Pedicle screw and fixing system thereof

Abstract

The utility model relates to a pedicle screw and a fixing system thereof, the pedicle screw comprises a screw body, a screw seat and a gasket, the screw body comprises a screw rod and a screw head which are connected, the peripheral surface of the screw head is a spherical surface, a first external thread is arranged on the spherical surface, two ends of the screw seat are respectively provided with a U-shaped groove and a ball groove, and the gasket is arranged in the U-shaped groove. The U-shaped groove is used for installing a connecting rod, a first internal thread is arranged in the ball groove, a screwing-in opening is formed in the end, away from the U-shaped groove, of the ball groove, the nail head can be screwed into the ball groove through the screwing-in opening and is in threaded fit with the ball groove, the gasket is installed in the nail base, and the screw head is connected with the gasket. At least part of the gasket extends into the ball groove and abuts against the nail head. According to the pedicle screw, the problems of interference and view shielding of the screw base in the operation process can be solved, and the operation time is shortened.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical instrument technical field, specifically, a pedicle screw and its fixed system. BACKGROUND

[0002] The pedicle screw is the internal fixation device commonly used in the spine surgery. The pedicle screw can be divided into two structures of integral type and split type. For the integral type pedicle screw, the pedicle screw is mainly composed of a nail seat, a nail body and a screw plug. In assembling the pedicle screw, the nail body is first passed through the nail seat and connected into an integral body, the nail body can realize a certain rotation and swing in the nail cap, then the nail body is implanted into the vertebra, and is fixed by the screw plug. But in the surgical process, the nail seat of the pedicle screw will block the view of the doctor, it is inconvenient for the doctor to directly observe the affected area, and it will interfere with the CT perspective, resulting in the inconvenience of the doctor's operation and affecting the progress of the operation. SUMMARY

[0003] The utility model aims at at least in a certain extent solves one of the technical problems in the prior art.

[0004] Therefore, the embodiment of the utility model provides a kind of pedicle screw, which can avoid the interference of nail seat in the surgical process, block the view problem, shorten the operation time.

[0005] The embodiment of the utility model further provides a kind of pedicle screw fixing system.

[0006] The pedicle screw of the embodiment of the utility model includes: nail body, the nail body includes connected nail rod and nail head, the outer circumferential surface of the nail head is spherical surface, and first outer thread is arranged on the spherical surface;Nail seat, the two ends of the nail seat are respectively provided with U-shaped groove and ball groove, the U-shaped groove is used for installing connecting rod, first inner thread is arranged in the ball groove, the end of the ball groove away from the U-shaped groove is provided with spin entry, the nail head can be screwed into the ball groove by the spin entry, and is threadedly matched with the ball groove;Gasket, the gasket is installed in the nail seat, and at least part of the gasket extends into the ball groove and abuts against the nail head.

[0007] According to the pedicle screw of the embodiment of the utility model, when the pedicle screw is implanted, the nail body can be implanted into the vertebra first, and then the nail seat is screwed onto the nail body from the spin entry. Since the nail seat does not need to be installed before the nail body is implanted, the implantation of the pedicle screw can be more flexible, and the interference of the nail seat to the implantation of the nail body and the blocking of the view are avoided, so as to facilitate the operation of the doctor, and shorten the operation time. Since the nail head and the nail seat are the matching structure of spherical surface and ball groove, the nail body can have a certain swing angle relative to the nail seat, different implantation angles of the pedicle screw can be met, and the gasket can limit the nail head to improve the stability of the installation of the nail body and the nail seat.

[0008] In some embodiments, the pin seat is provided with a communication channel, two ends of the communication channel are communicated with the U-shaped groove and the ball groove respectively, the gasket is installed in the communication channel, one end of the gasket extends into the U-shaped groove and can abut against the connecting rod, and part of the inner wall of the U-shaped groove is formed by the gasket, the other end of the gasket extends into the ball groove.

[0009] In some embodiments, the inner wall of the communication channel is provided with a protruding structure, the outer wall of the gasket is provided with a groove, and the protruding structure is matched in the groove to limit the gasket from coming out of the pin seat.

