Sacroiliac screw device

Abstract

This invention provides a sacroiliac screw device comprising: a threaded hole provided within a fixing sleeve; a screw body inserted into the threaded hole, with the front end of the screw body extending out of the fixing sleeve; a support structure movably disposed on the side wall of the fixing sleeve along the radial direction, having a supporting position and a retracted position; a deformable member disposed between the support structure and the fixing sleeve, the deformable member driving the support structure to switch from the retracted position to the supporting position; and a biodegradable limiting sleeve having an initial state and a degraded state. In the initial state, the biodegradable limiting sleeve is fitted around the outer periphery of the fixing sleeve, with the support structure and the deformable member both located between the biodegradable limiting sleeve and the fixing sleeve, and the support structure in the retracted position. When the biodegradable limiting sleeve is in the degraded state, the deformable member drives the support structure to switch from the retracted position to the supporting position. The technical solution of this application effectively solves the problem of easy loosening of sacroiliac screws after implantation in related technologies.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a sacroiliac screw device. Background Technology

[0002] Currently, in sacroiliac joint implantation surgery, screws are often used to fix the sacroiliac joint to enhance joint stability. This technique is applied in clinical scenarios such as traumatic sacroiliac joint dislocation, chronic sacroiliac joint pain, sacral fracture, joint destruction secondary to ankylosing spondylitis, and correction of spinal-pelvic imbalance.

[0003] In related technologies, sacroiliac screws are mostly made of a single titanium alloy, whose elastic modulus is much higher than that of bone tissue, which can easily lead to stress shielding effect, thereby increasing the risk of screw loosening and failure. Summary of the Invention

[0004] The main objective of this invention is to provide a sacroiliac screw device to solve the problem of easy loosening of sacroiliac screws after implantation in related technologies.

[0005] To achieve the above objectives, according to one aspect of the present invention, a sacroiliac screw device is provided, comprising: a fixing sleeve having a threaded hole therein; a screw body inserted into the threaded hole, the front end of the screw body extending out of the fixing sleeve; a support structure movably disposed on the side wall of the fixing sleeve along the radial direction of the fixing sleeve, and having a supporting position and a retracted position; a deformable member disposed between the support structure and the fixing sleeve, the deformable member driving the support structure to switch the support structure from the retracted position to the supporting position; and a biodegradable limiting sleeve having an initial state and a degraded state, wherein when the biodegradable limiting sleeve is in the initial state, the biodegradable limiting sleeve is fitted around the outer periphery of the fixing sleeve, the support structure and the deformable member are both located between the biodegradable limiting sleeve and the fixing sleeve, and the support structure is in the retracted position; when the biodegradable limiting sleeve is in the degraded state, the deformable member drives the support structure to switch from the retracted position to the supporting position.

[0006] Furthermore, the biodegradable limiting sleeve is made of magnesium alloy or zinc alloy, while the fixing sleeve, screw body, support structure, and deformable parts are all made of titanium alloy.

[0007] Furthermore, the sacroiliac screw device also includes a positioning structure disposed between the fixing sleeve and the support structure.

[0008] Furthermore, the deformable part is an elastic part, and the positioning structure includes a positioning post and a positioning hole. The positioning post and the positioning hole can be inserted and fitted together. One of the positioning post and the positioning hole is set on the fixed sleeve, and the other of the positioning post and the positioning hole is set on the support structure. The elastic part is sleeved on the positioning post.

[0009] Furthermore, a receiving recess is provided on the side wall of the fixing sleeve, and the supporting structure is located in the receiving recess when the supporting structure is in the retracted position.

[0010] Furthermore, the outer wall of the fixed sleeve is provided with a first threaded segment and a second threaded segment, which are spaced apart along the axial direction of the fixed sleeve, and the support structure is located between the first threaded segment and the second threaded segment.

[0011] Furthermore, the outer wall of the biodegradable limiting sleeve is provided with a third threaded section and multiple grooves, each groove being intersected with the third threaded section, and the multiple grooves being spaced apart along the circumference of the biodegradable limiting sleeve on the third threaded section.

[0012] Furthermore, the support structure includes multiple support plates, which are spaced apart circumferentially along the fixed sleeve, and the support plates are provided with a porous structure.

