Intervertebral distraction tools

Abstract

The present invention provides an intervertebral distraction tool, comprising: an upper end plate; a lower end plate; an abutment member abutting between the first end of the upper end plate and the first end of the lower end plate; a sleeve, the first end of the sleeve abutting between the second end of the upper end plate and the second end of the lower end plate; a driving rod passing through the sleeve and rotatably arranged, the first end of the driving rod is connected to the abutment member, the driving rod rotates and drives the abutment member to approach or move away from the sleeve along the axial direction of the sleeve; the anti-overload connection assembly has a transmission state and a relative rotation state in sequence when rotating; when the anti-overload connection assembly is in the transmission state, the anti-overload connection assembly drives the driving rod to rotate; when the anti-overload connection assembly is in the relative rotation state, the driving rod stops rotating to keep the distance between the upper end plate and the lower end plate unchanged. The technical solution of the present application effectively solves the problem in the related art that the intervertebral distraction force is easily too large or too small, making the operation of intervertebral distraction more troublesome.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an intervertebral distraction tool. Background Art

[0002] As society continues to age, more and more people are suffering from spinal injuries, spinal dislocations, and other diseases. Currently, the most effective treatment is to use a pedicle fixation system to reposition the slipped vertebrae and perform intervertebral fusion fixation, ultimately restoring the normal sagittal sequence and force relationship of the spine and relieving the traction and compression on the nerve roots. For patients with obvious spinal dislocation, the intervertebral space needs to be expanded during surgery, and the slipped vertebrae need to be repositioned or a prosthesis needs to be implanted in the intervertebral space.

[0003] In the related art, when the intervertebral space is expanded, the method used is to first drive pedicle screws into the pedicles of two adjacent vertebrae, and then expand the intervertebral space by applying force to the tail of the pedicle screw. However, when the patient's bone quality is poor and the intervertebral expansion force is large, it is easy to loosen the interface of the vertebral autologous bone, easily damage the vertebral autologous bone, and affect the stability of the vertebral body after reduction or implantation of the prosthesis. When the intervertebral expansion force is small, it is not convenient to reduce the slipped vertebral body and to insert the prosthesis.

[0004] Thus, since the force application standards of the operators cannot be unified, the intervertebral distraction force is easily too large or too small, requiring multiple observations and adjustments, making the intervertebral distraction operation more troublesome. Summary of the invention

[0005] The main purpose of the present invention is to provide an intervertebral distraction tool to solve the problem in the related art that the intervertebral distraction force is easily too large or too small, making the intervertebral distraction operation more troublesome.

[0006] In order to achieve the above-mentioned purpose, the present invention provides an intervertebral distraction tool, comprising: an upper end plate; a lower end plate, which is arranged opposite to the upper end plate and is located below the upper end plate; an abutment member, which abuts between a first end of the upper end plate and a first end of the lower end plate; a sleeve, wherein the first end of the sleeve abuts between a second end of the upper end plate and a second end of the lower end plate; a driving rod, which passes through the sleeve and is rotatably arranged, wherein the first end of the driving rod is connected to the abutment member, the driving rod rotates and drives the abutment member to approach or move away from the sleeve along the axial direction of the sleeve, and the abutment member and the first end of the sleeve jointly push the upper end plate and the lower end plate to move the upper end plate toward or away from the sleeve. The plate and the lower end plate move away from or approach each other; an anti-overload connection component is connected to the second end of the driving rod and is located on the outside of the sleeve, driving the anti-overload connection component to rotate to drive the driving rod to rotate; wherein, the anti-overload connection component has a transmission state and a relative rotation state in sequence when rotating; when the anti-overload connection component is in the transmission state, the anti-overload connection component drives the driving rod to rotate so that the distance between the upper end plate and the lower end plate can be adjusted; when the anti-overload connection component is in the relative rotation state, the anti-overload connection component rotates relative to the driving rod, and the driving rod stops rotating so that the distance between the upper end plate and the lower end plate remains unchanged.

[0007] Furthermore, the anti-overload connection assembly includes a shell, an anti-overload connection piece arranged in the shell, and a knob rotatably arranged on the shell, and the anti-overload connection piece is connected between the knob and the driving rod; when the knob drives the anti-overload connection piece to rotate to drive the driving rod to rotate, the anti-overload connection assembly is in a transmission state; when the knob drives the anti-overload connection piece and the driving rod to rotate relative to each other, the driving rod stops rotating, and the anti-overload connection assembly is in a relative rotation state.

[0008] Furthermore, the anti-overload connecting member includes a spring fixedly connected to the knob, a first transmission member fixedly connected to the spring, and a second transmission member fixedly connected to the driving rod; the knob drives the spring to rotate, and the first transmission member cooperates with the second transmission member through the transmission, so that when the second transmission member drives the driving rod to rotate, the anti-overload connecting member is in a transmission state; when the knob drives the spring to rotate and drives the first transmission member to rotate, when the first transmission member is subjected to the transmission resistance of the transmission cooperation with the second transmission member, the first transmission member compresses the spring, and the first transmission member rotates relative to the second transmission member, so that the driving rod stops rotating, and the anti-overload connecting member is in a relative rotation state.

[0009] Furthermore, the first transmission member is a first toothed disc, and the second transmission member is a second toothed disc; when the first toothed disc is meshed with the second toothed disc, the anti-overload connection assembly is in a transmission state; when the first toothed disc rotates relative to the second toothed disc, the anti-overload connection assembly is in a relative rotation state.

