A sacral screw fixation structure

Abstract

The present invention discloses a sacral screw fixation structure, belonging to the technical field of orthopedic implants. The sacral screw fixation structure includes a screw seat, a main screw and a titanium rod. The screw seat is provided with a reinforcing plate extending horizontally. The reinforcing plate is provided with a universal locking hole, and an auxiliary screw is arranged in the universal locking hole. The main screw and the auxiliary screw are both sacral screws and are arranged staggeredly. By setting a horizontally extending reinforcing plate and using the auxiliary screw for additional fixation, the whole fixation structure is not easy to loosen and dislodge during the operation process, solving the problem of weak holding force of a single sacral screw in the prior art. Moreover, the auxiliary screw in the present invention is detachable, with high safety and convenient operation.

Description

Technical Field

[0001] The invention relates to the technical field of orthopedic implants, in particular to a sacral screw fixing structure. Background Art

[0002] Lumbar spine fusion has always been a challenging area in spinal surgery. The complex local anatomy, unique biomechanical properties, and poor bone quality of the sacrum are all reasons why lumbar spine fusion is difficult.

[0003] Currently, in sacral fracture fixation surgery, the sacrum is usually fixed with only one screw. For patients with osteoporosis, the holding force of a single screw is weak, and there is a problem of insufficient screw firmness. Therefore, it is necessary to provide a fixation structure suitable for the sacrum area that can enhance the fixation strength. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a sacral screw fixing structure, which is suitable for the sacral region and can enhance the fixing strength.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A sacral screw fixing structure comprises a screw seat, a main screw and a titanium rod, wherein:

[0007] The screw seat has an axial through hole, the lower end of which is closed, the main screw comprises a nail body and a head located at the upper end of the nail body and having a circumferential size larger than the nail body, the nail body of the main screw passes through the axial through hole of the screw seat, and the head of the main screw is stopped by the closed end of the screw seat to prevent the main screw from coming out of the lower end of the screw seat;

[0008] A pair of openings are provided on the side walls of the screw seat so that a U-shaped groove is formed at the upper end of the screw seat, and internal threads are provided on both side walls of the U-shaped groove. The titanium rod and the screw plug that cooperates with the internal threads to press the titanium rod and the main screw into the screw seat are sequentially provided in the U-shaped groove above the head of the main screw;

[0009] The screw seat is provided with a transversely extending reinforcing plate, the reinforcing plate is provided with a universal locking hole, the universal locking hole is provided with an auxiliary nail, and the main screw and the auxiliary nail are both sacral nails and are staggered.

[0010] Furthermore, a pair of holding arms for connecting and cooperating with the screw base are provided on the reinforcing plate. Grooves are symmetrically provided on one side of the two holding arms facing each other. The symmetrically arranged grooves enclose a jack for inserting the side wall of the U-shaped groove. On one side of the two holding arms facing each other, protrusions extending into the U-shaped groove are also symmetrically provided. The upper end surfaces of the pair of protrusions form a pressing and cooperating surface for cooperating with the plug to press and fix the reinforcing plate in the screw base. The side surfaces of the pair of protrusions are a blocking and cooperating surface for cooperating with the side wall of the U-shaped groove to prevent the reinforcing plate from disengaging from the side of the screw base.

[0011] The pair of holding arms is a deformable structure and there is a moving gap between them, so as to be clamped and moved by the instrument after being inserted into the screw base to tightly hold and fix the screw base.

[0012] Furthermore, the reinforcing plate is Z-shaped and includes an upper cross plate, a vertical plate and a lower cross plate. The holding arms are arranged on the upper cross plate, and the universal locking holes are arranged on the lower cross plate. The upper cross plate is located above the titanium rod. The upper end surfaces of the protrusions arranged on the holding arms are directly in pressing cooperation with the plug, and the lower end surfaces of the protrusions are in pressing cooperation with the titanium rod.

[0013] Furthermore, the lower end surface of the protrusion is an arc-shaped structure that cooperates with the cylindrical surface of the titanium rod.