[0013] Furthermore, a receiving groove is provided at the front end of the screw body, the receiving groove extends along the axial direction of the screw body, and in the radial direction of the screw body, the maximum size of the receiving groove is greater than the opening size of the receiving groove.

[0014] Furthermore, the rear end of the screw body is provided with a screw head structure. The sacroiliac screw device also includes a connecting rod, a screw seat, and a screw plug. The screw seat is sleeved on the screw body, the screw head structure is located inside the screw seat and is limited and matched with the screw seat, the connecting rod is inserted into the screw seat, and the connecting rod is clamped between the screw plug and the screw seat.

[0015] Furthermore, the sacroiliac screw device also includes a support base with a clearance hole, a first positioning recess at the top of the support base, and a second positioning recess at the bottom of the support base. The clearance hole connects with the first and second positioning recesses. A positioning part is provided on the connecting rod. The connecting rod is inserted into the first positioning recess, and the screw head structure is inserted into the second positioning recess. The positioning part abuts against the screw head structure through the clearance hole.

[0016] According to the technical solution of this invention, a threaded hole is provided inside the fixing sleeve, and the screw body is inserted into the threaded hole, with the front end of the screw body extending out of the fixing sleeve. A support structure is movably disposed on the side of the fixing sleeve along the radial direction, and the support structure has a supporting position and a retracted position. A deformable element is disposed between the support structure and the fixing sleeve. The deformable element can drive the support structure to switch from the retracted position to the supporting position. The biodegradable limiting sleeve has an initial state and a degraded state. When the biodegradable limiting sleeve is in the initial state, it is fitted around the outer periphery of the fixing sleeve, and both the support structure and the deformable element are located between the biodegradable limiting sleeve and the fixing sleeve, with the support structure in the retracted position. When the biodegradable limiting sleeve is in the degraded state, the deformable element drives the support structure to switch from the retracted position to the supporting position. Through the above configuration, after the sacroiliac screw device is implanted, the biodegradable limiting sleeve can be degraded in the human body. After the biodegradable limiting sleeve degrades, the deformable element is no longer constrained, thus allowing the deformable element to drive the support structure to switch from the retracted position to the supporting position. This allows the support structure to abut against the bone structure, further improving the positional stability of the sacroiliac screw. Therefore, the technical solution of this application effectively solves the problem of easy loosening of sacroiliac screws after implantation in related technologies. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A three-dimensional structural schematic diagram of an embodiment of the sacroiliac screw device according to the present invention is shown;

[0019] Figure 2 It shows Figure 1 A schematic diagram of the exploded structure of the sacroiliac screw device;

[0020] Figure 3 It shows Figure 1 A cross-sectional schematic diagram of the sacroiliac screw device in the first direction;

[0021] Figure 4 It shows Figure 1 A cross-sectional view of the sacroiliac screw device in the second direction;

[0022] Figure 5 It shows Figure 1 A three-dimensional structural diagram of the fixation sleeve of the sacroiliac screw device;

[0023] Figure 6 It shows Figure 1 A three-dimensional structural diagram of the fixing sleeve and deformable parts of the sacroiliac screw device;

[0024] Figure 7It shows Figure 1 A three-dimensional structural diagram of the screw body of the sacroiliac screw device;

[0025] Figure 8 It shows Figure 7 A partial enlarged view of the screw body;

[0026] Figure 9 It shows Figure 7 A cross-sectional view of the screw body;

[0027] Figure 10 It shows Figure 1 A three-dimensional structural diagram of the support structure of the sacroiliac screw device;

[0028] Figure 11 It shows Figure 1 A three-dimensional structural diagram of the biodegradable limiting sleeve of the sacroiliac screw device;

[0029] Figure 12 It shows Figure 1 A cross-sectional schematic diagram of the support base of the sacroiliac screw device.