[0010] Furthermore, the intervertebral distraction tool also includes a torque adjuster movably arranged on the shell and a telescopic rod arranged between the second gear plate and the driving rod. The torque adjuster is connected to the spring, and the torque adjuster moves to compress and adjust the length of the spring to adjust the size of the elastic force of the spring.

[0011] Furthermore, the torque adjusting member includes an adjusting ring arranged on the outer side of the housing and a connecting piece extending into the housing, the first toothed disc is rotatably arranged on the connecting piece, and the adjusting ring moves to adjust the length of the spring through the first toothed disc.

[0012] Furthermore, a display window is provided on the shell, the display window is opened at the connecting piece and passes through the side wall of the shell, and a torque scale value corresponding to the connecting piece is provided at the display window of the shell.

[0013] Furthermore, a convex ring is provided on the second end of the driving rod, and the convex ring is located outside the sleeve. The intervertebral distraction tool also includes a limiting ring movably provided on the second end of the sleeve, and the limiting ring moves to have a limiting position in which the convex ring abuts against the limiting ring and the sleeve, and an avoidance position in which the convex ring can rotate relative to the limiting ring and the sleeve.

[0014] Furthermore, a polygonal rod segment is provided on the second end of the driving rod, and a polygonal hole capable of being plugged and matched with the polygonal rod segment is provided in the anti-overload connecting piece, and the polygonal rod segment is inserted into the polygonal hole so that the anti-overload connecting piece can cooperate with the driving rod to prevent rotation; and / or, the second end of the driving rod can be inserted into the anti-overload connecting piece, and an annular groove arranged around the driving rod is provided on the second end of the driving rod, and a limiting bead which is floatably arranged along the radial direction of the driving rod is provided in the anti-overload connecting piece, and when the second end of the driving rod is inserted into the anti-overload connecting piece, the limiting bead extends into the annular groove.

[0015] Furthermore, a threaded hole is provided on the abutment member, and a threaded section capable of cooperating with the threaded hole is provided on the first end of the driving rod. The driving rod rotates one circle so that the upper end plate and the lower end plate move away from or approach each other by a preset distance; a counter is provided on the outer shell, and the counter can record the number of rotations of the driving rod to calculate the distance value by which the upper end plate and the lower end plate move away from or approach each other.

[0016] According to the technical solution of the present invention, the intervertebral distraction tool includes: an upper end plate, a lower end plate, abutment, a sleeve, a driving rod and an anti-overload connection assembly. The lower end plate is arranged opposite to the upper end plate and is located below the upper end plate. The abutment abuts between the first end of the upper end plate and the first end of the lower end plate. The first end of the sleeve abuts between the second end of the upper end plate and the second end of the lower end plate. The driving rod passes through the sleeve and is rotatably arranged. The first end of the driving rod is connected to the abutment, and the driving rod rotates and drives the abutment to approach or move away from the sleeve along the axial direction of the sleeve. The abutment and the first end of the sleeve jointly push the upper end plate and the lower end plate so that the upper end plate and the lower end plate move away from or approach each other. In this way, when the driving rod rotates, the abutment can be moved closer to or away from the sleeve, so that the abutment and the sleeve can push the upper end plate and the lower end plate away from or lower the upper end plate, so that the distance between the upper end plate and the lower end plate can be increased or decreased to adjust the distance of the intervertebral distraction. The anti-overload connection assembly is connected to the second end of the driving rod and is located outside the sleeve, driving the anti-overload connection assembly to rotate to drive the driving rod to rotate. Wherein, the anti-overload connection assembly has a transmission state and a relative rotation state in sequence when rotating. When the anti-overload connection assembly is in the transmission state, the anti-overload connection assembly drives the driving rod to rotate so that the distance between the upper end plate and the lower end plate can be adjusted. When the anti-overload connection assembly is in the relative rotation state, the anti-overload connection assembly rotates relative to the driving rod, and the driving rod stops rotating so that the distance between the upper end plate and the lower end plate remains unchanged. In this way, the operator can drive the driving rod to rotate through the anti-overload connection piece to adjust the distance between the upper end plate and the lower end plate. In addition, the setting of the anti-overload connection piece enables the operator to directly drive the driving rod, so that when the operator applies a large force to drive the driving rod to rotate, the anti-overload connection piece can produce relative rotation with the driving rod, that is, when the operator applies a large force, the large force cannot drive the driving rod to rotate, thereby avoiding the upper end plate and the lower end plate from continuing to move away, and avoiding the problem of applying a large force to the intervertebral distraction to damage the vertebral autologous bone. By setting the anti-overload connector, the transmission can be disconnected when the force applied by the operator is large, avoiding the problem that the operator does not open the gap enough to avoid excessive opening force, and simplifying the convenience of intervertebral distraction operation. Therefore, the technical solution of the present application effectively solves the problem in the related art that the intervertebral distraction force is easily too large or too small, making the intervertebral distraction operation more troublesome. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic diagram of the exploded structure of an embodiment of an intervertebral distraction tool according to the present invention is shown;

[0019] Figure 2 Shows Figure 1 A front view schematic diagram of an intervertebral distraction tool;

[0020] Figure 3 Shows Figure 1 A perspective schematic diagram of an anti-overload connection assembly of an intervertebral distraction tool without showing an adjustment ring and a connecting piece;

[0021] Figure 4 Shows Figure 1 A perspective schematic diagram of an anti-overload connection assembly of an intervertebral distraction tool;

[0022] Figure 5 Shows Figure 1 A schematic diagram of a connection of an anti-overload connector of an intervertebral distraction tool;

[0023] Figure 6 Shows Figure 1 A curve diagram showing the corresponding relationship between the distraction force and the torque of the intervertebral distraction tool;

[0024] Figure 7 Shows Figure 1 Figure 2 shows the relationship between the distraction force and torque of the intervertebral distraction tool excluding the initial and final parts.