[0010] In some embodiments, the groove is long strip-shaped and extends along the axial direction of the pin seat, and the protruding structure is slidingly matched with the groove along the axial direction of the pin seat; and / or, the pedicle screw further comprises an ejector, the outer wall of the pin seat is provided with a locking hole, the locking hole extends along the radial direction of the pin seat, the inner end of the locking hole is spaced apart from the inner wall of the communication channel to form a thin wall part, the ejector penetrates into the locking hole and extrudes the thin wall part, and the thin wall part is deformed to form the protruding structure.

[0011] In some embodiments, one end of the gasket has an arc-shaped support part, the arc-shaped support part extends into the U-shaped groove and can abut against the connecting rod, and the other end of the gasket has a ball-shaped groove, the ball-shaped groove abuts against the pin head.

[0012] In some embodiments, the width of the U-shaped groove is f1, the arc-shaped support part has an arc-shaped groove, and the width of the arc-shaped groove is f2, wherein 6.1mm≤f1≤6.5mm and 6.0mm≤f2≤6.4mm; and / or, the arc-shaped support part has an arc-shaped groove, and the bottom edges on both sides of the arc-shaped groove along the length direction of the connecting rod are provided with avoiding notches; and / or, the gasket is provided with a communication hole, the communication hole penetrates through the gasket along the axial direction of the pin seat; and / or, the arc-shaped support part has an arc-shaped groove, and the depth of the arc-shaped groove is greater than or equal to the radius of the connecting rod.

[0013] In some embodiments, the gasket comprises a cylindrical body and protruding parts symmetrically arranged on both sides of the body along the radial direction of the body, both the protruding parts are located below the arc-shaped groove, and the avoiding notches are arranged at the top ends of the protruding parts.

[0014] In some embodiments, the first external thread has a pitch p1, wherein 0.7mm≤p1≤1.5mm; and / or, the first external thread has a thread width m, wherein 0.2mm≤m≤0.8mm; and / or, a gap between the spherical surface and the spherical groove is a, wherein 0.02mm≤a≤0.2mm; and / or, a gap between a diameter of the spherical surface and a large diameter of the first internal thread is b, wherein 0.02mm≤b≤0.6mm; and / or, the first external thread is a single thread, a double thread or a multi-thread; and / or, a cross section of the first external thread is a triangle, a trapezoid or a rectangle; and / or, a transition round corner r is provided at a connecting position of the shank and the head, wherein 0.3mm≤r≤1.5mm; and / or, a distance between a center of the spherical surface and the rotation inlet is k, wherein 1.2mm≤k≤3.2mm; and / or, the head has a quincunx hole at an end away from the shank, and a bottom surface of the quincunx hole is a plane.

[0015] In some embodiments, the shank is provided with a second external thread, and the second external thread has a pitch p2, wherein 0.8mm≤p2≤3.5mm; and / or, the shank is provided with a second external thread, and the second external thread comprises a first segment, a second segment and a third segment, which are arranged in sequence from an end away from the head to an end adjacent to the head, and an outer diameter of the first segment and the third segment gradually increases, and an outer diameter of the second segment is constant; and / or, the shank has a shank tip at an end away from the head, and the shank tip is a pyramid structure; and / or, the shank is provided with a second external thread, and the second external thread is a single thread, a double thread or a single-double thread; and / or, the side wall of the seat is provided with two lifting grooves, and the two lifting grooves are symmetrically arranged on two sides of the seat; and / or, the pedicle screw further comprises a plug, an outer wall of the plug is provided with a third external thread, an inner wall of the U-shaped groove is provided with a third internal thread, a radially inner side of the third internal thread has a barb groove, the third external thread cooperates with the third internal thread and is locked with the barb groove; and / or, the seat is a short tail structure, a long tail structure or a minimally invasive structure.

[0016] According to another embodiment of the pedicle screw fixing system of the utility model, the connecting rod is inserted into the U-shaped groove, and the pedicle screw further comprises a plug, and the screw is screwed in the U-shaped groove and compresses the connecting rod.

[0017] According to the embodiment of the utility model, when the pedicle screw is implanted, the nail body can be implanted into the vertebra first, and then the nail seat is screwed on the nail body from the screw hole, the nail seat does not need to be installed before the nail body is implanted, so that the implantation of the pedicle screw is more flexible, and the interference and the shielding of the field of vision of the nail seat during the implantation of the nail body are avoided, so as to facilitate the operation of the doctor during the operation and shorten the operation time, the nail head and the nail seat are the matching structure of the spherical surface and the ball groove, so that the nail body can have a certain swing angle relative to the nail seat, different implantation angles of the pedicle screw can be met, and the gasket can limit the nail head, so that the stability of the installation of the nail body and the nail seat is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the schematic diagram of the pedicle screw of the utility model embodiment.