[0030] The above figures include the following reference numerals:

[0031] 10. Fixing sleeve; 11. Threaded hole; 12. Receiving recess; 13. First threaded section; 14. Second threaded section; 20. Screw body; 21. Receiving groove; 22. Screw head structure; 30. Support structure; 31. Support plate; 40. Deformable part; 50. Biodegradable limiting sleeve; 51. Third threaded section; 52. Groove; 60. Positioning structure; 61. Positioning post; 62. Positioning hole; 71. Connecting rod; 711. Positioning part; 72. Screw seat; 73. Screw plug; 74. Support seat; 741. Clearance hole; 742. First positioning recess; 743. Second positioning recess. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] like Figures 1 to 4 As shown, in some embodiments, the sacroiliac screw device includes: a fixing sleeve 10, a screw body 20, a support structure 30, a deformable element 40, and a biodegradable limiting sleeve 50. The fixing sleeve 10 has a threaded hole 11. The screw body 20 passes through the threaded hole 11, with its front end extending out of the fixing sleeve 10. The support structure 30 is movably disposed on the side wall of the fixing sleeve 10 along its radial direction and has a supporting position and a retracted position. The deformable element 40 is disposed between the support structure 30 and the fixing sleeve 10, and drives the support structure 30 to switch the support structure 30 from the retracted position to the supporting position. The biodegradable limiting sleeve 50 has an initial state and a degradation state. When the biodegradable limiting sleeve 50 is in the initial state, it is fitted around the outer periphery of the fixed sleeve 10. The support structure 30 and the deformable member 40 are both located between the biodegradable limiting sleeve 50 and the fixed sleeve 10. The support structure 30 is in the retracted position. When the biodegradable limiting sleeve 50 is in the degradation state, the deformable member 40 drives the support structure 30 to switch from the retracted position to the support position.

[0036] Using the above technical solution, a threaded hole 11 is provided inside the fixing sleeve 10, and the screw body 20 is inserted into the threaded hole 11, with the front end of the screw body 20 extending out of the fixing sleeve 10. A support structure 30 is movably disposed on the side of the fixing sleeve 10 along the radial direction, and the support structure 30 has a supporting position and a retracted position. A deformable member 40 is disposed between the support structure 30 and the fixing sleeve 10. The deformable member 40 can drive the support structure 30 to switch from the retracted position to the supporting position. The biodegradable limiting sleeve 50 has an initial state and a degraded state. When the biodegradable limiting sleeve 50 is in the initial state, it is fitted around the outer periphery of the fixing sleeve 10, and both the support structure 30 and the deformable member 40 are located between the biodegradable limiting sleeve 50 and the fixing sleeve 10, with the support structure 30 in the retracted position. When the biodegradable limiting sleeve 50 is in the degraded state, the deformable member 40 drives the support structure 30 to switch from the retracted position to the supporting position. With the above-described configuration, after the sacroiliac screw device is implanted, the biodegradable limiting sleeve 50 can degrade within the body. Once degraded, the deformable component 40 is no longer constrained, allowing it to drive the support structure 30 from its retracted position to its supporting position. This enables the support structure 30 to contact the bone structure, further improving the positional stability of the sacroiliac screw. Therefore, the above technical solution effectively solves the problem of easy loosening of sacroiliac screws after implantation in related technologies.

[0037] It should be noted that by setting the biodegradable limiting sleeve 50 and the deformable part 40 together, the time-delayed active expansion of the support structure 30 is achieved.

[0038] In the early stages of surgical implantation, the support structure 30 is in the retracted position, reducing implantation resistance and improving operational convenience. After the biodegradable limiting sleeve 50 gradually degrades in the body, the deformable part 40 releases the pre-tightening force, driving the support structure 30 to expand outward to the support position, filling the gaps caused by degradation, achieving synchronous enhancement of dynamic mechanical support and osseointegration, effectively solving the loosening problem of traditional rigid screws after bone absorption, and significantly improving long-term stability.

[0039] like Figures 1 to 4 as well as Figure 11 As shown, in some embodiments, the biodegradable limiting sleeve 50 is made of magnesium alloy or zinc alloy, while the fixing sleeve 10, screw body 20, support structure 30, and deformable component 40 are all made of titanium alloy. The aforementioned magnesium and zinc alloys are biodegradable in vivo, while titanium alloys offer better structural strength and improved implantation stability.

