Anti-looseness skull fixing system and fixing method thereof

Abstract

The application discloses a slack-preventing skull fixing system and a fixing method thereof, and belongs to the technical field of medical devices. The system comprises a connecting sheet, a screw and a buckle cap assembly. The buckle cap assembly comprises a buckle cap body and an elastic element arranged in the buckle cap body. The connecting sheet is provided with a buckle position, and the buckle cap body can be buckled and fixed in the buckle position. After installation, the elastic element can apply a continuous axial force to the screw head to prevent the screw from loosening and retreating. The buckle cap body comprises an elastic buckle, an inner slide and an intermediate connecting rod. The elastic element is a spring, one end of which abuts against the inner top wall of the buckle cap body, and the other end of which abuts against the slide. One end of the intermediate connecting rod is connected with the slide, and the other end of the intermediate connecting rod extends out of the buckle cap body and abuts against the screw head. The system solves the technical problem that the traditional skull fixing device is prone to loosening, and improves the safety and stability of skull repair surgery.

Description

Technical Field

[0001] This application relates to an anti-loosening skull fixation system and its fixation method, belonging to the field of medical device technology. Background Technology

[0002] Cranioplasty is a common neurosurgical procedure, primarily used to repair skull defects caused by trauma, surgery, or disease. During cranioplasty, the repair graft must be reliably fixed to the skull margins to ensure both the repair's effectiveness and patient safety. Currently, commonly used cranioplasty fixation systems include screw fixation, titanium screw fixation, and titanium mesh fixation.

[0003] Traditional cranial fixation systems typically use screws to secure the connecting plate to the skull and repair patch for a stable connection. For example, CN222889003U discloses a cranial fixation connection structure and its fixing screw, including a connecting plate and screws for fixing the connecting plate to the repair patch and skull respectively. The screw includes a body and a cap adapted to the body. The top of the body has a connecting section with several symmetrically arranged inverted trapezoidal longitudinal axes, and an injection molding hole is provided in the middle of the connecting section. The cap is injection molded onto the top of the body. While this structure can fix the skull and repair patch, it fails to solve the problem of screw loosening over long-term use.

[0004] CN222516960U discloses a double-locking skull fixation system, including a connecting piece and a groove plug. The connecting piece includes a flat plate with fixing components at both ends. The longitudinal section of the fixing components is L-shaped. This system achieves double locking through the connecting piece and the groove plug, which improves the fixation stability to some extent, but still lacks an effective protection mechanism against screw loosening.

[0005] CN118021487B discloses a cranial repair connection assembly and its installation method, comprising a lower base and an upper cover. The upper cover includes a cover plate and a one-way bolt. Several inclined protrusions are provided on both sides of the one-way bolt, which cooperate with the grooves of the lower base to form a locking structure. While this solution simplifies the installation process, it does not specifically address the problem of loose screws.

[0006] CN222676534U discloses an anti-loosening skull locking groove, including a repair patch and a curved rod movably connected thereto. The lower part of the repair patch has an inwardly facing groove, the upper part of the curved rod has a locking part adapted to the groove, and the bottom end of the curved rod has an insertion part for insertion into the skull. This solution improves the fixation stability through the locking structure, but it still does not solve the problem of screw loosening in traditional screw fixation systems.

[0007] CN116421287B discloses a cranioplasty fixation system, including a drilled fixation component. The drilled fixation component includes a drilled expansion fixation part, which is an annular structure with an opening and a tapered screw hole at its center. A screw is screwed in to expand the expansion fixation part, causing it to lock into the drilled hole. While this solution avoids direct fixation with metal nails, there is still a risk of loosening after long-term use.

[0008] However, existing cranioplasty systems generally share a common problem: after cranioplasty, the screws are subjected to stress from head movements over a long period. This repeated stress can cause the connection between the screw and the skull to gradually loosen. The risk of screw loosening is particularly high in areas of frequent head movement, potentially leading to serious complications such as screw dislodgement or even infection. Current technologies lack an effective mechanism to apply continuous axial pressure to the screws to prevent loosening, which challenges the long-term stability of cranioplasty. Furthermore, once a screw loosens, a second surgery is usually required for adjustment or replacement, increasing patient suffering and medical burden, as well as the risk of infection and other complications.

[0009] Therefore, there is an urgent need for a cranioplasty system that can prevent screw loosening in order to improve the long-term stability of cranioplasty and the postoperative quality of life of patients. Summary of the Invention

[0010] The technical problem this invention aims to solve is that, in the prior art, after skull repair, the screws need to withstand the stress generated by head movements. Long-term repeated stress may cause the connection between the screws and the skull to gradually loosen, especially in areas with frequent movement, where there is a risk of screw loosening, falling off, and infection.