[0014] Furthermore, a pair of first instrument clamping grooves are provided on the outer side wall of the U-shaped groove, and a buckle cooperating with the first instrument clamping groove is provided on the surface of the vertical plate of the reinforcing plate facing the U-shaped groove.

[0015] And / or, a pair of second instrument clamping grooves are provided on the front and rear end surfaces of the outer side wall of the U-shaped groove. A rib cooperating with the second instrument clamping groove is provided on the holding arm of the reinforcing plate. The holding arm is a deformable structure. After the holding arm is installed on the U-shaped groove, it is clamped and deformed by the instrument so that the rib enters the second instrument clamping groove to be firmly fixed to the U-shaped groove.

[0016] Furthermore, the holding arm is in tight cooperation with one side wall of the U-shaped groove on the screw base. A pair of grooves for inserting one side wall of the U-shaped groove are provided on the pair of holding arms, and the protrusions are arranged at the ends of the holding arms.

[0017] Or, the holding arm is in tight cooperation with the two side walls of the U-shaped groove on the screw base. Two pairs of grooves for inserting the two side walls of the U-shaped groove are provided on the pair of holding arms, and the protrusions are arranged in the middle of the holding arms.

[0018] Furthermore, the reinforcing plate is Z-shaped. A lower opening for buckling on the top of the screw base is provided on one side cross plate of the reinforcing plate, and a through hole is provided in the lower opening.

[0019] The plug includes a first threaded section at the lower part and a second threaded section at the upper part. The first threaded section is used for threadedly connecting the two side walls of the U-shaped groove. The outer diameter of the second threaded section is smaller than that of the first threaded section. The second threaded section is used for passing through the through hole on the reinforcing plate and fixing the reinforcing plate on the screw seat by a fixing nut.

[0020] A pair of instrument clamping grooves are provided on the outer side wall of the U-shaped groove. On the side of the middle vertical plate of the reinforcing plate facing the U-shaped groove, there are buckles that cooperate with the instrument clamping grooves.

[0021] Further, a pair of instrument clamping grooves are provided on the outer side wall of the U-shaped groove.

[0022] The reinforcing plate is Z-shaped. On one side horizontal plate of the reinforcing plate, there is a lower opening for buckling on the top of the screw seat. The edge of the lower opening is provided with a first buckle that cooperates with one side instrument clamping groove. On the side of the middle vertical plate of the reinforcing plate facing the U-shaped groove, there is a second buckle that cooperates with the other side instrument clamping groove. The reinforcing plate is buckled and clamped on the screw seat through the first buckle and the second buckle.

[0023] Further, the universal locking holes are located on the other side horizontal plate of the reinforcing plate and the number is two. The auxiliary nails in the universal locking holes are symmetrically distributed along the axis.

[0024] Further, the reinforcing plate is a straight horizontal plate. One end of the reinforcing plate and the bottom of the screw seat are of an integral structure. The other end of the reinforcing plate is also provided with a screw seat, a main screw and a titanium rod. The two ends of the reinforcing plate have the same structural form.

[0025] The present invention has the following beneficial effects:

[0026] The sacral screw fixation structure of the present invention, by providing a horizontally extending reinforcing plate and using auxiliary nails for additional fixation, makes the whole fixation structure not easy to loosen and come off during the operation, solves the problem of weak holding force of a single sacral screw in the prior art, and the auxiliary nails in the present invention are detachable, with high safety and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of an embodiment of the sacral screw fixation structure of the present invention, where (a) is a sectional view and (b) is a three-dimensional view.

[0028] Figure 2 It is a schematic structural diagram of another embodiment of the sacral screw fixation structure of the present invention, where (a) is a sectional view and (b) is a three-dimensional view and the reinforcing plate is shown separately.