[0025] The above drawings include the following reference numerals:

[0026] 10. Upper end plate;

[0027] 20, lower end plate;

[0028] 30. Abutment;

[0029] 40. Sleeve;

[0030] 51. driving rod; 52. convex ring; 53. polygonal rod segment;

[0031] 61. housing; 611. display window; 612. torque scale value; 62. overload protection connector; 621. spring; 622. first toothed disc; 623. second toothed disc; 624. stopper bead; 625. polygonal hole; 63. knob; 64. counter;

[0032] 70. Telescopic rod;

[0033] 80. Limiting ring;

[0034] 91. Adjusting ring; 92. Connecting piece. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0038] In this embodiment, if Figures 1 to 5As shown, the intervertebral distraction tool includes: an upper end plate 10, a lower end plate 20, an abutment 30, a sleeve 40, a driving rod 51 and an anti-overload connection assembly. The lower end plate 20 is arranged opposite to the upper end plate 10 and is located below the upper end plate 10. The abutment 30 abuts between the first end of the upper end plate 10 and the first end of the lower end plate 20. The first end of the sleeve 40 abuts between the second end of the upper end plate 10 and the second end of the lower end plate 20. The driving rod 51 passes through the sleeve 40, and the driving rod 51 is rotatably arranged. The first end of the driving rod 51 is connected to the abutment 30, and the driving rod 51 rotates and drives the abutment 30 to approach or move away from the sleeve 40 along the axial direction of the sleeve 40. The first ends of the abutment 30 and the sleeve 40 jointly push the upper end plate 10 and the lower end plate 20 so that the upper end plate 10 and the lower end plate 20 move away from or approach each other. The anti-overload connection assembly is connected to the second end of the drive rod 51 and is located outside the sleeve 40, driving the anti-overload connection assembly to rotate to drive the drive rod 51 to rotate. Among them, the anti-overload connection assembly has a transmission state and a relative rotation state in sequence when rotating. When the anti-overload connection assembly is in the transmission state, the anti-overload connection assembly drives the drive rod 51 to rotate so that the distance between the upper end plate 10 and the lower end plate 20 can be adjusted. When the anti-overload connection assembly is in the relative rotation state, the anti-overload connection assembly rotates relative to the drive rod 51, and the drive rod 51 stops rotating so that the distance between the upper end plate 10 and the lower end plate 20 remains unchanged.

[0039] In this way, when the driving rod 51 rotates, the abutment 30 can be moved closer to or away from the sleeve 40, so that the abutment 30 and the sleeve 40 can push the upper end plate 10 and the lower end plate 20 away from or lower the upper end plate 10, so that the distance between the upper end plate 10 and the lower end plate 20 can be increased or decreased to adjust the distance of the intervertebral distraction. The anti-overload connection assembly is connected to the second end of the driving rod 51 and is located on the outside of the sleeve 40, driving the anti-overload connection assembly to rotate to drive the driving rod 51 to rotate. Among them, the anti-overload connection assembly has a transmission state and a relative rotation state in sequence when rotating. When the anti-overload connection assembly is in the transmission state, the anti-overload connection assembly drives the driving rod 51 to rotate so that the distance between the upper end plate 10 and the lower end plate 20 can be adjusted. When the anti-overload connection assembly is in the relative rotation state, the anti-overload connection assembly rotates relative to the driving rod 51, and the driving rod 51 stops rotating so that the distance between the upper end plate 10 and the lower end plate 20 remains unchanged. In this way, the operator can drive the driving rod 51 to rotate through the anti-overload connector 62 to adjust the distance between the upper end plate 10 and the lower end plate 20. In addition, the setting of the anti-overload connector 62 enables the operator to directly drive the driving rod 51, so that when the operator applies a large force to drive the driving rod 51 to rotate, the anti-overload connector 62 can rotate relative to the driving rod 51, that is, when the operator applies a large force, the large force cannot drive the driving rod 51 to rotate, thereby avoiding the upper end plate 10 and the lower end plate 20 from continuing to move away from each other, and avoiding the problem of applying a large force to the intervertebral distraction to damage the vertebral autologous bone. Through the setting of the anti-overload connector 62, the transmission can be disconnected when the force applied by the operator is large, avoiding the problem that the operator avoids the problem of insufficient distraction gap in order to avoid excessive distraction force, and simplifying the simplicity of intervertebral distraction operation. Therefore, the technical solution of the present application effectively solves the problem that the intervertebral distraction force in the related art is easy to be too large or too small, making the operation of intervertebral distraction more troublesome.