[0011] The technical solution adopted by this invention to solve its technical problem is: In a first aspect, the present invention provides an anti-loosening skull fixation system, comprising: Connecting piece, used to connect the skull to the repair piece; Screws are used to secure the connecting piece to the skull and / or the repair piece; A buckle assembly, comprising a buckle body and an elastic element disposed within the buckle body; The connecting piece is provided with a snap-fit ​​position, and the snap cap body can be snapped and fixed in the snap-fit ​​position; when the snap cap assembly is installed on the connecting piece, the elastic element can apply a continuous axial force to the head of the screw to prevent the screw from loosening and moving back.

[0012] In one embodiment of the present invention, the cap body includes: An elastic buckle is used to form a snap-fit ​​connection with the buckle position on the connecting piece; Furthermore, the elastic element is a spring, and the buckle body is provided with a slider and an intermediate connecting rod; One end of the spring abuts against the inner top wall of the buckle body, and the other end abuts against the slider; one end of the intermediate connecting rod is connected to the slider, and the other end extends out of the buckle body and is configured to abut against the screw head.

[0013] In one embodiment of the present invention, the lower end of the intermediate connecting rod is provided with a vertical groove, which slides in cooperation with a guide structure provided on the connecting piece or the buckle body to restrict the intermediate connecting rod to move only along its axial direction.

[0014] In one embodiment of the present invention, the slider is slidably engaged with the inner wall of the buckle body to ensure that the spring force can be effectively transmitted to the screw head through the slider and the intermediate connecting rod; Preferably, the cross-section of the slider is non-circular, and the buckle body is provided with a matching non-circular slide rail to prevent the slider and the intermediate connecting rod from rotating.

[0015] In one embodiment of the present invention, the spring is one of a helical spring, a disc spring, or an elastic rubber column.

[0016] In one embodiment of the present invention, the connecting piece, screw and buckle assembly are made of medical-grade metal material or medical-grade polymer material; Preferably, the medical-grade metal material is titanium or a titanium alloy, and the medical-grade polymer material is polyetheretherketone.

[0017] In one embodiment of the present invention, the connecting piece is an elongated strip structure, having at least one through hole for the screw to pass through and at least one fastener for mounting the cap assembly.

[0018] In one embodiment of the present invention, one of the buckle positions corresponds to one of the through holes, such that one of the buckle caps can apply an axial force to one of the screws.

[0019] In a second aspect, the present invention also provides a method for cranioplasty fixation, employing an anti-loosening cranioplasty fixation system as described in any one of the first aspects above, the method comprising the following steps: Step 1: Place the connecting piece between the skull and the repair piece, and use screws to pass through the connecting piece and initially tighten and fix it; Step 2: Press the buckle assembly into the buckle position on the connecting piece, so that the elastic element inside the buckle assembly continuously presses against the head of the screw through the transmission mechanism, thereby applying a continuous axial clamping force to the screw.

[0020] In one embodiment of the present invention, in step two, the lower end of the middle connecting rod of the buckle assembly slides along its vertical groove during installation and finally accurately abuts against the central recess or protrusion of the screw head.

[0021] The beneficial effects that this application can produce include: This invention introduces an elastic element into the cranial fixation system, enabling continuous axial pressure to be applied to the screw head, effectively preventing screw loosening and retraction. The continuous compressive force provided by the spring mechanism maintains fixation stability, ensuring good fixation even with slight bone absorption or movement. The cap design more effectively distributes stress, reducing the risk of the screw cutting into the bone, while the pressure provided by the spring offers a more uniform tension distribution, significantly reducing the risk of screw loosening, dislodgement, and infection. In cyclic loading tests, this system exhibits a significantly higher failure cycle count than traditional fixation systems, demonstrating its superior anti-loosening performance and long-term stability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the anti-loosening skull fixation system in one embodiment of this application; Figure 2 This is another structural schematic diagram of the anti-loosening skull fixation system in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of the anti-loosening skull fixation system with added caps in one embodiment of this application; Figure 4 Another structural schematic diagram of the anti-loosening skull fixation system with added buckles in one embodiment of this application; Figure 5 This application provides an embodiment of an anti-loosening skull fixation system. Figure 4 Enlarged structural diagram at point A; Figure 6 This is a schematic diagram of the structure of the cap body in an anti-loosening skull fixation system according to one embodiment of this application; Figure 7 This is a flowchart illustrating a cranial repair and fixation method according to one embodiment of this application; Attached image description: 1-Connecting piece; 11-Snap fastener; 12-Through hole; 2-Skull; 3-Repair piece; 4-Screw; 5-Snap cap body; 51-Elastic snap; 52-Slider; 53-Intermediate connecting rod; 54-Vertical groove; 6-Spring. Detailed Implementation

[0023] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0024] Example 1 In this embodiment, please refer to Figure 1-6 This embodiment provides an anti-loosening skull fixation system, which includes three main parts: a connecting piece 1, a screw 4, and a buckle assembly.

