Low-Protrusion Offset Spinal Fusion Device

Abstract

The present invention discloses a low-protrusion offset spinal fusion device, comprising a first screw, a connecting seat, a nut and a tightening piece; the first screw is provided with an annular flange; the connecting seat comprises a through portion and a connecting portion, the through portion is provided with a first hole, the connecting portion is offset to one side of the through portion and the height of its top surface is equal to or lower than the height of the top surface of the through portion, and the connecting portion has a recess for a connecting rod to pass therein; the connecting seat is sleeved outside the first screw through the first hole, the first hole abuts against the top of the flange, and the opposite ends of the first screw respectively protrude outside the first hole; the nut is screwed on the first screw and the bottom surface of the nut abuts against the through portion, and the nut and the flange are respectively located on the opposite sides of the first hole; the tightening piece is screwed on the recess to tighten the connecting rod in the recess.

Description

Technical Field

[0001] The invention relates to the field of medical technology, and in particular to a low-protrusion offset spinal fusion device. Background Art

[0002] Pedicle screws generally used for spinal fusion have a multi-axial screw head. The screw head is designed to be multi-piece and requires assembly process errors, which makes the overall volume of the screw head unable to be compressed. The current production limit is a total height of more than 15 mm.

[0003] Generally speaking, the distance from the spinous process to the epidermis of a normal adult is about 32 to 50 mm. After the posterior pedicle screw is implanted, the upper edge of the screw must be greater than 10 to 20 mm from the epidermis. As for infants and patients with spinal deformities, the subcutaneous thickness is less than 20 mm. At the place where the curvature changes, the upper edges of adjacent pedicle screws are likely to interfere with each other.

[0004] Since the overly protruding pedicle screws are not easy to use in the limited back space and are easy to cause friction with the patient's skin, muscles and other soft tissues, it will cause serious discomfort. In other words, for normal adults, infants and young children, patients with insufficient distance between the spine and the epidermis, back deformities and patients who need to lie on their upper body for a long time, the structural design of the pedicle screws currently used in spinal fusion devices is not ideal.

[0005] Therefore, how to develop a "low-protrusion offset spinal fusion device" with a single-axis screw, low height, no discomfort, and no screw interference is an urgent issue to be solved by people in the relevant technical field. Summary of the invention

[0006] In one embodiment, the present invention provides a low-protrusion offset spinal fusion device, which includes: a first screw having an external thread and an annular flange in an axial direction; a connecting seat, which includes: a through portion having a first hole; a connecting portion offset to one side of the through portion, and the height of the top surface of the connecting portion is equal to or lower than the height of the top surface of the through portion, and the connecting portion has a recess for a connecting rod to pass through; the connecting seat is sleeved on the outside of the first screw through the first hole, the first hole abuts against the top of the flange, and the opposite ends of the first screw protrude out of the first hole respectively; a nut screwed on the first screw and the bottom surface of the nut abuts against the through portion, the nut and the flange are respectively located on opposite sides of the first hole; and a tightening member screwed on the recess to tighten the connecting rod in the recess. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic diagram of a combined structure of an embodiment of the present invention;

[0008] Figure 2 for Figure 1 A schematic diagram of the exploded structure of an embodiment;

[0009] Figure 3 for Figure 1 A schematic diagram of a partial cross-section of the combined structure of the embodiment;

[0010] Figure 4 It is a structural schematic diagram of an embodiment of the conical neck of a screw of the present invention;

[0011] Figure 5A and Figure 5B It is a schematic diagram of the structure of different embodiments of the connecting socket of the present invention;

[0012] FIG. 6A to FIG. 6E for Figure 1 Schematic diagram of continuous action of the embodiment installed on the spine;

[0013] Figure 7 The figure is a schematic structural diagram of an embodiment of the present invention in which double screws are provided.