[0040] like Figures 1 to 5As shown, the anti-overload connection assembly includes a housing 61, an anti-overload connection member 62 disposed in the housing 61, and a knob 63 rotatably disposed on the housing 61, and the anti-overload connection member 62 is connected between the knob 63 and the drive rod 51. The housing 61 is provided for easy processing and for the provision of the anti-overload connection member 62. The provision of the knob 63 is convenient for the operation of the operator, and the operator drives the knob 63 to rotate so as to drive the drive rod 51 to rotate through the anti-overload connection member 62. When the knob 63 drives the anti-overload connection member 62 to rotate to drive the drive rod 51 to rotate, the anti-overload connection assembly is in a transmission state, so that the upper end plate 10 and the lower end plate 20 can approach or move away from each other, thereby adjusting the distance of the intervertebral distraction. When the knob 63 drives the anti-overload connection member 62 to rotate relative to the drive rod 51, the drive rod 51 stops rotating, and the anti-overload connection assembly is in a relative rotation state. In this way, when the operator applies a large screwing force to the knob 63, the anti-overload connector 62 can rotate relative to the drive rod 51, so that the drive rod 51 stops rotating, preventing the upper end plate 10 and the lower end plate 20 from continuing to move away from each other, preventing the vertebral space from continuing to expand, and thus reducing the possibility of damaging the vertebral autologous bone due to the large expansion force.

[0041] like Figures 1 to 5 As shown, the anti-overload connection member 62 includes a spring 621 fixedly connected to the knob 63, a first transmission member fixedly connected to the spring 621, and a second transmission member fixedly connected to the drive rod 51. The structure of the anti-overload connection member 62 is simple and compact, and is easy to process. The knob 63 drives the spring 621 to rotate, and the first transmission member cooperates with the second transmission member through the first transmission member, so that when the second transmission member drives the drive rod 51 to rotate, the anti-overload connection assembly is in a transmission state. In the process of the knob 63 driving the spring 621 to rotate and driving the first transmission member to rotate, when the first transmission member is subjected to the transmission resistance of the transmission cooperation with the second transmission member, the first transmission member compresses the spring 621, and the first transmission member rotates relative to the second transmission member, so that the drive rod 51 stops rotating, and the anti-overload connection assembly is in a relative rotation state. In this way, when the torque applied by the operator to the knob 63 is less than the preset spreading force value, the length of the spring 621 is greater than or equal to the preset length of the spring 621, the second transmission member can cooperate with the first transmission member, and the rotation of one end of the spring 621 can make the other end of the spring 621 drive the second transmission member to rotate, thereby driving the drive rod 51 to rotate, so that the upper end plate 10 and the lower end plate 20 can approach each other or move away from each other. When the torque applied by the operator to the knob 63 is greater than or equal to the preset spreading force value, the spring 621 receives a larger torque and is compressed, so that the length of the spring 621 is less than the preset length of the spring 621, and the second transmission is disconnected from the transmission of the first transmission member, thereby failing to drive the drive rod 51 to continue rotating, so that the upper end plate 10 and the lower end plate 20 can stop approaching each other or moving away from each other.

[0042] like Figures 1 to 5 As shown, the first transmission member is the first toothed disc 622, and the second transmission member is the second toothed disc 623. When the first toothed disc 622 is meshed with the second toothed disc 623, the anti-overload connection assembly is in a transmission state. When the first toothed disc 622 rotates relative to the second toothed disc 623, the anti-overload connection assembly is in a relative rotation state. The first toothed disc 622 and the second toothed disc 623 have a simple structure and are easy to process. When the torque applied by the operator to the knob 63 is greater than or equal to the preset opening force value, the spring 621 receives a larger torque and is compressed, so that the length of the spring 621 is less than the preset length of the spring 621, thereby causing the first toothed disc 622 and the second toothed disc 623 to slip relative to each other, and the transmission between the first toothed disc 622 and the second toothed disc 623 is disconnected, so that the drive rod 51 cannot continue to rotate.

[0043] like Figures 1 to 5 As shown, the intervertebral distraction tool also includes a torque adjustment member movably arranged on the housing 61 and a telescopic rod 70 arranged between the second toothed disc 623 and the driving rod 51. The torque adjustment member is connected to the spring 621, and the torque adjustment member moves to compress and adjust the length of the spring 621 to adjust the size of the elastic force of the spring 621. The size of the elastic force of the spring 621 can be adjusted by setting the torque adjustment member, thereby adjusting the maximum torque that can be transmitted by the anti-overload connection assembly, thereby adjusting the maximum distraction force that can be applied by the intervertebral distraction tool, and improving the adaptability of the intervertebral distraction tool. After the torque adjustment member compresses and shortens the spring 621, the pitch of the adjustment spring 621 is reduced, so that the spring 621 is not easy to be further compressed, thereby increasing the torque that can be transmitted by the spring 621, so that the operator can adjust the maximum support force according to the vertebral conditions of different patients. In addition, after the length of the spring 621 is adjusted, the first toothed disc 622 and the second toothed disc 623 can be engaged by adjusting the length of the telescopic rod 70.

[0044] like Figures 1 to 5 As shown, the torque adjustment member includes an adjustment ring 91 disposed on the outer side of the housing 61 and a connecting piece 92 extending into the housing 61. The first toothed disc 622 is rotatably disposed on the connecting piece 92, and the adjustment ring 91 moves to adjust the length of the spring 621 through the first toothed disc 622. This makes it more convenient for the adjustment ring 91 to adjust the length of the spring 621, and makes the rotation of the first toothed disc 622 smoother. In this embodiment, a bearing outer ring is disposed on the connecting piece 92, and a bearing inner ring is disposed on the first toothed disc 622, and the bearing inner ring is rotatably disposed in the bearing outer ring. In this embodiment, a spread height scale value is also disposed on the housing 61, and the spread height scale value ranges from 0 mm to 7 mm, and the spread height scale value is arranged around the circumference of the knob 63.