[0025] Connecting piece 1 is used to connect skull 2 ​​and repair piece 3. Connecting piece 1 is a long strip structure with through hole 12 and fastener 11. Through hole 12 allows screw 4 to pass through, used to fix connecting piece 1 to skull 2 ​​and repair piece 3. Fastener 11 is used to install fastener assembly. One fastener 11 corresponds to one through hole 12, so that one fastener assembly can apply axial force to one screw 4.

[0026] Screw 4 is used to fix the connecting piece 1 to the skull 2 ​​and the repair piece 3. Screw 4 has a head and a threaded portion. The threaded portion passes through the through hole 12 on the connecting piece 1 and is screwed into the skull 2 ​​or the repair piece 3, thereby achieving a fixed connection between the connecting piece 1 and the skull 2 ​​or the repair piece 3.

[0027] The buckle assembly includes a buckle body 5 and an elastic element disposed within the buckle body. The buckle body 5 includes an elastic buckle 51 for forming a snap-fit ​​connection with the buckle position 11 on the connecting piece 1. A slider 52 and an intermediate connecting rod 53 are also disposed within the buckle body 5. The elastic element is a spring 6, one end of which abuts against the inner top wall of the buckle body 5, and the other end abuts against the slider 52. One end of the intermediate connecting rod 53 is connected to the slider 52, and the other end extends out of the buckle body 5 and is configured to abut against the head of the screw 4.

[0028] The lower end of the intermediate connecting rod 53 is provided with a vertical groove 54, which slides in engagement with a guide structure provided on the connecting piece 1 or the buckle body 5 to restrict the intermediate connecting rod 53 to move only along its axial direction. This design ensures that the intermediate connecting rod 53 can only move in the vertical direction, preventing it from shifting laterally or rotating, thereby ensuring the effective transmission of elastic force and the stability of the direction of action.

[0029] The slider 52 slides against the inner wall of the cap body 5 to ensure that the spring force of the spring 6 can be effectively transmitted to the head of the screw 4 through the slider 52 and the intermediate connecting rod 53. The cross-section of the slider 52 is non-circular, and the cap body 5 has a matching non-circular slide rail to prevent the slider 52 and the intermediate connecting rod 53 from rotating. This design enhances the stability of the system and ensures the precise transmission of the spring force.

[0030] Spring 6 can be selected from one of the following: a coil spring, a disc spring, or an elastic rubber column. Different types of spring 6 can be selected according to specific clinical needs and mechanical requirements to provide the most suitable elastic support force.

[0031] After the cap assembly is installed on the connecting piece 1, the elastic element can apply a continuous axial force to the head of the screw 4 to prevent the screw 4 from loosening and retracting. This design solves the problem that the screw 4 may loosen due to vibration or other factors in traditional cranial fixation systems, improving the stability and safety of the fixation system.

[0032] The connecting piece 1, screw 4, and buckle assembly are made of medical-grade metal or medical-grade polymer materials. In a preferred embodiment, the medical-grade metal material is titanium or titanium alloy, and the medical-grade polymer material is polyetheretherketone (PEEK). These materials have good biocompatibility and mechanical properties, meeting the clinical requirements for skull fixation.

[0033] In use, first place the connecting piece 1 at the junction between the skull 2 ​​and the repair piece 3, then use the screw 4 to fix the connecting piece 1 to the skull 2 ​​and the repair piece 3 through the through hole 12 on the connecting piece 1. Next, snap the elastic buckle 51 of the buckle assembly into the corresponding buckle position 11 on the connecting piece 1, so that the buckle assembly is firmly installed on the connecting piece 1. After installation, the spring 6 inside the buckle assembly applies continuous axial pressure to the head of the screw 4 through the slider 52 and the intermediate connecting rod 53, preventing the screw 4 from loosening due to external force or long-term use.

[0034] This anti-loosening skull fixation system applies a continuous axial force to the screw 4 through an elastic element, effectively preventing the screw 4 from loosening and retraction, improving the reliability and safety of skull fixation, reducing the risk of postoperative complications, and having important clinical application value for skull repair and reconstruction surgery.

[0035] Example 2 In this embodiment, please refer to Figure 7 This embodiment provides a cranioplasty fixation method using an anti-loosening cranioplasty fixation system. The detailed structure of this system has been described in Embodiment 1, and it includes three main parts: a connecting piece 1, screws 4, and a buckle assembly. The method includes the following steps: Step 1: Place the connecting piece 1 between the skull 2 ​​and the repair piece 3, and use the screw 4 to pass through the connecting piece 1 and initially tighten and fix the connecting piece 1; In this step, the positional relationship between the defect area of ​​skull 2 ​​and repair piece 3 is first determined, and the elongated connecting piece 1 is placed at the overlap between the edges of skull 2 ​​and repair piece 3. Then, a screw 4 of appropriate length is selected, and the screw 4 is passed through the through hole 12 on the connecting piece 1 and screwed into skull 2 ​​and repair piece 3. At this point, the screw 4 only needs to be initially tightened to ensure that there is a certain fixing force between the connecting piece 1 and skull 2 ​​and repair piece 3, but it does not need to be fully tightened. This initial fixation ensures that the connecting piece 1 will not shift when the cap assembly is installed later, and also facilitates the adjustment of the position of the connecting piece 1.