[0040] Furthermore, magnesium alloy or zinc alloy is used as the material for the biodegradable limiting sleeve 50, and its degradation rate matches the bone healing cycle, thus promoting bone regeneration while avoiding premature or late failure.

[0041] Titanium alloy components possess excellent biocompatibility and mechanical strength, and their electrochemical potential matches that of biodegradable metals. Combined with anodizing treatment, they can effectively inhibit galvanic corrosion, avoid local inflammation or material failure caused by contact with dissimilar metals, and thus improve the safety and long-term biostability of the sacroiliac screw device.

[0042] Specifically, magnesium alloys include Mg–Ca alloy systems, Mg–Zn alloy systems, Mg–Mn–Zn alloy systems, Mg–Si alloy systems, Mg–Ag alloy systems, or Mg–Li alloy systems. Zinc alloys include Zn–Mg alloy systems, Zn–Cu alloy systems, Zn–Ag alloy systems, Zn–Ca alloy systems, or Zn–Sr alloy systems.

[0043] like Figures 1 to 6 as well as Figure 10 As shown, in some embodiments, the sacroiliac screw device further includes a positioning structure 60, which is disposed between the fixing sleeve 10 and the support structure 30. The positioning structure 60 provides good stability for movement between the support structure 30 and the fixing sleeve 10, and ensures the support position of the support structure 30.

[0044] like Figures 2 to 6 As shown, in some embodiments, the deformable member 40 is an elastic member, and the positioning structure 60 includes a positioning post 61 and a positioning hole 62. The positioning post 61 and the positioning hole 62 can be inserted into each other. One of the positioning post 61 and the positioning hole 62 is disposed on the fixed sleeve 10, and the other of the positioning post 61 and the positioning hole 62 is disposed on the support structure 30. The elastic member is sleeved on the positioning post 61. The aforementioned positioning post 61 and the positioning hole 62 can be inserted into each other, thus achieving a guiding fit. Furthermore, the elastic member being sleeved on the positioning post 61 can position the elastic member, thereby making the position of the elastic member more stable.

[0045] It should be noted that when the support structure 30 is in the support position, part of the positioning post 61 is located inside the positioning hole 62. This ensures the positional stability of the support structure 30 and prevents the support structure 30 from easily separating from the fixing sleeve.

[0046] like Figure 5 and Figure 6 As shown, in some embodiments, a receiving recess 12 is provided on the side wall of the fixing sleeve 10. When the support structure 30 is in the retracted position, the support structure 30 is located within the receiving recess 12. The receiving recess 12 can accommodate the support structure 30, so that the position of the support structure 30 is more stable when it is in the retracted position. Furthermore, the biodegradable limiting sleeve 50 can reduce the space occupied and the amount of material used.

[0047] It should be noted that by providing a receiving recess 12 on the side wall of the fixing sleeve 10, the support structure 30 is completely hidden inside the structure in the retracted state, which greatly reduces the cross-sectional profile during implantation, reduces traction and damage to the surrounding soft tissue, and improves the patency of the surgical approach.

[0048] At the same time, it avoids the support structure 30 from accidentally snagging on tissues during the operation, thereby improving the safety of implantation and the smoothness of operation.

[0049] like Figure 5 and Figure 6 As shown, in some embodiments, the outer wall of the fixing sleeve 10 is provided with a first threaded segment 13 and a second threaded segment 14, which are spaced apart along the axial direction of the fixing sleeve 10, and the support structure 30 is located between the first threaded segment 13 and the second threaded segment 14. The aforementioned arrangement of the first threaded segment 13 and the second threaded segment 14 makes the implantation of the sacroiliac screw device easier.

[0050] The double-threaded segment structure design of the first threaded segment 13 and the second threaded segment 14 enables the fixing sleeve 10 to achieve axial segmental anchoring in the bone tissue, enhancing the overall pull-out resistance.

[0051] The support structure 30 is located between the first threaded section 13 and the second threaded section 14, so that it can act directly on the middle section of the bone after being spread open, avoiding the proximal and distal ends with lower bone density, and more effectively transferring mechanical loads to the high-density bone area, thereby improving mechanical stability; at the same time, it avoids the support structure 30 interfering with the osseointegration of the threads.