[0029] Figure 3Schematic diagram of the structure of another embodiment of the sacral screw fixing structure of the present invention, wherein (a) is a cross-sectional view and (b) is a stereoscopic view;

[0030] Figure 4 Schematic diagram of the structure of another embodiment of the sacral screw fixing structure of the present invention, wherein (a) is a stereoscopic diagram, and (b) is a structural diagram after removing the auxiliary screw in (a);

[0031] Figure 5 Schematic diagram of the structure of another embodiment of the sacral screw fixing structure of the present invention, wherein (a) is a cross-sectional view and (b) is a stereoscopic view;

[0032] Figure 6 Schematic diagram of the structure of another embodiment of the sacral screw fixing structure of the present invention, wherein (a) is a cross-sectional view and (b) is a stereoscopic view. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0034] The present invention provides a sacral screw fixing structure, such as Figure 1-6 As shown, it includes a screw seat 1, a main screw 2 and a titanium rod 3, wherein:

[0035] The screw seat 1 has an axial through hole, the lower end of the axial through hole is closed, the main screw 2 includes a nail body and a head located at the upper end of the nail body and having a circumferential size larger than the nail body, the nail body of the main screw 2 passes through the axial through hole of the screw seat 1, and the head of the main screw 2 is stopped by the closed end of the lower end of the screw seat 1 to prevent the main screw 2 from coming out of the lower end of the screw seat 1; in specific implementation, the screw seat 1 can be a universal screw seat, the main screw 2 can be a universal ball nail, the universal ball nail can include a solid nail and a hollow nail, and the hollow nail is divided into two types: containing an injectable cement hole and not containing an injectable cement hole;

[0036] A pair of openings are provided on the side wall of the screw seat 1 so that a U-shaped groove for placing the titanium rod 3 is formed at the upper end of the screw seat 1. The two side walls of the U-shaped groove are provided with internal threads. The titanium rod 3 and screw plugs 5, 5' (also called threaded pressure nails) that cooperate with the internal threads to press the titanium rod 3 and the main screw 2 in the screw seat 1 are arranged in sequence in the U-shaped groove. In order to improve the fixing firmness of the main screw 2, a pressure nail washer 4 can also be arranged between the head of the main screw 2 and the titanium rod 3 in the U-shaped groove;

[0037] The screw seat 1 is provided with transversely extending reinforcing plates 6, 6', 6", 6"', and the reinforcing plates 6, 6', 6", 6"' are provided with universal locking holes 7 (spherical holes), and auxiliary nails 8 are provided in the universal locking holes 7. The main screws 2 and the auxiliary nails 8 are both sacral nails and are staggered (i.e., non-parallel arrangements to improve the fixing strength).

[0038] The sacral screw fixation structure of the present invention is applied to spinal internal fixation surgery, especially suitable for sacral fixation surgery. Its main feature is double screws and detachable. Specifically, by setting a horizontally extending reinforcing plate and using auxiliary screws for additional fixation, the entire fixation structure is not easily loosened and displaced during the operation, solving the problem of weak holding force of a single sacral screw in the prior art. Moreover, the auxiliary screws in the present invention are detachable, with high safety and convenient operation.

[0039] According to different structures and installation forms of the reinforcing plate, the present invention can specifically have the following embodiments.

[0040] Embodiment 1

[0041] As Figure 1 shown, the reinforcing plate 6 is Z-shaped. On one side horizontal plate of the reinforcing plate 6 (the left side in the illustrated embodiment), there is a lower opening 61 for buckling on the top of the screw seat 1. For the convenience of installation, the size of the lower opening 61 can be slightly larger than the width size of both side walls of the screw seat 1; a through hole 62 is provided in the lower opening 61 to cooperate with the plug 5; the universal locking hole 7 is located on the other side horizontal plate of the reinforcing plate 6 and the number is one.

[0042] The plug 5 includes a first threaded section 51 at the lower part and a second threaded section 52 at the upper part. The first threaded section 51 is used for threaded connection with both side walls of the U-shaped groove, and the second threaded section 52 is used for passing through the through hole 62 on the reinforcing plate 6 and fixing the reinforcing plate 6 on the screw seat 1 through the fixing nut 9.

[0043] In this embodiment, the reinforcing plate 6 is Z-shaped, which can greatly reduce the notch at the auxiliary screw 8; the reinforcing plate 6 is first buckled on the screw seat 1 and then fixed by pressing with the fixing nut 9. This fixing method is firm and reliable.

