Bone screw implant for sacroiliac joint fusion and use method

Abstract

The invention discloses a bone screw implant for sacroiliac joint fusion and a using method, the bone screw implant comprises a fusion nail, the fusion nail is provided with a cutting edge, a coarse-pitch self-tapping thread and a fine-pitch self-tapping screw, and the coarse-pitch self-tapping thread and the fine-pitch self-tapping screw act on the sacrum and the ilium respectively; the bone grafts are arranged to be autogenous bones and / or allogeneic bones, and the bone grafts are combined with the human skeleton after the fusion nail is screwed into the human skeleton; the anti-rotation fixing cap comprises an outer ring seat, a middle seat and two anti-rotation connecting ribs; an inner hole of the fixing and locking nut is composed of a lower inner threaded hole and an upper inner hexagonal groove, the upper inner hexagonal groove is used for being matched with a hexagon wrench to conduct thread pressurization operation, and the fixing and locking nut is in downward pressure contact with the anti-rotation fixing cap to press the anti-rotation fixing cap into the ilium. By the adoption of the scheme, the gap between the sacrum and the ilium can be reduced or eliminated, meanwhile, the screw is prevented from retreating, and better fusion of the sacrum and the ilium is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of orthopedics, in particular to a bone screw implant for sacroiliac joint fusion. BACKGROUND

[0002] According to data statistics, the lifetime incidence of lower back pain worldwide is as high as 84%, of which sacroiliac joint disorder accounts for as high as 38%. Minimally invasive sacroiliac joint fusion is the gold standard for the treatment of sacroiliac joint disorder. At present, this operation is mainly carried out in Europe and the United States, and there are few related cases and operation cases reported in China and even in Asia. In addition to the lack of understanding and diagnosis of the disease, there is also a lack of implants and use methods required for related operations in China. In the process of sacroiliac joint fusion, a special bone screw implant is needed. There are many structure schemes for such implants, which are illustrated here. A Chinese patent is disclosed in the prior art, with the patent authorization publication number CN220046044U. The patent discloses a screw for sacroiliac joint fusion fixation, and the innovation point is that the hollow screw includes a nail rod and a driving nail tail connected as one body, the nail rod has an axial bone graft channel, the driving nail tail has a driving hole, the bone graft channel and the driving hole have the same axis and are mutually penetrated, the outer diameter of the driving nail tail is greater than the outer diameter of the nail rod, the outer peripheral wall of the nail rod is provided with threads, and the pitch of the threads at the head of the nail rod gradually decreases to the pitch of the threads at the tail.

[0003] From the above-mentioned prior art scheme, how to further reduce or eliminate the gap between the sacrum and the ilium and prevent the screw from retreating is helpful to the stability of the sacroiliac joint after operation to achieve better fusion. However, the sacroiliac joint fusion device disclosed in the prior art does not have the design of pressurization, anti-retreat, hollow with bone graft fusion window, and bone debris collection hole at the same time. Therefore, it is an important technical improvement direction. SUMMARY

[0004] The purpose of the present application is to provide a bone screw implant for sacroiliac joint fusion and a use method, which can reduce or eliminate the joint gap between the sacrum and the ilium, and is helpful to the better fusion of the sacroiliac joint.

[0005] The purpose of the present application is achieved as follows: a bone screw implant for sacroiliac joint fusion, comprising:

[0006] a fusion nail, the fusion nail is provided as a hollow screw and its hollow cavity penetrates along its axial direction, the fusion nail is provided with cutting edges, large-pitch self-tapping threads and small-pitch self-tapping threads which are distributed along the axial direction in sequence, the cutting edges are at the tip of the fusion nail, the pitch of the large-pitch self-tapping threads is greater than the pitch of the small-pitch self-tapping threads, and the large-pitch self-tapping threads and the small-pitch self-tapping threads act on the sacrum and the ilium respectively;

[0007] A plurality of bone grafts, which are autogenous bone and / or allogenic bone, are provided with a cylindrical section between the large pitch self-tapping screw and the small pitch self-tapping screw, and a plurality of bone grooves are provided around the central axis of the fusion nail in a circumferential direction, each bone graft filling a corresponding bone groove and combining with the human bone after the fusion nail is screwed into the human bone.

[0008] Further, the fusion nail is provided with at least two bone debris channels, which extend axially from the cutting edge and pass through the large pitch self-tapping screw and the small pitch self-tapping screw.

[0009] Further, the bone debris channels of the large pitch self-tapping screw and the small pitch self-tapping screw are provided with bone debris storage grooves.