[0045] like Figures 1 to 5As shown, a display window 611 is provided on the housing 61, and the display window 611 is opened at the connecting piece 92 and penetrates the side wall of the housing 61. A torque scale value 612 corresponding to the connecting piece 92 is provided at the display window 611 of the housing 61. In this way, the display window 611 and the torque scale value 612 are provided so that the operator can know the maximum distraction force of the intervertebral distraction tool at this time according to the position of the adjusting connecting piece 92, and further simplify the operation of the intervertebral distraction.

[0046] In this embodiment, the torque that can be transmitted by the position of the connecting piece 92 and the corresponding length of the spring 621 is obtained according to calibration. The connecting piece 92 can be moved on the housing 61, and can be fixed on the housing 61, so that the length of the spring 621 can be adjusted or fixed. A fastener is provided on the adjusting ring 91, and when the fastener abuts against the housing 61, the adjusting ring 91 is fixed on the housing 61, so that the length of the spring 621 can be fixed.

[0047] like Figures 1 to 5 As shown, a convex ring 52 is provided on the second end of the driving rod 51, and the convex ring 52 is located outside the sleeve 40. The intervertebral distraction tool also includes a limiting ring 80 movably arranged on the second end of the sleeve 40. The limiting ring 80 moves to have a limiting position in which the convex ring 52 abuts between the limiting ring 80 and the sleeve 40 and an avoidance position in which the convex ring 52 can rotate relative to the limiting ring 80 and the sleeve 40. The above-mentioned setting structure is simple and easy to process. Through the setting of the convex ring 52 and the limiting ring 80, the driving rod 51 can rotate relative to the sleeve 40, or the driving rod 51 can stop rotating, which is convenient for the operator to operate. In addition, the setting of the limiting ring 80 and the convex ring 52 can limit the displacement of the driving rod 51 along its axial direction.

[0048] like Figures 1 to 5 As shown, a polygonal rod section 53 is provided on the second end of the driving rod 51. A polygonal hole 625 capable of plugging and matching with the polygonal rod section 53 is provided on the anti-overload connector 62, and the polygonal rod section 53 is inserted into the polygonal hole 625 so that the anti-overload connector 62 can be matched with the driving rod 51 to prevent rotation. The structure of the polygonal rod section 53 and the polygonal hole 625 is simple and easy to process. When the anti-overload connector 62 is in the transmission state, the knob 63 can drive the driving rod 51 to rotate synchronously through the anti-overload connector 62. The second end of the driving rod 51 can be inserted into the anti-overload connector 62, and the second end of the driving rod 51 is provided with an annular groove wound around the driving rod 51. A limiting bead 624 is provided in the anti-overload connector 62 so as to be floatable along the radial direction of the driving rod 51. When the second end of the driving rod 51 is inserted into the anti-overload connector 62, the limiting bead 624 extends into the annular groove. The structure of the annular groove and the limiting bead 624 is simple and easy to process, and is convenient for connecting the driving rod 51 with the anti-overload connecting piece 62 .

[0049] In this embodiment, the polygonal rod section 53 is connected to one end of the driving rod 51. The polygonal hole 625 is provided on one end of the telescopic rod 70 facing the driving rod 51. The two side walls of the annular groove along the axial direction of the driving rod 51 are provided with guiding inclined surfaces. When the operator applies a force along the axial direction of the driving rod 51, the limiting bead 624 can abut against the guiding inclined surfaces, so that the limiting bead 624 can be disengaged from the annular groove, so that the driving rod 51 can be separated from the overload protection connector 62.

[0050] In other embodiments, a polygonal rod segment 53 is provided on the second end of the driving rod 51. A polygonal hole 625 capable of plugging and matching with the polygonal rod segment 53 is provided on the anti-overload connector 62, and the polygonal rod segment 53 is inserted into the polygonal hole 625, so that the housing 61 can be anti-rotatingly matched with the driving rod 51. Alternatively, the second end of the driving rod 51 can be inserted into the housing 61, and an annular groove wound around the driving rod 51 is provided on the second end of the driving rod 51, and a limiting bead 624 is provided in the housing 61 so as to float along the radial direction of the driving rod 51, and when the second end of the driving rod 51 is inserted into the housing 61, the limiting bead 624 extends into the annular groove.

[0051] like Figures 1 to 5 As shown, a threaded hole is provided on the abutment 30, and a threaded section capable of cooperating with the threaded hole is provided on the first end of the driving rod 51. The structure of the threaded hole and the threaded rod is simple and easy to process, so that the driving rod 51 is more convenient to drive the abutment 30, and the rotation of the driving rod 51 can be effectively converted into the movement of the abutment 30. The driving rod 51 rotates one circle to make the upper end plate 10 and the lower end plate 20 move away from or approach each other by a preset distance. A counter 64 is provided on the housing 61, and the counter 64 can record the number of rotations of the driving rod 51 to calculate the distance value of the upper end plate 10 and the lower end plate 20 moving away from or approaching each other. In this way, the operator can know the distance between the upper end plate 10 and the lower end plate 20 at this time according to the number of rotations of the driving rod 51 and the value of the counter 64. In this embodiment, after the operator rotates the driving rod 51, the counter 64 is screwed to record the distance between the upper end plate 10 and the lower end plate 20 at this time.

[0052] In this embodiment, the operator determines the maximum distraction force of the intervertebral distraction tool according to the patient's vertebral bone density, and thereby converts the maximum distraction torque.