[0014] Explanation of symbols

[0015] 100,100A: Low-Protrusion Offset Spinal Fusion Device

[0016] 10,10A,10B: First screw

[0017] 11,11A,11B: First paragraph

[0018] 12,12A,12B: Second paragraph

[0019] 121: Separation section

[0020] 13: First external thread

[0021] 14: Second external thread

[0022] 15: Flange

[0023] 16: Conical neck

[0024] 161: Taper part

[0025] 162: concave cone

[0026] 163: Center connection

[0027] 20,20A: Connector

[0028] 21,21A: Through-section

[0029] 211: First side

[0030] 212: Side 2

[0031] 213,213A: First hole

[0032] 213B: Second hole

[0033] 214: Radius change junction

[0034] 22,22A: Connecting part

[0035] 221: The third side

[0036] 222: The fourth side

[0037] 223,223A: concave part

[0038] 224: Internal thread

[0039] 23: Chute

[0040] 24: snap-fit ​​parts

[0041] 241: Slide rail

[0042] 242: locking part

[0043] 30: Nut

[0044] 31: Internal thread

[0045] 40: Fastener

[0046] 41: External thread

[0047] 200: Connecting rod

[0048] 300: Spine

[0049] C1, C2: Axial

[0050] D1: Connection diameter

[0051] D2: shaft diameter

[0052] D3: Separation section diameter

[0053] L: Distance

[0054] W1,W2,W3: Outer diameter

[0055] θ: Angle DETAILED DESCRIPTION

[0056] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. The same or similar parts in the drawings are marked with the same reference numerals. The size ratios in the drawings are not drawn in proportion to the actual products, and therefore are not intended to limit the scope of protection of the present invention.

[0057] See also Figure 1 and Figure 2In the illustrated embodiment, the present invention provides a low-protrusion offset spinal fusion device 100, which includes a first screw 10, a connection seat 20, a nut 30 and a tightening member 40. The connection seat 20 provides a connection rod 200 to pass therein.

[0058] See also Figures 2 to 3 As shown, the first screw 10 has a first section 11 and a second section 12 connected along its axial direction C1, the first section 11 is provided with a first external thread 13, and the second section 12 is provided with a second external thread 14. The specifications of the first external thread 13 and the second external thread 14 can be the same or different. In this embodiment, the specifications of the first external thread 13 and the second external thread 14 are different, the first external thread 13 is thicker and the pitch is wider, and the second external thread 14 is thinner and the pitch is narrower, but it is not limited thereto.

[0059] The first screw 10 is provided with an annular flange 15 at a substantially central position in the axial direction C1 thereof. In this embodiment, the flange 15 is disposed between the first section 11 and the second section 12. Specifically, the first section 11 and the second section 12 are disposed on opposite sides of the flange 15. The outer diameter W1 of the flange 15 is greater than the outer diameters W2 and W3 of the first section 11 and the second section 12.

[0060] See also Figure 3 to Figure 4 As shown, the second section 12 is provided with a conical neck 16, which includes a pointed cone portion 161 and a concave cone portion 162. The pointed cone portion 161 protrudes from the axial body surface of the second section 12 toward the first section 11 and gradually shrinks toward the axis of the second section 12. The concave cone portion 162 is concave from the axial body surface of the second section 12 toward the first section 11 and gradually shrinks toward the axis of the second section 12. The taper of the pointed cone portion 161 and the concave size of the concave cone portion 162 are not limited.

[0061] The center of the concave cone portion 162 is connected to the center of the pointed cone portion 161, and a connection diameter D1 is provided at the center connection 163. The second section 12 has an axle body diameter D2, and the connection diameter D1 is smaller than the axle body diameter D2. More specifically, the connection diameter D1 is less than or equal to 1.5 millimeters (mm). The second section 12 forms a separation section 121 above the conical neck 16. In this embodiment, the separation section diameter D3 of the separation section 121 is smaller than the axle body diameter D2, but it is not limited thereto. According to actual needs, the separation section diameter D3 can be greater than, less than or equal to the axle body diameter D2.