[0052] like Figures 1 to 4 as well as Figure 11 As shown, in some embodiments, the outer wall of the biodegradable limiting sleeve 50 is provided with a third threaded segment 51 and a plurality of grooves 52, each groove 52 being intersected with the third threaded segment 51, and the plurality of grooves 52 being spaced apart along the circumference of the biodegradable limiting sleeve 50 on the third threaded segment 51. This configuration enables the biodegradable limiting sleeve 50 to be implanted and to stably connect and engage with the bone structure when the biodegradable limiting sleeve 50 is in its initial state.

[0053] The outer wall of the biodegradable limiting sleeve 50 is provided with a cross-distributed third thread segment 51 and multiple grooves 52, which enhances its initial anchoring ability in bone tissue and prevents rotation or displacement during surgery.

[0054] On the other hand, the groove 52, as a degradation guiding channel, can accelerate the penetration of body fluids and the diffusion of corrosion products, achieving a controllable, homogeneous, and predictable degradation rate, avoiding sudden structural failure caused by excessively rapid local degradation, and ensuring that the timing of expansion is synchronized with the bone healing process.

[0055] Specifically, the ratio between the thickness of the biodegradable retaining sleeve 50 and its maximum inner diameter is between 0.05 and 0.15. This ensures a secure fixation effect.

[0056] like Figures 1 to 6 as well as Figure 10 As shown, in some embodiments, the support structure 30 includes a plurality of support plates 31, which are spaced apart circumferentially along the fixing sleeve 10. Each support plate 31 has a porous structure. The simple structure of the support plate 31 results in good support stability. Furthermore, the porous structure allows bone structures to ingrow into it, thus achieving biological fixation.

[0057] Specifically, the support plate 31 is arc-shaped, and the arc-shaped support plate 31 can fit against the side wall of the fixing sleeve 10, which can ensure the positional stability of the support plate 31.

[0058] like Figures 1 to 4 as well as Figures 7 to 9 As shown, in some embodiments, the front end of the screw body 20 is provided with a receiving groove 21, which extends along the axial direction of the screw body 20. In the radial direction of the screw body 20, the maximum size of the receiving groove 21 is larger than the opening size of the receiving groove 21. When the screw body 20 is implanted, the receiving groove 21 can accommodate bone structures. That is, when the screw body 20 is screwed in, fragments of the patient's own bone structure can enter into the receiving groove 21, which can better achieve biological fixation, that is, the bone structure can grow into the receiving groove 21.

[0059] Furthermore, the aforementioned receiving groove 21 is designed to collect bone fragments generated during drilling, preventing bone fragments from clogging the threads or causing implantation resistance.

[0060] Meanwhile, bone fragments are retained in the receiving groove 21, providing a natural osteogenic microenvironment for subsequent bone tissue growth, promoting in-situ bone regeneration, improving bone integration efficiency, and reducing the risk of secondary surgery.

[0061] Specifically, the receiving groove 21 includes a first groove and a second groove. The front end of the screw body 20 includes a tip and a column. The first groove is disposed on the tip, and the second groove is disposed on the column. A baffle is disposed between the tip and the column, that is, the baffle divides the receiving groove into the first groove and the second groove. This arrangement can separate bone structure fragments, that is, achieve biological fixation separately, thus improving the fixation effect.

[0062] The baffle is provided with multiple through holes at intervals. The through holes allow the bone structures in the first and second grooves to grow into each other, which can further improve the fixation effect.

[0063] like Figures 1 to 4 as well as Figures 7 to 9As shown, in some embodiments, the rear end of the screw body 20 is provided with a screw head structure 22. The sacroiliac screw device also includes a connecting rod 71, a screw seat 72, and a screw plug 73. The screw seat 72 is sleeved on the screw body 20. The screw head structure 22 is located inside the screw seat 72 and is limited to cooperate with the screw seat 72. The connecting rod 71 is inserted into the screw seat 72 and is clamped between the screw plug 73 and the screw seat 72. The nail seat 72 and the nail head structure 22 are nested together. The nail seat 72 has a connecting through hole and an inner protrusion at the bottom of the connecting through hole. The front end of the screw body 20 passes through the nail seat 72 through the connecting through hole. The nail head structure 22 abuts against the inner protrusion and is located inside the connecting through hole. The side wall of the nail seat 72 has a clearance notch that communicates with the connecting through hole. The connecting rod 71 is located inside the clearance notch and can cooperate with the nail head structure 22. The screw plug 73 is connected to the connecting through hole and abuts against the connecting rod 71, which makes the position of the connecting rod 71 more stable.