[0053] The inventors found that the related art uses a method of first driving pedicle screws into the pedicles of two adjacent vertebrae, and then expanding the intervertebral space by applying force to the screw tail of the pedicle screw, which has a complex structure and a large volume. In actual operation, this method is likely to cause the intervertebral space to form a wedge shape that is narrow in front and wide in the back, and due to the obstruction of the instrument itself, it is not conducive to observation and subsequent related operations, and it is very inconvenient to implement. Lumbar spondylolisthesis most often occurs in the middle-aged and elderly population. The bone quality of patients in this age group is generally poor. When the force of the opening is large, it is easy for the screw-bone interface to loosen, affecting the holding force of the pedicle screw, and sometimes causing the screw to loosen, directly affecting the operation. In addition, there is no fusion device with intervertebral space distraction force measurement, so it is impossible to accurately judge the size of the intervertebral space distracted by the distraction fusion device and the size of the distraction force during surgery. Moreover, each operator has different torque and operating habits, which may cause the intervertebral space to be too large or too small, insufficient or excessive distraction by the distraction device, and lead to the selection of the wrong size of intervertebral fusion device, which may lead to failure of intervertebral fusion or endplate rupture, resulting in complications such as a large increase in bleeding and settlement of the fusion device.

[0054] In order to overcome the deficiencies of the above prior art, the inventor provides an intervertebral distraction tool with a measurable distraction force and a distraction height through an additive manufacturing process and a minimally invasive channel. The minimally invasive intervertebral distraction tool with measurable distraction force can realize the adjustable structure and mechanism of the intervertebral distraction tool by distracting the movable abutment 30 through the upper end plate 10 and the lower end plate 20, and the tail cooperates with the sleeve 40 and the limit ring 80. The width of the intervertebral distraction tool in this application is 8mm and the minimum height is 7mm, which can effectively reduce the obstruction of the intervertebral distraction tool itself, reduce the impact on the observation of the operation and the obstruction of subsequent related operations. In the middle-aged and elderly people with lumbar spondylolisthesis, when encountering poor bone quality, the distraction position can be effectively selected to avoid damage to the bone, and at the same time avoid the loosening of the screw fixation caused by the distraction of the posterior screw. And the intervertebral distraction tool has a scale ruler for the distraction distance, which can intuitively understand whether the final distraction height is consistent with the expected result before the operation.

[0055] In this embodiment, the abutment member 30 includes a push block and a connecting shaft connected to the push block, and the connecting shaft is sandwiched between the upper end plate 10 and the lower end plate 20. The push block abuts between the first end of the upper end plate 10 and the first end of the lower end plate 20. The sleeve 40 abuts between the second end of the upper end plate 10 and the second end of the lower end plate 20. The push block and the connecting shaft have simple structures and are easy to process. A guide protrusion is provided on the connecting shaft, and a guide slideway that can cooperate with the guide protrusion is provided on the upper end plate 10. The setting of the guide protrusion and the guide slideway can guide the movement of the upper end plate 10 so that the upper end plate 10 can move smoothly along a preset direction. The guide slideway runs through the upper and lower surfaces of the upper end plate 10. When the distance between the upper end plate 10 and the lower end plate 20 is the smallest, one end of the guide protrusion protrudes or is flush with the upper surface of the upper end plate 10. In this way, the minimum height of the intervertebral distraction tool can be effectively reduced, making the structure of the intervertebral distraction tool more compact. Lowering the initial height of the intervertebral distraction tool can facilitate the operation of placing the intervertebral distraction tool into the intervertebral space, reduce damage to the autologous bone, and further simplify the use and operation of the intervertebral distraction tool. The upper end plate 10 and the lower end plate 20 can be better buckled. The angle between the extension direction of the slide groove and the center line of the connecting shaft is 50°, which can achieve a small axial stroke to achieve a large radial height adjustment, an axial stroke of 3mm, and a height of 7mm. The height adjustment range between the upper end plate 10 and the lower end plate 20 is 7mm to 14mm, and a self-locking and self-stabilizing structural form can be achieved. A torque sensor is connected at the tail to realize real-time display and control of torque, and the torque forms a linear equation relationship with the distraction force through the distraction screw thread structure, realizing real-time monitoring and release of torque and distraction force. There are four guide protrusions, and the four guide protrusions adopt an upper and lower mirror layout, and the front and rear guide protrusions are in a two-way array layout.

[0056] In this embodiment, Figure 6 A corresponding relationship curve diagram of the distraction force and torque of the intervertebral distraction tool is shown. The corresponding relationship curve diagram obtains data through actual mechanical testing, and the obtained data is marked in the figure. Figure 6 The horizontal axis represents the torque, and the unit of the torque is N*m. Figure 6 The vertical axis represents the expansion force, and the unit of the expansion force is N. Figure 7 The relationship between the distraction force and torque of the initial and final parts of the intervertebral distraction tool is shown. Figure 7 The corresponding relationship curve of the opening force and torque is not included in the initial part of the opening, and the corresponding relationship curve is obtained through actual mechanical testing, and the obtained data is marked in the figure. Figure 7 The corresponding relationship between the opening force and the torque in can derive the corresponding linear relationship equation between the opening force and the torque.

[0057] In this embodiment, the surface of the upper end plate 10 and the surface of the lower end plate 20 both have an arc-shaped anatomical structure, which is used to directly contact and expand the end plates of the upper and lower vertebrae to achieve good adhesion and support. The surface expansion layer of the upper end plate 10 and the lower end plate 20 both adopts a smooth arc-shaped structure design to prevent damage to the nerves and spinal cord during placement and removal.