[0062] See also Figures 2 to 3 As shown, the connection base 20 includes a through portion 21 and a connection portion 22 .

[0063] The through portion 21 has a first surface 211 and a second surface 212 opposite to each other. The first surface 211 is the top surface of the through portion 21, and the second surface 212 is the bottom surface of the through portion 21. The through portion 21 is provided with a first hole 213 penetrating the first surface 211 and the second surface 212.

[0064] The connecting portion 22 is offset to one side of the through portion 21. The connecting portion 22 has a third surface 221 and a fourth surface 222 opposite to each other, the third surface 221 is the top surface of the connecting portion 22, and the fourth surface 222 is the bottom surface of the connecting portion 22. A recess 223 is provided on the third surface 221 of the connecting portion 22 to allow the connecting rod 200 to pass therethrough, and the recess 223 has an internal thread 224.

[0065] The nut 30 has an inner thread 31 which is screwed to the second outer thread 14 of the first screw 10 and the bottom surface of the nut 30 is against the first surface 211 of the through portion 21. The nut 30 and the flange 15 are respectively located on two opposite sides of the first hole 213, so that the first screw 10 can be locked in the through portion 21. In detail, the first hole 213 has a diameter change in the through portion 21. Figure 3 As shown, the first hole 213 is T-shaped, and the inner diameter of the first hole 213 near the first surface 211 is approximately equal to or slightly larger than the outer diameter W3 of the second section 12, and the inner diameter of the first hole 213 near the second surface 212 is approximately equal to or slightly larger than the outer diameter W1 of the flange 15. The connecting seat 20 is sleeved on the outside of the first screw 10 by one end of the first screw 10 having the second section 12 through the first hole 213, and the first hole 213 abuts against the top of the flange 15, so that the flange 15 can be engaged at the radius change intersection of the first hole 213, and the first screw 10 is locked in the through-portion 21 through the nut 30. However, in other embodiments, the first hole 213 may be a through hole with an unchanged diameter, and the inner diameter of the first hole 213 is approximately equal to or slightly larger than the outer diameter W3 of the second section 12, and the flange 15 with a larger outer diameter W1 can be engaged with the second surface 212 of the connecting seat 20, and the first screw 10 can be locked in the through portion 21 through the nut 30.

[0066] The clamping member 40 has an outer thread 41 that is threadedly engaged with the inner thread 224 of the recess 223 , so that the clamping member 40 is threadedly engaged in the recess 223 to clamp and fix the connecting rod 200 in the recess 223 .

[0067] See also Figure 3 As shown, in this embodiment, the third surface 221 of the connecting portion 22 and the first surface 211 of the through portion 21 are not parallel to each other. Specifically, there is an angle θ between the third surface 221 and the first surface 211, and the angle θ is within a range of 0 to 150 degrees. Through the above-mentioned structure of deflection at an angle, the height of the third surface 221 that sinks obliquely downward is lower than the height of the first surface 211.

[0068] remove Figure 3 In addition to the structure shown, it is also possible to use Figure 5A and Figure 5B Other different structures are shown.

[0069] See also Figure 5A As shown, the third surface 221 is parallel to the first surface 211, and the height of the third surface 221 is equal to the height of the first surface 211, that is, the third surface 221 and the first surface 211 are coplanar. Further, the angle θ between the third surface 221 and the first surface 211 is 0 degrees.

[0070] See also Figure 5B As shown, the third surface 221 and the first surface 211 are parallel to each other, and the third surface 221 and the first surface 211 are not coplanar, that is, there is a distance L between the height of the third surface 221 and the height of the first surface 211, and the size of the distance L is not limited, for example, the distance L is less than or equal to 40 millimeters (mm).

[0071] Figure 3 , Figure 5A and Figure 5B The embodiments illustrate that the connecting socket 20 of the present invention has different implementation forms. However, no matter how the structure changes, the through portion 21 and the connecting portion 22 always adhere to the principle that the height of the third surface 221 (the top surface of the connecting portion 22) is equal to or lower than the height of the first surface 211 (the top surface of the through portion 21).

