface (151) on the side close to the limiting cylinder (14), and an abutment surface (153) on the side away from the limiting cylinder (14). The bottom of the abutment block (15) has an anti-detachment groove (152).
4. The locking pin fixing structure according to claim 3, characterized in that: The anti-detachment groove (152) spans between the cylindrical groove (112) and the storage groove (113), and the depth of the anti-detachment groove (152) is equal to the height of the anti-detachment protrusion (146).
5. The locking pin fixing structure according to claim 1, characterized in that: A plurality of anti-slip stripes (31) are evenly provided along the annular inner wall of the nail groove (3), and the anti-slip stripes (31) are parallel to the contact surface (153) of the contact block (15).
6. The locking pin fixing structure according to claim 5, characterized in that: The contact surface (153) is an arc-shaped surface, and when the contact surface (153) is reset, it coincides with the circumferential surface of the lower end of the nail head (11).
7. The locking pin fixing structure according to claim 1, characterized in that: The concave thread (114) extends to the receiving groove (113), and the length of the convex thread (142) is less than the length of the concave thread (114).
8. The locking pin fixing structure according to claim 1, characterized in that: The number of the storage slots (113) shall not exceed three, and the spacing between two adjacent storage slots (113) shall be equal.
9. The locking pin fixing structure according to claim 1, characterized in that: The depth of the cylindrical groove (112) is greater than the length of the limiting cylinder (14).
10. The locking pin fixing structure according to claim 3, characterized in that: The inclination angle of the inclined surface (151) is the same as the inclination angle of the conical surface of the conical part (143), and the inclination angle of the inclined surface (151) is not less than forty-five degrees.