[0044] The outer diameter of the second threaded section 52 is preferably smaller than the outer diameter of the first threaded section 51, so that a smaller fixing nut 9 can be used, reducing the structural volume and tissue irritation. Further, a pair of instrument clamping grooves 11 can be provided on the outer side wall of the U-shaped groove, and a buckle (not shown) matching with the instrument clamping grooves 11 can be provided on the surface of the middle vertical plate of the reinforcing plate 6 facing the U-shaped groove. In this way, when the reinforcing plate 6 is buckled on the universal screw seat 1, the buckle can play a clamping and fixing role, and then it is fixed by the fixing nut 9, making the overall fixing effect more reliable.

[0045] Embodiment 2

[0046] Embodiment 2 is not shown and can be appropriately referred to Figure 1。In this embodiment, a pair of instrument clamping grooves 11 are provided on the outer side wall of the U-shaped groove; the reinforcing plate 6 is Z-shaped, and a lower opening 61 for buckling on the top of the screw seat 1 is provided on one side horizontal plate of the reinforcing plate 6. A first buckle (not shown, which can be various common protrusion structures in the art, specifically, for example, a barb) is provided at the edge of the lower opening 61. A second buckle (not shown, which can be various common protrusion structures in the art) is provided on the surface of the middle vertical plate of the reinforcing plate 6 facing the U-shaped groove and cooperating with the other instrument clamping groove 11. The reinforcing plate 6 is buckled and clamped on the screw seat 1 through the first buckle and the second buckle. In this way, the reinforcing plate 6 is fixed on the screw seat 1 by double-sided clamping, without the need to be fixed by the fixing nut 9, and the fixing is simple and reliable, and it is convenient to disassemble; at this time, the plug can be Figure 5 or Figure 6 the conventional plug 5' in

[0047] Embodiment 3

[0048] As shown in Figure 2 this embodiment, it is basically the same as the structure of Embodiment 1 shown in Figure 1 , except that the number of universal locking holes 7 is two, and the auxiliary nails 8 in the universal locking holes 7 are symmetrically distributed along the axis, thus forming a detachable three-screw sacral nail structure.

[0049] Embodiment 4

[0050] As shown in Figure 3 this embodiment, a pair of holding arms 61' for connecting and cooperating with the screw seat 1 are provided on the reinforcing plate 6'. Grooves are symmetrically provided on the opposite sides of the two holding arms 61', and the symmetrically arranged grooves enclose an insertion hole 62' for inserting the side wall of the U-shaped groove. For the convenience of installation, the size of the insertion hole 62' can be slightly larger than the size of the side wall of the U-shaped groove; protrusions 63' extending into the U-shaped groove are also symmetrically provided on the opposite sides of the two holding arms 61'. The upper end surfaces of the pair of protrusions 63' constitute a pressing and cooperating surface for cooperating with the plug 5' to press and fix the reinforcing plate 6' in the screw seat 1, and the side surfaces of the pair of protrusions 63' are a stop and cooperating surface for cooperating with the side wall of the U-shaped groove to prevent the reinforcing plate from disengaging from the side of the screw seat 1;

[0051] The pair of holding arms 61' are of deformable structure and there is a moving gap between them, so as to be clamped and moved by an instrument after being inserted into the screw seat 1 to tightly hold and fix the screw seat 1.

[0052] Furthermore, the reinforcing plate 6' can be Z-shaped, including an upper horizontal plate, a vertical plate and a lower horizontal plate. The holding arms 61' are provided on the upper horizontal plate, the number of universal locking holes 7 provided on the lower horizontal plate is one, the upper horizontal plate is located above the titanium rod 3, the upper end surface of the protrusion 63' provided on the holding arm 61' is directly pressed and cooperated with the plug 5', and the lower end surface of the protrusion 63' is pressed and cooperated with the titanium rod 3.