[0072] See also Figures 1 to 3 As shown, the connection base 20 is provided with a slide slot 23, and two ends of the slide slot 23 in the length direction are respectively facing the first hole 213 and the recess 223. The slide slot 23 is suitable for providing a locking member 24.

[0073] The bottom of the engaging member 24 has a slide rail 241 corresponding to the slide slot 23, so that the engaging member 24 can be engaged in the slide slot 23 through the slide rail 241, but the shape of the slide rail 241 and the slide slot 23 is not limited to the structure shown in the figure. The end of the engaging member 24 facing the nut 30 has a engaging portion 242, and the engaging portion 242 is recessed from the end of the engaging member 24 toward the inside of the engaging member 24.

[0074] When the engaging member 24 is in the released state, Figure 3 As shown, the engaging member 24 can move in the slide slot 23 relative to the first hole 213 and the recess 223. When the engaging member 24 is in the engaged state, as shown in FIG. Figure 1 As shown, two opposite ends of the engaging member 24 respectively abut against the nut 30 and the tightening member 40 , and the engaging portion 242 of the engaging member 24 is engaged with the periphery of the nut 30 .

[0075] It should be noted that the function of the engaging member 24 of the present embodiment is to resist between the first screw 10 and the clamping member 40, and to help strengthen the first screw 10 and the clamping member 40 to be more tightly fastened and not to be distorted. In the case where the first screw 10 and the clamping member 40 are already sufficiently tightly fastened, the user can decide whether to set the engaging member 24 of the present embodiment as needed.

[0076] Please refer to 6A to Fig. 6E As shown, the continuous actions of the present invention installed on the spine are explained.

[0077] See also Fig. 6A As shown, first, the first section 11 of the first screw 10 is locked into the spine 300 according to the required angle and the required position, and then the connecting seat 20 is sleeved on the outside of the first screw 10 through the first hole 213 by the end of the first screw 10 having the second section 12, and then the nut 30 is inserted.

[0078] See also Figure 6B As shown, the radius change junction 214 of the first hole 213 of the connecting seat 20 abuts against the top of the flange 15, the nut 30 is screwed on the second outer thread 14 of the first screw 10 and the bottom surface of the nut 30 abuts against the first surface 211 of the through portion 21. At this time, the nut 30 and the flange 15 are respectively located on the opposite sides of the first hole 213, so that the first screw 10 can be locked in the first hole 213, and the opposite ends of the first section 11 and the second section 12 of the first screw 10 protrude out of the first hole 213. At this time, the engaging member 24 is in a released state and has not yet contacted the nut 30.

[0079] See also Figure 6C As shown in FIG. 1 , the separation section 121 of the first screw 10 located above the conical neck 16 is broken off from the conical neck 16. Since the conical neck 16 has a special structural size design, it can be Figure 4 The center connection 163 is shown broken without producing a protruding burr.

[0080] See also Fig.6D As shown, the connecting rod 200 is then placed into the recess 223 , and the engaging member 24 is pushed toward the first screw 10 , so as to facilitate screwing the tightening member 40 into the recess 223 .

[0081] See also Fig. 6E As shown in FIG. 1 , the clamping member 40 clamps the connecting rod 200 in the recess 223. At this time, the opposite ends of the engaging member 24 respectively abut against the nut 30 and the clamping member 40. In this way, the installation of a vertebra 300 is completed. In one embodiment, if multiple low-protrusion offset spinal fusion devices 100 are to be installed, the steps are repeated. FIG. 6A to FIG. 6C Finally, the single connecting rod 200 is uniformly placed in the recess 223 to perform the subsequent FIG. 6D to FIG. 6E By performing the steps, a plurality of low-protrusion offset spinal fusion devices 100 are installed one by one on each vertebra 300 and connected in series by a connecting rod 200 having a certain length.