[0064] Specifically, the screw head structure 22 and the screw seat 72 limit each other, enabling multi-angle connection between the screw body 20 and the connecting rod 71, allowing for flexible adjustment of the angle of the connecting rod 71 during the operation and improving the intraoperative adaptability; the screw plug 73 can provide a high pre-tightening force and a fixation method that prevents loosening.

[0065] like Figures 1 to 4 as well as Figures 7 to 12 As shown, in some embodiments, the sacroiliac screw device further includes a support base 74, which has a clearance hole 741. A first positioning recess 742 is provided at the top of the support base 74, and a second positioning recess 743 is provided at the bottom of the support base 74. The clearance hole 741 connects to the first positioning recess 742 and the second positioning recess 743. A positioning part 711 is provided on the connecting rod 71. The connecting rod 71 is inserted into the first positioning recess 742, and the screw head structure 22 is inserted into the second positioning recess 743. The positioning part 711 abuts against the screw head structure 22 through the clearance hole 741. The positioning part 711 is a positioning ball head, which is inserted into the clearance hole. This arrangement further improves the positional stability of the connecting rod.

[0066] Specifically, the nail holder 72 has a first hole on its side wall, and the support base 74 has a second hole on its side wall. The first and second holes are connected by a rod, which enables the positioning of the nail holder 72 and the support base 74. The rod can be deformably set. The nail holder 72 also has a third hole on its side wall, and the size of the third hole is larger than the size of the first hole.

[0067] The usage process of the sacroiliac screw device in this embodiment is as follows: During implantation, the screw body 20 and the screw seat 72 are first assembled. During implantation, the thread diameter of the screw body 20 is smaller than that of the fixing sleeve 10, which facilitates bone occlusion and implantation. At the same time, the receiving groove 21 at the front end of the screw body 20 can collect bone fragments generated during occlusion, which is beneficial for promoting bone ingrowth later. Finally, the remaining components are installed according to the assembly method.

[0068] After the sacroiliac screw device is implanted, the biodegradable limiting sleeve 50 degrades over time, simultaneously promoting bone tissue growth. Subsequently, the deformable element 40 in the fixation sleeve 10 and support structure 30 expands the support structure 30, filling the gap left by the degradation of the biodegradable limiting sleeve 50 and increasing stability. The support structure 30 is a trabecular bone structure, which facilitates bone tissue growth into it, further increasing stability.

[0069] During daily activities, the mechanical load generated by the patient is transmitted through the connecting rod 71. The mechanical load is then transmitted sequentially to the screw body 20, the fixing sleeve 10, and the support structure 30 through the positioning part 711. Since there is a deformable part 40 between the fixing sleeve 10 and the support structure 30, the mechanical load is further transmitted to the support structure 30 through the deformable part 40, causing the support structure 30 to move slightly under mechanical stimulation, thereby further promoting bone growth.

[0070] In the description of this invention, it should be understood that "a plurality of" means two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, perpendicular, horizontal," and "top, bottom" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms 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 limiting the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0071] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0072] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. In particular, unless there is a clear contradiction or logical conflict in the context, any technical feature in any embodiment disclosed in this specification can be arbitrarily combined with other technical features in any one or more other embodiments to form a new technical solution. All possible variations formed by combining different features, which can be conceived by those skilled in the art based on the technical teachings provided by the present invention, should be considered as fully disclosed in this specification, and these combinations also fall within the scope of protection claimed by the present invention.