[0010] Further, a rotation-preventing fixing cap is further included, which comprises a circular ring-shaped outer ring seat, a cylindrical middle seat, and two rotation-preventing connecting ribs, the rotation-preventing connecting ribs being between the outer ring seat and the middle seat and fixedly connected with the outer ring seat and the middle seat, the fusion nail being provided with two guide grooves extending downward from the head of the fusion nail, the outer ring seat being slidably sleeved with the fusion nail, the two rotation-preventing connecting ribs being respectively inserted into the two guide grooves, and the middle seat being inserted into the hollow cavity of the fusion nail.

[0011] Further, a fixing locking nut is further included, which has an upper and lower through inner hole, the inner hole of the fixing locking nut being composed of a lower internal thread hole and an upper internal hexagonal groove, the upper internal hexagonal groove being used for cooperating with a hexagonal wrench to perform a threaded pressing operation, the upper internal hexagonal groove and the lower internal thread hole being sequentially distributed from top to bottom, the head of the fusion nail being provided with a butt joint external thread, the lower internal thread hole of the fixing locking nut being sleeved with the butt joint external thread of the fusion nail, and the fixing locking nut being pressed to contact the rotation-preventing fixing cap downward to press the rotation-preventing fixing cap into the ilium.

[0012] Further, the outer ring seat of the rotation-preventing fixing cap is provided with a tapered surface at the lower end for guiding.

[0013] Further, the outer peripheral wall of the outer ring seat is circumferentially provided with a plurality of convex portions, the convex portions of the outer peripheral wall of the outer ring seat being pressed into the ilium during use.

[0014] Further, the convex portions of the outer peripheral wall of the outer ring seat are provided as sharp corner wings, and the cross-sectional structure of the sharp corner wings is triangular.

[0015] Further, the slot of each guide groove is provided as a V-shaped guide tapered surface.

[0016] Further, the middle seat is provided with an internal hexagonal hole.

[0017] As another aspect of the present application, a method for using the implant is provided, comprising the following steps:

[0018] S1. The bone graft is installed in the bone slot of the fusion nail, and the bone graft is set as autologous bone and / or allograft bone;

[0019] S2. The fusion nail is screwed into the sacral bone, and the large-pitch self-tapping thread and the small-pitch self-tapping screw are screwed into the sacral bone and the iliac bone, respectively;

[0020] S3. The anti-rotation fixing cap is sleeved on the upper end of the fusion nail, the outer ring seat is sleeved on the fusion nail, the two anti-rotation connecting ribs are inserted into the two guide grooves, respectively, and the middle seat is inserted into the hollow cavity of the fusion nail;

[0021] S4. The fixed locking nut is screwed into the upper end of the fusion nail, the lower internal thread hole of the fixed locking nut is threadedly connected with the butt joint external thread of the fusion nail, the anti-rotation fixing cap is pressed into the iliac bone through thread pressing, and the sharp corner wing piece is pressed into the iliac bone.

[0022] The beneficial effects of the present application are:

[0023] 1. The fusion nail has self-tapping threads with different pitches, the large-pitch self-tapping thread acts on the sacral bone, and the small-pitch self-tapping thread acts on the iliac bone. Because the pitches of the large-pitch self-tapping thread and the small-pitch self-tapping thread are different, the iliac bone is subjected to certain pressure during the screwing process, so that the iliac bone is forced to move towards the sacral bone, thereby reducing or eliminating the gap between the sacral bone and the iliac bone, and helping the sacral bone and the iliac bone to better fuse;

[0024] 2. The fixed locking nut and the fusion nail can be threadedly connected, the anti-rotation fixing cap is pressed into the iliac bone by the fixed locking nut, and the operation is convenient;

[0025] 3. The anti-rotation fixing cap is provided with a plurality of sharp corner wing pieces, the distal end of which is provided with a tapered surface, which is more easily pressed into the iliac bone, and effectively prevents the anti-rotation fixing cap from rotating and the nail from being removed, and the position is more stable;

[0026] 4. The upper end of the fusion nail is provided with a V-shaped guide tapered surface and a guide groove, and the slot opening of each guide groove is provided with a V-shaped guide tapered surface. The V-shaped guide tapered surface is provided to facilitate the anti-rotation connecting rib to enter the guide groove, and the internal hexagonal hole is provided to facilitate the adjustment of the anti-rotation fixing cap, so that the anti-rotation connecting rib enters the V-shaped guide tapered surface. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the general diagram of the present application.

[0028] Figure 2 is the structure diagram of the fixed locking nut.

[0029] Figure 3 is the first perspective view of the anti-rotation fixing cap.

[0030] Figure 4 is the second perspective view of the anti-rotation fixing cap.