[0082] The separation section 121 is used for the user to grasp it, so as to facilitate screwing the first screw 10 into the spine 300. After the low-protrusion offset spinal fusion device 100 is assembled, the separation section 121 can be broken off and discarded to reduce the overall height.

[0083] See also Figure 7 As shown, this embodiment discloses an implementation mode with double screws. A low-protrusion offset spinal fusion device 100A comprises a first screw 10A, a second screw 10B, a connecting seat 20A, a nut 30 and a tightening member 40 .

[0084] The structure of the first screw 10A and the second screw 10B is Figure 3 The structures of the first screws 10 are substantially the same. The first screw 10A has a first section 11A and a second section 12A opposite to each other along its axial direction C1. The second screw 10B has a first section 11B and a second section 12B opposite to each other along its axial direction C2. In this embodiment, the length of the first section 11A of the first screw 10A is greater than the length of the first section 11B of the second screw 10B, but it is not limited thereto, and the sizes of the first screw 10A and the second screw 10B can be designed according to actual needs.

[0085] The connection base 20A includes a through portion 21A and a connection portion 22A. Figure 3 The connecting base 20 of FIG. 20A is similar to the connecting base 20 of FIG. 20A, but it should be noted that the through portion 21A of the connecting base 20A has two holes, namely a first hole 213A and a second hole 213B. A first screw 10A is disposed in the first hole 213A, and a second screw 10B is disposed in the second hole 213B.

[0086] In this embodiment, the central axis of the first hole 213A and the second hole 213B (i.e., the axis C1 and C2) are designed with different directions. After the first screw 10A and the second screw 10B are respectively locked in the first hole 213A and the second hole 213B, the axis C1 and C2 of the first screw 10A and the second screw 10B intersect, that is, the central axis of the first hole 213A and the second hole 213B intersect. In other words, the user can design the direction of the central axis of the first hole 213A and the second hole 213B as needed to provide a double locking force when set in the spine 300.

[0087] The connecting rod 200 is placed into the recess 223A of the connecting portion 22A, and the tightening member 40 is screwed into the recess 223A to tighten the connecting rod 200 in the recess 223, thereby completing the installation of a vertebra 300. If multiple low-protrusion offset spinal fusion devices 100A are to be installed, the steps of, for example, FIG. 6A to FIG. 6C Finally, the single connecting rod 200 is uniformly placed in the recess 223A to perform the subsequent FIG. 6D to FIG. 6EBy performing the steps, a plurality of low-protrusion offset spinal fusion devices 100A are installed one by one on each vertebra 300 and connected in series by a connecting rod 200 having a certain length.

[0088] In summary, the low-protrusion offset spinal fusion device provided by the present invention is a low-protrusion fixation system for fixing the stability of the vertebral body. The complicated screw head design is improved to sink the connecting part suitable for setting the connecting rod and offset it to the space on the front side of the spine to provide a corrective force, reduce the overall height of the bone surface protruding to the dorsal side, and avoid excessive protrusions rubbing against the patient's skin, muscles and other soft tissues. In addition, the 360-degree rotatable connecting seat provides a function of multi-axial adjustment of the connecting rod to meet the patient's anatomical space. The main clinical applications, such as but not limited to, the correction and fixation of multiple vertebrae of the lumbar sacral spine (L1~S1), can be used to treat congenital vertebral dysplasia, kyphosis, deformity and spinal nerve compression, and provide spinal fusion surgery after spinal surgery.

[0089] Although the present invention is disclosed in conjunction with the above embodiments, they are not intended to limit the present invention. Any person with ordinary knowledge in the technical field may make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the attached claims.