Claims

1. A sacroiliac screw device, characterized in that, include: A fixing sleeve (10) is provided with a threaded hole (11) inside the fixing sleeve (10); The screw body (20) is inserted into the threaded hole (11), and the front end of the screw body (20) extends out of the fixing sleeve (10). The support structure (30) is movably disposed on the side wall of the fixed sleeve (10) in the radial direction of the fixed sleeve (10), and has a supporting position and a retractable position; A deformable element (40) is disposed between the support structure (30) and the fixed sleeve (10), the deformable element (40) driving the support structure (30) to switch the support structure (30) from the retracted position to the supported position; A biodegradable limiting sleeve (50) has an initial state and a degradation state. When the biodegradable limiting sleeve (50) is in the initial state, the biodegradable limiting sleeve (50) is sleeved on the outer periphery of the fixed sleeve (10). The support structure (30) and the deformable member (40) are both located between the biodegradable limiting sleeve (50) and the fixed sleeve (10). The support structure (30) is in the recycling position. When the biodegradable limiting sleeve (50) is in the degradation state, the deformable member (40) drives the support structure (30) to switch from the recycling position to the support position. The sacroiliac screw device further includes a positioning structure (60), which is disposed between the fixing sleeve (10) and the support structure (30); The deformable part (40) is an elastic part. The positioning structure (60) includes a positioning post (61) and a positioning hole (62). The positioning post (61) and the positioning hole (62) can be inserted and fitted together. One of the positioning post (61) and the positioning hole (62) is disposed on the fixed sleeve (10). The other of the positioning post (61) and the positioning hole (62) is disposed on the support structure (30). The elastic part is sleeved on the positioning post (61).

2. The sacroiliac screw device according to claim 1, characterized in that, The biodegradable limiting sleeve (50) is made of magnesium alloy or zinc alloy, and the fixing sleeve (10), the screw body (20), the support structure (30) and the deformable part (40) are all made of titanium alloy.

3. The sacroiliac screw device according to claim 1, characterized in that, The side wall of the fixed sleeve (10) is provided with a receiving recess (12). When the support structure (30) is in the retracted position, the support structure (30) is located in the receiving recess (12).

4. The sacroiliac screw device according to claim 1, characterized in that, The outer wall of the fixed sleeve (10) is provided with a first threaded section (13) and a second threaded section (14). The first threaded section (13) and the second threaded section (14) are spaced apart along the axial direction of the fixed sleeve (10). The support structure (30) is located between the first threaded section (13) and the second threaded section (14).

5. The sacroiliac screw device according to claim 1, characterized in that, The outer wall of the biodegradable limiting sleeve (50) is provided with a third threaded section (51) and a plurality of grooves (52), each groove (52) is intersecting the third threaded section (51), and the plurality of grooves (52) are provided on the third threaded section (51) at intervals along the circumference of the biodegradable limiting sleeve (50).

6. The sacroiliac screw device according to claim 1, characterized in that, The support structure (30) includes a plurality of support plates (31), which are spaced apart circumferentially along the fixed sleeve (10), and the support plates (31) are provided with a porous structure.

7. The sacroiliac screw device according to claim 1, characterized in that, The front end of the screw body (20) is provided with a receiving groove (21), which extends along the axial direction of the screw body (20). In the radial direction of the screw body (20), the maximum size of the receiving groove (21) is greater than the slot size of the receiving groove (21).

8. The sacroiliac screw device according to claim 1, characterized in that, The screw body (20) has a screw head structure (22) at its rear end. The sacroiliac screw device also includes a connecting rod (71), a screw seat (72), and a screw plug (73). The screw seat (72) is sleeved on the screw body (20). The screw head structure (22) is located inside the screw seat (72) and is limited to the screw seat (72). The connecting rod (71) is inserted into the screw seat (72). The connecting rod (71) is clamped between the screw plug (73) and the screw seat (72).

9. The sacroiliac screw device according to claim 8, characterized in that, The sacroiliac screw device also includes a support base (74), on which a clearance hole (741) is provided. A first positioning recess (742) is provided at the top of the support base (74), and a second positioning recess (743) is provided at the bottom of the support base (74). The clearance hole (741) is connected to the first positioning recess (742) and the second positioning recess (743). A positioning part (711) is provided on the connecting rod (71). The connecting rod (71) is inserted into the first positioning recess (742), and the screw head structure (22) is inserted into the second positioning recess (743). The positioning part (711) abuts against the screw head structure (22) through the clearance hole (741).

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