[0031] Figure 5 is a schematic diagram of the stereoscopic structure of the fusion nail.

[0032] Explanation of reference numerals: 1 - fixed locking nut, 1a - upper internal hexagonal groove, 1b - lower internal threaded hole, 2 - anti-rotation fixing cap, 2a - outer ring seat, 2b - sharp corner wing, 2c - taper surface, 2d - middle seat, 2e - internal hexagonal hole, 2f - anti-rotation connecting rib, 3 - fusion nail, 301 - butting external thread, 302 - small-pitch self-tapping thread, 303 - large-pitch self-tapping thread, 304 - cutting edge, 305 - V-shaped guide taper surface, 306 - guide groove, 307 - bone chip storage groove, 308 - bone chip channel, 309 - bone groove, 4 - bone graft. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. Figures 1-5 The embodiments described are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] As shown in the accompanying drawings, Figures 1-5 a bone screw implant for sacroiliac joint fusion is proposed, comprising:

[0035] The fusion nail 3, as shown in the accompanying drawings, Figure 5 is a hollow screw and its hollow cavity penetrates through along its axial direction. The fusion nail 3 is provided with a cutting edge 304, a large-pitch self-tapping thread 303 and a small-pitch self-tapping thread 302 distributed along the axial direction in sequence. The cutting edge 304 is located at the tip of the fusion nail 3. The pitch of the large-pitch self-tapping thread 303 is greater than that of the small-pitch self-tapping thread 302. The large-pitch self-tapping thread 303 and the small-pitch self-tapping thread 302 act on the sacrum and the ilium respectively, i.e., connect the sacrum and the ilium respectively.

[0036] A plurality of bone grafts 4, which are autologous bone and / or allogeneic bone, are not excluded from other material options. A cylindrical section is left between the large-pitch self-tapping thread 303 and the small-pitch self-tapping thread 302, and a plurality of bone grooves 309 are arranged around the central axis of the fusion nail 3 in the cylindrical section. Each bone graft 4 fills a corresponding bone groove 309 and combines with the human bone after the fusion nail 3 is screwed into the human bone.

[0037] The anti-rotation fixing cap 2, as shown in the accompanying drawings, Figures 3-4As shown, the anti-rotation fixing cap 2 includes a circular ring-shaped outer ring seat 2a, a cylindrical middle seat 2d, and two anti-rotation connecting ribs 2f between the outer ring seat 2a and the middle seat 2d and fixedly connected with the outer ring seat 2a and the middle seat 2d, the fusion nail 3 is provided with two guide grooves 306 extending downward from the head of the fusion nail 3, the guide grooves 306 are communicated with the hollow cavity of the fusion nail 3, the outer ring seat 2a is sleeved with the fusion nail 3 in a sliding manner, the two anti-rotation connecting ribs 2f are respectively inserted into the two guide grooves 306, and the middle seat 2d is inserted into the hollow cavity of the fusion nail 3.

[0038] The fixed locking nut 1 has an upper and lower through hole, as shown in the figure Figure 2 As shown, the inner hole of the fixed locking nut 1 is composed of a lower internal thread hole 1b and an upper internal hexagonal groove 1a, the upper internal hexagonal groove 1a is used to cooperate with a hexagonal wrench to perform a threaded pressing operation, and the upper internal hexagonal groove 1a and the lower internal thread hole 1b are sequentially distributed from top to bottom, the head of the fusion nail 3 is provided with a butt joint external thread 301, the lower internal thread hole 1b of the fixed locking nut 1 is sleeved with the butt joint external thread 301 of the fusion nail 3, and the fixed locking nut 1 is pressed downward to contact the anti-rotation fixing cap 2 to press the anti-rotation fixing cap 2 into the ilium.

[0039] As shown in the figure Figure 1 , 5 As shown, the fusion nail 3 is provided with two bone debris passages 308, the bone debris passages 308 extend along the axial direction of the fusion nail 3 from the cutting edge 304 and penetrate through the large pitch self-tapping thread 303 and the small pitch self-tapping screw 302, and the positions of the bone debris passages 308 of the large pitch self-tapping thread 303 and the small pitch self-tapping screw 302 are provided with bone debris storage grooves 307.

[0040] As shown in the figure Figure 3 The outer peripheral wall of the outer ring seat 2a is uniformly distributed with a plurality of convex portions in the circumferential direction, the convex portions of the outer peripheral wall of the outer ring seat 2a are pressed into the ilium during use; the convex portions of the outer peripheral wall of the outer ring seat 2a are provided as sharp angle wings 2b, and the cross-sectional structure of the sharp angle wings 2b is triangular.