Claims

1. A low-protrusion offset spinal fusion device, characterized in that: Include: The first screw has an external thread and is provided with an annular flange in the axial direction; A connecting seat, comprising: The penetration portion is provided with a first hole; The connecting portion is offset to one side of the through portion, and the height of the top surface of the connecting portion is equal to or lower than the height of the top surface of the through portion, and the connecting portion has a recessed portion for the connecting rod to pass through; the connecting seat is sleeved on the outside of the first screw through the first hole, the first hole abuts against the top of the flange, and the opposite ends of the first screw protrude out of the first hole respectively; A nut, screwed on the first screw and with the bottom surface of the nut against the through-portion, the nut and the flange being located on two opposite sides of the first hole respectively; as well as The clamping piece is screwed into the recess to clamp the connecting rod in the recess.

2. The low-protrusion offset spinal fusion device as described in claim 1, wherein the first screw has a first section and a second section connected along the axial direction, the first section is provided with a first external thread, the second section is provided with a second external thread, the flange is arranged between the first section and the second section, and the outer diameter of the flange is greater than the outer diameters of the first section and the second section.

3. The low-protrusion offset spinal fusion device as claimed in claim 2, wherein the first hole is formed by an end of the first screw having the second section being sleeved outside the first screw, and the first hole abuts against the top of the flange.

4. The low-protrusion offset spinal fusion device of claim 2, wherein the second section has a tapered neck, comprising: A pointed cone portion protrudes from the shaft body surface of the second section toward the first section and gradually contracts toward the axis of the second section; The concave cone portion is concave from the shaft body surface of the second section toward the first section and gradually shrinks toward the axis of the second section. The center of the concave cone portion and the center of the pointed cone portion have a connecting diameter. The second section has a shaft body diameter, and the connecting diameter is smaller than the shaft body diameter.

5. The low-protrusion offset spinal fusion device of claim 4, wherein the connection diameter is less than or equal to 1.5 millimeters (mm). 6 . The low-protrusion offset spinal fusion device as claimed in claim 2 , wherein the nut is screwed onto the second outer thread of the first screw.

7. The low-protrusion offset spinal fusion device as described in claim 1, wherein the penetrating portion has a first surface and a second surface relative to each other, the first surface is the top surface of the penetrating portion, the second surface is the bottom surface of the penetrating portion, and the first hole penetrates the first surface and the second surface; and the connecting portion has a third surface and a fourth surface relative to each other, the third surface is the top surface of the connecting portion, the fourth surface is the bottom surface of the connecting portion, the height of the third surface is equal to or lower than the height of the first surface, and the recess is arranged on the third surface.

8. The low-protrusion offset spinal fusion device as claimed in claim 7, wherein the third surface and the first surface are not parallel to each other, and an angle is formed between the third surface and the first surface, and the angle is within a range of 0 to 150 degrees.

9. The low-protrusion offset spinal fusion device as claimed in claim 7, wherein the third surface is parallel to the first surface, and the third surface is not coplanar with the first surface, and there is a distance between the height of the third surface and the height of the first surface, and the distance is less than or equal to 40 millimeters (mm).

10. The low-protrusion offset spinal fusion device as described in claim 1, wherein the connecting seat is provided with a slide groove, and the two ends of the slide groove in the length direction are respectively facing the first hole and the recess, and the slide groove is provided with a clamping piece; when the clamping piece is in a released state, the clamping piece can move in the slide groove relative to the first hole and the recess; when the clamping piece is in a clamping state, the opposite ends of the clamping piece respectively abut against the nut and the tightening piece.

11. The low-protrusion offset spinal fusion device as described in claim 10, wherein the end of the engaging member facing the nut has an engaging portion, the engaging portion is recessed from the end of the engaging member toward the inside of the engaging member, and when the engaging member is in the engaging state, the engaging portion is engaged with the periphery of the nut.

12. The low-protrusion offset spinal fusion device as claimed in claim 1, wherein the through portion further has a second hole, a second screw is disposed in the second hole, and the first hole and the second hole intersect in a central axial direction.

13. The low-protrusion offset spinal fusion device as claimed in claim 1, wherein the recess has an internal thread, and the tightening member has an external thread that is threadedly engaged with the internal thread of the recess.

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