[0053] It can be understood that the jack 62' inside the arm 61' is an open hole, not in a closed form. At the same time, the arm is set as a deformable structure, so that the size of the jack 62' can be designed to be larger than the size of the side wall of the U-shaped groove. This is convenient for installation and can be fixed by clamping front and back after installation without affecting the installation stability. To ensure the firm fixation of the titanium rod 3, the lower end face of the protrusion 63' is preferably an arc structure that fits the cylindrical surface of the titanium rod 3.

[0054] In this embodiment, the reinforcing plate 6' is sleeved on one side wall of the U-shaped groove of the screw seat 1, and the part of the reinforcing plate 6' located inside the screw seat 1 is pressed and fixed by a plug. Compared with Embodiment 1, the vertical height at the screw seat 1 is greatly reduced, thereby reducing the height of the notch line of the entire fixing structure. Moreover, the left end of the reinforcing plate 6' (i.e., the side of the protrusion 63') presses on the upper side of the titanium rod 3, which can reduce the vertical height of the titanium rod 3. In this way, when the fixing structure is in use, the titanium rod 3 can closely adhere to the surface of the human bone, reducing the external protrusion height after the fixing structure is installed, thereby reducing the impact on other parts of the human body after the fixing structure is implanted. The combination of the setting of the left end position of the reinforcing plate 6' and the overall Z-shaped structure design simultaneously reduces the vertical height of the titanium rod and the notch line height of the auxiliary nail on the right side.

[0055] In this embodiment, a pair of first instrument clamping grooves 11' can be provided on the outer side wall of the U-shaped groove, and a buckle (not shown) that cooperates with the first instrument clamping grooves 11' is provided on the side of the vertical plate of the reinforcing plate 6' facing the U-shaped groove to play a role of clamping and fixing;

[0056] And / or, a pair of second instrument clamping grooves 12' are provided on the front and rear end faces of the outer side wall of the U-shaped groove, and a rib (not shown) that cooperates with the second instrument clamping grooves 12' is provided on the arm 61' of the reinforcing plate 6'. The arm 61' is a deformable structure. After the arm 61' is installed on the U-shaped groove, it is deformed by the instrument clamping so that the rib enters the second instrument clamping groove 12' to be firmly fixed to the U-shaped groove.

[0057] In Figure 3 In the shown embodiment, the arm 61' is tightly clamped and fitted with one side wall of the U-shaped groove on the screw seat 1. A pair of grooves for inserting one side wall of the U-shaped groove are provided on the pair of arms 61', and the protrusion 63' is provided at the end of the arm 61'; it can be understood that there is an obvious variation method, that is: the arm is tightly clamped and fitted with two side walls of the U-shaped groove on the screw seat, and two pairs of grooves for inserting two side walls of the U-shaped groove are provided on the pair of arms, and the protrusion is provided in the middle of the arm. Under this structural variation method, the reinforcing plate can also play a good fixing role.

[0058] Embodiment 5

[0059] In this embodiment, such asFigure 4 As shown, it is Figure 3 basically the same as the structure of Embodiment 4 shown. The difference is that the number of universal locking holes 7 is two, and the auxiliary pins 8 in the universal locking holes 7 are symmetrically distributed along the axis, thus forming a detachable three-screw sacral nail structure.

[0060] Embodiment 6

[0061] In this embodiment, as Figure 5 shown, the reinforcing plate 6” is a horizontal plate in the shape of a straight line, and one end of the reinforcing plate 6” is an integral structure with the bottom of the screw seat 1.

[0062] Embodiment 7

[0063] In this embodiment, as Figure 6 shown, it is Figure 5 basically the same as the structure of Embodiment 6 shown. The difference is that screw seats 1’, main screws 2’, titanium rods 3’, pressing washer and plug etc. are also provided at the other end of the reinforcing plate 6”’. The two ends of the reinforcing plate 6”’ have the same structural form. At this time, the auxiliary pin is the main screw 2’.

[0064] Both screws of this structure are main screws, and the direction of the screws can be determined according to the actual situation during the operation. This structure can be used when connecting double rods. The reinforcing plate 6”’ between the double screw seats and the double screw seats are fixedly connected / integral structures.