[0041] The lower end of the outer ring seat 2a of the anti-rotation fixing cap 2 is provided as a tapered surface 2c for guiding.

[0042] The above-mentioned implant follows the following use process:

[0043] 1. Under fluoroscopy, a 3.0mm guide needle is placed; a reamer is placed through the guide needle to expand the hole, and autologous bone debris on the reamer is collected. The collected autologous bone and allogeneic bone can be mixed and installed in the bone groove 309 of the fusion nail 3 (the type of bone graft 4 is not limited to the listed embodiments);

[0044] 2. The fusion nail 3 is screwed into the sacroiliac joint through the guide needle, and the large pitch self-tapping thread 303 and the small pitch self-tapping screw 302 are screwed into the sacrum and ilium, respectively;

[0045] 3. The anti-rotation fixing cap 2 is sleeved on the upper end of the fusion nail 3, the outer ring seat 2a is sleeved on the fusion nail 3, the two anti-rotation connecting ribs 2f are respectively inserted into the two guide grooves 306, and the middle seat 2d is inserted into the hollow cavity of the fusion nail 3;

[0046] 4. The fixed locking cap 1 is screwed into the upper end of the fusion nail 3, the lower internal thread hole 1b of the fixed locking cap 1 is threadedly matched with the butt joint external thread 301 of the fusion nail 3, the anti-rotation fixing cap 2 is pressed into the ilium by thread pressing, and the sharp corner wing 2b is pressed into the ilium.

[0047] It needs to be further explained that:

[0048] The fusion nail 3 has self-tapping threads with different pitches, the large-pitch self-tapping thread 303 acts (screws into) the sacrum, and the small-pitch self-tapping thread 302 acts (screws into) the ilium, because the pitches of the large-pitch self-tapping thread 303 and the small-pitch self-tapping thread 302 are different, the ilium is pressed in the direction of the sacrum during the screwing process, so as to narrow or eliminate the gap between the sacrum and the ilium, and help the sacroiliac joint to better fuse.

[0049] The upper end of the fusion nail 3 has the butt joint external thread 301, the fixed locking cap 1 has the lower internal thread hole 1b and the upper internal hexagonal groove 1a, the anti-rotation fixing cap 2 can be pressed into the ilium by the thread matching relationship between the fixed locking cap 1 and the fusion nail 3 and the downward pressing of the fixed locking cap 1, and the operation is convenient.

[0050] The anti-rotation fixing cap 2 is provided with a plurality of sharp corner wings 2b, the distal end of which is provided with a tapered surface 2c, which is more easily pressed into the ilium and effectively prevents the anti-rotation fixing cap 2 from rotating by itself, and the position is more stable.

[0051] The upper end of the fusion nail 3 is provided with a V-shaped guide tapered surface 305 and a guide groove 306, the slot of each guide groove 306 is provided with a V-shaped guide tapered surface 305; the middle seat 2d of the anti-rotation fixing cap 2 is provided with an internal hexagonal hole 2e, and the anti-rotation fixing cap 2 is also provided with an anti-rotation connecting rib 2f. The V-shaped guide tapered surface 305 is provided to facilitate the anti-rotation connecting rib 2f to enter the guide groove 306, and the internal hexagonal hole 2e is provided to facilitate the adjustment of the anti-rotation fixing cap 2 so that the anti-rotation connecting rib 2f enters the V-shaped guide tapered surface 305.

[0052] After the fixed locking cap 1 presses the anti-rotation fixing cap 2 into the ilium, the fixed locking cap 1, the anti-rotation fixing cap 2 and the fusion nail 3 become an integral whole, which cannot rotate along the shaft nor move axially, thereby effectively connecting the sacroiliac bone.

[0053] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "front", "back", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application; in the present application, it should be noted that the terms "mounting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally formed, or it can be mechanically connected, or it can be indirectly connected through an intermediate connecting part, and the specific meaning of the terms in the present application can be understood according to the specific circumstances.

[0054] It will be obvious to a person skilled in the art that, in view of the present application, the present application is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims, not the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be considered as limiting the claims involved.