[0058] In this embodiment, a pusher is provided on the first end of the sleeve 40, and the pusher abuts between the second end of the upper end plate 10 and the second end of the lower end plate 20. A first slide groove is provided on the pusher, and a first slider located in the first slide groove is provided on the upper end plate 10. When the upper end plate 10 and the lower end plate 20 move away from or approach each other, the first slider slides and cooperates with the first slide groove. The opening of the first slide groove is arranged toward the upper end plate 10, and the pusher is also provided with a first anti-slip protrusion located on the groove side wall of the first slide groove. A first anti-slip groove is provided on the first slider, and the first anti-slip protrusion is movably arranged in the first anti-slip groove and cooperates with the first anti-slip groove to prevent slipping. A second slide groove is provided on the abutting member 30, and a second slider located in the second slide groove is provided on the upper end plate 10. When the upper end plate 10 and the lower end plate 20 move away from or approach each other, the second slider slides and cooperates with the second slide groove. The opening of the second slide groove is arranged toward the upper end plate 10, and the abutment member 30 is also provided with a second anti-slip protrusion located on the groove side wall of the second slide groove. The second slider is provided with a second anti-slip groove, and the second anti-slip protrusion is movably arranged in the second anti-slip groove and anti-slippingly cooperates with the second anti-slip groove. The angle between the first anti-slip groove and the second anti-slip groove and the center line of the connecting shaft is 50°.

[0059] In this embodiment, the processing method of the intervertebral distraction tool is: using laser or high-energy electron beam rapid prototyping technology, high-temperature sintering, chemical corrosion, electrochemical deposition and other technologies, and other processing methods include precision casting, welding, mechanical cutting, discharge machining and the like; the hydroxyapatite coating is obtained by high-temperature spraying or electrochemical deposition. The intervertebral distraction tool is made of medical metal, which includes but is not limited to titanium and titanium alloys, cobalt alloys, medical stainless steel and other materials.

[0060] In this embodiment, the upper surface of the upper end plate 10 is an arcuate surface, and the arcuate surface has a highest point and a center point, and the highest point is located between the center point and the first end of the upper end plate 10. The second end of the sleeve 40 is provided with a first gripping protrusion, and the second end of the adjustment rod extends out of the sleeve 40, and the second end of the adjustment rod is provided with a second gripping protrusion. This allows the intervertebral distraction tool to be adapted to the vertebral autologous bone, achieving a better bone fit state and matching the curvature and angle of the vertebral bone end plate.

[0061] In this embodiment, the abutment member 30 includes a push block and a connecting shaft connected to the push block, and the connecting shaft is clamped between the upper end plate 10 and the lower end plate 20. The push block abuts between the first end of the upper end plate 10 and the first end of the lower end plate 20, and the sleeve 40 abuts between the second end of the upper end plate 10 and the second end of the lower end plate 20. The push block and the connecting shaft have simple structures and are easy to process. The end of the push block away from the sleeve 40 is provided with a first inclined surface, a second inclined surface, and a transition surface connecting the first inclined surface and the second inclined surface. The first inclined surface and the second inclined surface are arranged at an angle, and the distance between the first inclined surface and the second inclined surface gradually decreases in the direction from approaching the sleeve 40 to away from the sleeve 40. The arrangement of the first inclined surface and the second inclined surface facilitates the operation of placing the intervertebral prosthesis into the intervertebral space, reduces the diameter of the outer end of the push block, and enables the push block to enter the intervertebral space more conveniently, which is convenient for operation. The setting of the transition surface can connect the first inclined surface and the second inclined surface, reducing the damage to the autologous bone at the connection between the first inclined surface and the second inclined surface. The angle formed between the first inclined surface and the second inclined surface is greater than or equal to 100° and less than or equal to 120°, so as to further reduce the damage to the autologous bone at the connection between the first inclined surface and the second inclined surface. The transition surface includes a plane segment and a first curved surface segment and a second curved surface segment respectively connected to the two opposite ends of the plane segment, the first curved surface segment is connected to the first inclined surface, and the second curved surface segment is connected to the second inclined surface. The setting of the plane segment reduces the possibility that the transition surface protrudes from the side of the vertebral body, and the setting of the plane segment further reduces the damage to the autologous bone in the intervertebral space. The setting of the first curved surface segment and the second curved surface segment can better connect the plane segment with the first inclined surface and the second inclined surface, reduce the edges and angles on the surface of the push block, and further reduce the damage to the autologous bone in the intervertebral space.