[0065] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A sacral screw fixation structure, comprising a screw seat, a main screw and a titanium rod, It is characterized in that The screw seat has an axial through hole, the lower end of which is closed, the main screw comprises a nail body and a head located at the upper end of the nail body and having a circumferential size larger than the nail body, the nail body of the main screw passes through the axial through hole of the screw seat, and the head of the main screw is stopped by the closed end of the screw seat to prevent the main screw from coming out of the lower end of the screw seat; A pair of openings are provided on the side walls of the screw seat so that a U-shaped groove is formed at the upper end of the screw seat, and internal threads are provided on both side walls of the U-shaped groove. The titanium rod and the screw plug that cooperates with the internal threads to press the titanium rod and the main screw into the screw seat are sequentially provided in the U-shaped groove above the head of the main screw; The screw seat is provided with a transversely extending reinforcement plate, the reinforcement plate is provided with a universal locking hole, the universal locking hole is provided with an auxiliary nail, the main screw and the auxiliary nail are both sacral nails and are staggered; The reinforcing plate is provided with a pair of arms for connecting and cooperating with the screw seat, and grooves are symmetrically provided on opposite sides of the two arms, and the symmetrically arranged grooves surround a plug hole for the side wall of the U-shaped groove to be inserted, and the opposite sides of the two arms are also symmetrically provided with protrusions extending into the U-shaped groove, and the upper end surfaces of the pair of protrusions constitute a pressing fitting surface that cooperates with the screw plug to press and fix the reinforcing plate in the screw seat, and the side surfaces of the pair of protrusions are stop fitting surfaces that cooperate with the side walls of the U-shaped groove to prevent the reinforcing plate from escaping from the side of the screw seat; The pair of arms are deformable structures and have a moving gap between them, so that after being inserted into the screw seat, they can be clamped and moved by an instrument to clamp and fix the screw seat.

2. The sacral screw fixing structure according to claim 1, It is characterized in that The reinforcing plate is Z-shaped, including an upper horizontal plate, a vertical plate and a lower horizontal plate. The arm is arranged on the upper horizontal plate, the universal locking hole is arranged on the lower horizontal plate, the upper horizontal plate is located above the titanium rod, the upper end surface of the protrusion arranged on the arm is directly pressed together with the screw plug, and the lower end surface of the protrusion is pressed together with the titanium rod.

3. The sacral screw fixing structure according to claim 2, It is characterized in that The lower end surface of the protrusion is an arc-shaped structure matched with the cylindrical surface of the titanium rod.

4. The sacral screw fixing structure according to claim 2, It is characterized in that A pair of first instrument clamping grooves are provided on the outer side wall of the U-shaped groove, and a buckle matching with the first instrument clamping groove is provided on the vertical plate of the reinforcing plate on a surface facing the U-shaped groove; And / or, a pair of second instrument clamping grooves are provided on the front and rear end surfaces of the outer side wall of the U-shaped groove, and a convex strip matching the second instrument clamping groove is provided on the arm of the reinforcing plate. The arm is a deformable structure. After the arm is installed on the U-shaped groove, it is clamped and deformed by the instrument so that the convex strip enters the second instrument clamping groove and is firmly fixed to the U-shaped groove.

5. The sacral screw fixing structure according to any one of claims 1 to 4, It is characterized in that The holding arms are tightly engaged with one side wall of the U-shaped groove on the screw seat. A pair of grooves for inserting one side wall of the U-shaped groove are provided on the pair of holding arms, and the protrusions are arranged at the ends of the holding arms. Alternatively, the holding arms are tightly engaged with two side walls of the U-shaped groove on the screw seat. Two pairs of grooves for inserting two side walls of the U-shaped groove are provided on the pair of holding arms, and the protrusions are arranged in the middle of the holding arms.

6. The sacral screw fixation structure according to any one of claims 2-4, characterized in that the number of the universal locking holes is two, and the auxiliary screws in the universal locking holes are symmetrically distributed along the axis.

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