[0055] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A bone screw implant for sacroiliac joint fusion, characterized in that, It comprises: a fusion nail (3) provided as a hollow screw and having a hollow cavity extending through along its axial direction, the fusion nail (3) being provided with a cutting edge (304), a large-pitch self-tapping thread (303) and a small-pitch self-tapping thread (302) arranged in sequence along the axial direction, the cutting edge (304) being located at the tip of the fusion nail (3), the pitch of the large-pitch self-tapping thread (303) being larger than that of the small-pitch self-tapping thread (302), the large-pitch self-tapping thread (303) and the small-pitch self-tapping thread (302) acting on the sacrum and the ilium, respectively; a plurality of bone grafts (4) provided as autologous bone and / or allogeneic bone, a cylindrical section being left between the large-pitch self-tapping thread (303) and the small-pitch self-tapping thread (302), and a plurality of bone grooves (309) being arranged in the cylindrical section and being circumferentially and uniformly distributed around the central axis of the fusion nail (3), each bone graft (4) filling a corresponding bone groove (309) and being combined with the human bone after the fusion nail (3) is screwed into the human bone.

2. A bone screw implant for sacroiliac joint fusion according to claim 1, wherein, The fusion nail (3) is provided with at least two bone debris channels (308) extending along the axial direction of the fusion nail (3) from the cutting edge (304) and penetrating through the large-pitch self-tapping thread (303) and the small-pitch self-tapping thread (302).

3. A bone screw implant for sacroiliac joint fusion according to claim 2, wherein, The positions of the bone debris channels (308) of the large-pitch self-tapping thread (303) and the small-pitch self-tapping thread (302) are provided with bone debris storage grooves (307).

4. A bone screw implant for sacroiliac joint fusion according to claim 1, wherein, It further comprises an anti-rotation fixing cap (2) comprising a circular ring-shaped outer ring seat (2a), a cylindrical middle seat (2d) and two anti-rotation connecting ribs (2f), the anti-rotation connecting ribs (2f) being located between and fixedly connected with the outer ring seat (2a) and the middle seat (2d), the fusion nail (3) being provided with two guide grooves (306) extending downward from the head thereof, the outer ring seat (2a) being slidably sleeved with the fusion nail (3), the two anti-rotation connecting ribs (2f) being respectively inserted into the two guide grooves (306), and the middle seat (2d) being inserted into the hollow cavity of the fusion nail (3).

5. A bone screw implant for sacroiliac joint fusion according to claim 4, wherein, It further comprises a fixed locking nut (1) having an inner hole extending through from top to bottom, the inner hole of the fixed locking nut (1) being composed of a lower internal thread hole (1b) and an upper internal hexagonal groove (1a), the upper internal hexagonal groove (1a) being used for cooperating with a hexagonal wrench to perform a threaded pressing operation, the upper internal hexagonal groove (1a) and the lower internal thread hole (1b) being arranged in sequence from top to bottom, the head of the fusion nail (3) being provided with a mating external thread (301), the lower internal thread hole (1b) of the fixed locking nut (1) being sleeved with the mating external thread (301) of the fusion nail (3), and the fixed locking nut (1) being pressed downward to contact the anti-rotation fixing cap (2) to press the anti-rotation fixing cap (2) into the ilium.

6. A bone screw implant for sacroiliac joint fusion according to claim 5, wherein, The lower end of the outer ring seat (2a) of the anti-rotation fixing cap (2) is provided as a tapered surface (2c) for guiding.

7. A bone screw implant for sacroiliac joint fusion according to claim 6, wherein, The outer circumferential wall of the outer ring seat (2a) is circumferentially distributed with several protruding sharp corner flaps (2b), and the sharp corner flaps (2b) of the outer circumferential wall of the outer ring seat (2a) are pressed into the ilium during use.

8. A bone screw implant for sacroiliac joint fusion according to claim 4, wherein, The slot of each guide slot (306) is provided with a V-shaped guide cone surface (305).

9. A bone screw implant for sacroiliac joint fusion according to claim 4, wherein, The intermediate seat (2d) is provided with an internal hexagonal hole (2e).

10. A method of using the bone screw implant for sacroiliac joint fusion of claim 7, wherein, The method comprises the following steps: S1. Installing the bone graft (4) into the bone groove (309) of the fusion nail (3); S2. Rotating the fusion nail (3) into the sacroiliac bone, and screwing the large-pitch self-tapping thread (303) and the small-pitch self-tapping screw (302) into the sacrum and the ilium, respectively; S3. Suits the anti-rotation fixing cap (2) on the upper end of the fusion nail (3), and suits the outer ring seat (2a) with the fusion nail (3), inserts the two anti-rotation connecting ribs (2f) into the two guide slots (306), and inserts the intermediate seat (2d) into the hollow cavity of the fusion nail (3); S4. Rotating the fixing lock nut (1) into the upper end of the fusion nail (3), and screwing the lower internal thread hole (1b) of the fixing lock nut (1) with the butt joint external thread (301) of the fusion nail (3), and pressing the anti-rotation fixing cap (2) into the ilium by screw thread pressing, so that the sharp corner flaps (2b) are pressed into the ilium.

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