[0062] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0063] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0064] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intervertebral distraction tool, characterized in that: include: upper endplate (10); A lower end plate (20) arranged opposite to the upper end plate (10) and located below the upper end plate (10); an abutment member (30) abutting between a first end of the upper end plate (10) and a first end of the lower end plate (20); a sleeve (40), wherein a first end of the sleeve (40) abuts between a second end of the upper end plate (10) and a second end of the lower end plate (20); a driving rod (51) passing through the sleeve (40) and being rotatably arranged, wherein a first end of the driving rod (51) is connected to the abutment member (30), wherein the driving rod (51) rotates and drives the abutment member (30) to move closer to or farther away from the sleeve (40) along the axial direction of the sleeve (40), and the abutment member (30) and the first end of the sleeve (40) jointly push the upper end plate (10) and the lower end plate (20) so that the upper end plate (10) and the lower end plate (20) move away from or closer to each other; an anti-overload connection assembly connected to the second end of the drive rod (51) and located outside the sleeve (40), driving the anti-overload connection assembly to rotate so as to drive the drive rod (51) to rotate; Wherein, when the anti-overload connection assembly rotates, it has a transmission state and a relative rotation state in sequence; when the anti-overload connection assembly is in the transmission state, the anti-overload connection assembly drives the drive rod (51) to rotate so that the distance between the upper end plate (10) and the lower end plate (20) can be adjusted; when the anti-overload connection assembly is in the relative rotation state, the anti-overload connection assembly rotates relative to the drive rod (51), and the drive rod (51) stops rotating so that the distance between the upper end plate (10) and the lower end plate (20) remains unchanged; The anti-overload connection assembly comprises a housing (61), an anti-overload connection member (62) disposed in the housing (61), and a knob (63) rotatably disposed on the housing (61), wherein the anti-overload connection member (62) is connected between the knob (63) and the driving rod (51); When the knob (63) drives the anti-overload connection member (62) to rotate so as to drive the drive rod (51) to rotate, the anti-overload connection assembly is in the transmission state; when the knob (63) drives the anti-overload connection member (62) and the drive rod (51) to rotate relative to each other, the drive rod (51) stops rotating and the anti-overload connection assembly is in the relative rotation state; The anti-overload connecting member (62) comprises a spring (621) fixedly connected to the knob (63), a first transmission member fixedly connected to the spring (621), and a second transmission member fixedly connected to the driving rod (51); The knob (63) drives the spring (621) to rotate, and the first transmission member cooperates with the second transmission member through transmission, so that when the second transmission member drives the drive rod (51) to rotate, the anti-overload connection assembly is in the transmission state; In the process where the knob (63) drives the spring (621) to rotate and drives the first transmission member to rotate, when the first transmission member is subjected to a transmission resistance of transmission cooperation with the second transmission member, the first transmission member compresses the spring (621), and the first transmission member rotates relative to the second transmission member, so that the drive rod (51) stops rotating, and the anti-overload connection component is in the relative rotation state; the first transmission member is a first toothed disc (622), and the second transmission member is a second toothed disc (623); when the first toothed disc (622) is meshed with the second toothed disc (623), the anti-overload connection component is in the transmission state; when the first toothed disc (622) rotates relative to the second toothed disc (623), the anti-overload connection component is in the relative rotation state.

2. The intervertebral distraction tool according to claim 1, characterized in that: The intervertebral distraction tool also includes a torque adjustment member movably arranged on the housing (61) and a telescopic rod (70) arranged between the second toothed disc (623) and the driving rod (51), wherein the torque adjustment member is connected to the spring (621), and the torque adjustment member moves to compress and adjust the length of the spring (621) to adjust the magnitude of the elastic force of the spring (621).

3. The intervertebral distraction tool according to claim 2, characterized in that: The torque adjustment member comprises an adjustment ring (91) arranged on the outside of the housing (61) and a connecting piece (92) extending into the housing (61); the first toothed disc (622) is rotatably arranged on the connecting piece (92); the adjustment ring (91) moves to adjust the length of the spring (621) through the first toothed disc (622).

4. The intervertebral distraction tool according to claim 3, characterized in that: A display window (611) is provided on the housing (61), the display window (611) is opened at the connecting piece (92) and penetrates the side wall of the housing (61), and a torque scale value (612) corresponding to the connecting piece (92) is provided at the display window (611) of the housing (61).

5. The intervertebral distraction tool according to claim 1, characterized in that: A convex ring (52) is arranged on the second end of the driving rod (51), and the convex ring (52) is located outside the sleeve (40). The intervertebral distraction tool also includes a limiting ring (80) movably arranged on the second end of the sleeve (40), and the limiting ring (80) moves to have a limiting position in which the convex ring (52) abuts between the limiting ring (80) and the sleeve (40) and an avoidance position in which the convex ring (52) can rotate relative to the limiting ring (80) and the sleeve (40).

6. The intervertebral distraction tool according to claim 1, characterized in that: A polygonal rod segment (53) is provided on the second end of the driving rod (51), a polygonal hole (625) capable of plugging and cooperating with the polygonal rod segment (53) is provided on the anti-overload connecting piece (62), and the polygonal rod segment (53) is inserted into the polygonal hole (625) so that the anti-overload connecting piece (62) can engage with the driving rod (51) in a rotation-stopping manner; and / or, The second end of the driving rod (51) can be inserted into the anti-overload connecting piece (62); an annular groove arranged around the driving rod (51) is provided on the second end of the driving rod (51); a limiting bead (624) is provided in the anti-overload connecting piece (62) and is arranged to float along the radial direction of the driving rod (51); when the second end of the driving rod (51) is inserted into the anti-overload connecting piece (62), the limiting bead (624) extends into the annular groove.

7. The intervertebral distraction tool according to claim 1, characterized in that: The abutment member (30) is provided with a threaded hole, and the first end of the driving rod (51) is provided with a threaded section capable of cooperating with the threaded hole, and the driving rod (51) rotates one circle so that the upper end plate (10) and the lower end plate (20) move away from each other or approach each other by a preset distance; A counter (64) is provided on the housing (61), and the counter (64) is capable of recording the number of rotations of the driving rod (51) to calculate the distance value by which the upper end plate (10) and the lower end plate (20) move away from or toward each other.

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