[0036] Step 2: Press the cap assembly into the buckle 11 on the connecting piece 1, so that the elastic element inside the cap assembly continuously presses against the head of the screw 4 through the transmission mechanism, thereby applying a continuous axial clamping force to the screw 4.

[0037] In this step, align the snap cap assembly with the snap-on position 11 on the connecting piece 1, and gently press the snap cap body 5 so that its elastic snap 51 forms a snap-on connection with the snap-on position 11. During installation, the lower end of the intermediate connecting rod 53 slides along its vertical groove 54 and finally accurately abuts against the central recess or protrusion of the screw head 4. The precise positioning of the intermediate connecting rod 53 ensures that the elastic force can be transmitted along the axial direction of the screw 4, minimizing the risk of the screw 4 loosening. After the snap cap assembly is installed, the internal spring 6 applies continuous axial pressure to the head of the screw 4 through the slider 52 and the intermediate connecting rod 53. This continuous pressure effectively prevents the screw 4 from loosening or retracting due to vibration or other external forces.

[0038] In a preferred embodiment, the lower end of the intermediate connecting rod 53 slides along its vertical groove 54 during installation and ultimately abuts precisely against the central recess or protrusion of the screw head 4. This precise positioning design ensures the stability and effectiveness of elastic force transmission, further enhancing the anti-loosening effect.

[0039] This cranioplasty fixation method applies continuous axial pressure to screw 4 through a cap assembly, effectively solving the problem of screw 4 easily loosening in traditional cranioplasty fixation systems, thus improving the success rate of cranioplasty and patient safety. This method is simple to operate, requires no special tools, is suitable for various cranioplasty surgeries, and has broad clinical application value.

[0040] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A cranial fixation system for preventing skull relaxation, characterized in that, include: Connecting piece (1), used to connect skull (2) and repair piece (3); Screws (4) are used to fix the connecting piece (1) to the skull (2) and / or the repair piece (3); A buckle assembly, comprising a buckle body (5) and an elastic element disposed within the buckle body (5); The connecting piece (1) is provided with a buckle (11), and the buckle body (5) can be snapped and fixed in the buckle (11); when the buckle assembly is installed on the connecting piece (1), the elastic element can apply a continuous axial force to the head of the screw (4) to prevent the screw (4) from loosening and retracting. The cap body (5) includes: An elastic buckle (51) is used to form a snap-fit ​​connection with the buckle (11) on the connecting piece (1); In addition, the elastic element is a spring (6), and the buckle body (5) is provided with a slider (52) and an intermediate connecting rod (53). One end of the spring (6) abuts against the inner top wall of the buckle body (5), and the other end abuts against the slider (52); a part of the intermediate connecting rod (53) is connected to the slider (52), and the other part extends out of the buckle body (5); the lower end of the intermediate connecting rod (53) is provided with a vertical groove (54); during installation, the lower end of the intermediate connecting rod (53) slides along the vertical groove (54) and abuts against the central recess or protrusion of the screw (4) head; The slider (52) slides against the inner wall of the buckle body (5) to ensure that the elastic force of the spring (6) can be effectively transmitted to the head of the screw (4) through the slider (52) and the intermediate connecting rod (53); The cross-section of the slider (52) is non-circular, and the cap body (5) is provided with a matching non-circular slide to prevent the slider (52) and the intermediate connecting rod (53) from rotating.

2. The anti-loosening skull fixation system according to claim 1, characterized in that, The spring (6) is one of a helical spring, a disc spring, or an elastic rubber column.

3. The anti-loosening skull fixation system according to claim 1, characterized in that, The connecting piece (1), screw (4) and buckle assembly are made of medical-grade metal or medical-grade polymer materials; The medical-grade metal material is titanium or titanium alloy, and the medical-grade polymer material is polyetheretherketone.

4. The anti-loosening skull fixation system according to claim 1, characterized in that, The connecting piece (1) is a long strip structure, with at least one through hole (12) for the screw (4) to pass through and at least one fastener (11) for installing the buckle assembly.

5. The anti-loosening skull fixation system according to claim 4, characterized in that, One of the buckle positions (11) is provided corresponding to one of the through holes (12), such that one of the buckle cap assemblies can apply an axial force to one of the screws (4).

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