[0019] Figure 2 It is the longitudinal section view of the pedicle screw of the utility model embodiment.

[0020] Figure 3 It is the schematic diagram of the nail body of the pedicle screw of the utility model embodiment.

[0021] Figure 4 It is the partial section view of the nail body of the pedicle screw of the utility model embodiment.

[0022] Figure 5 It is the partial schematic diagram of the nail body of the pedicle screw of the utility model embodiment.

[0023] Figure 6 It is the schematic diagram of the nail seat of the pedicle screw of the utility model embodiment.

[0024] Figure 7 It is the longitudinal section view of the nail seat of the pedicle screw of the utility model embodiment.

[0025] Figure 8 It is the cross section view of the nail seat of the pedicle screw of the utility model embodiment.

[0026] Figure 9 It is the schematic diagram of the gasket of the pedicle screw of the utility model embodiment.

[0027] Figure 10 It is the longitudinal section view of the gasket of the pedicle screw of the utility model embodiment.

[0028] Figure 11 It is the schematic diagram of the nail seat of the pedicle screw of the utility model embodiment.

[0029] Figure 12 It is the schematic diagram of the nail seat of the pedicle screw of the utility model embodiment.

[0030] Figure label:

[0031] 1. Nail body; 11. Nail shank; 111. Second external thread; 12. Nail head; 121. Spherical surface; 122. First external thread; 123. Plexicon hole; 13. Nail tip; 14. Transition fillet;

[0032] 2. Pin seat; 21. U-shaped groove; 211. Third internal thread; 212. Barbed groove; 22. Ball groove; 221. First internal thread; 23. Thread inlet; 24. Connecting channel; 25. Locking hole; 26. Thin-walled section; 27. Lifting groove;

[0033] 3. Washer; 31. Groove; 32. Arc-shaped support; 321. Arc-shaped groove; 33. Spherical groove; 34. Clearance notch; 35. Connecting hole; 36. Body; 37. Protrusion. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0035] The following is a reference appendix. Figures 1 to 12 This invention describes an embodiment of a pedicle screw and its fixation system.

[0036] like Figures 1 to 7 As shown, the pedicle screw of this utility model embodiment includes: a screw body 1 and a screw seat 2. The screw body 1 includes a connected screw shank 11 and a screw head 12. The outer peripheral surface of the screw head 12 is a spherical surface 121, and a first external thread 122 is provided on the spherical surface 121. The two ends of the screw seat 2 are respectively provided with a U-shaped groove 21 and a ball groove 22. The U-shaped groove 21 is used to install a connecting rod (not shown). The ball groove 22 is provided with a first internal thread 221. The end of the ball groove 22 away from the U-shaped groove 21 is provided with a screw inlet 23. The screw head 12 can be screwed into the ball groove 22 through the screw inlet 23 and is threadedly engaged with the ball groove 22.

[0037] According to an embodiment of the present invention, during pedicle screw implantation, the screw body 1 can be implanted into the vertebral bone first, and then the screw seat 2 can be screwed onto the screw body 1 through the screw inlet 23. Since the screw seat 2 does not need to be installed before the screw body 1 is implanted, the implantation of the pedicle screw is more flexible, and the screw seat 2 avoids interference with or obstruction of the field of vision during the implantation of the screw body 1, facilitating the surgeon's intraoperative operation and shortening the operation time. Furthermore, since the screw head 12 and the screw seat 2 have a spherical surface 121 and a ball groove 22 mating structure, the screw body 1 can have a certain swing angle relative to the screw seat 2, which can meet different implantation angles of the pedicle screw, facilitating the installation of the connecting rod.

[0038] In another aspect, compared with the conventional integral pedicle screw, the pedicle screw of the utility model can reduce the inventory in the production process, and greatly improves the lean production and lean management of enterprises. Compared with the conventional assembled pedicle screw, the pedicle screw of the utility model can be repeatedly installed and removed without affecting the mechanical properties.

[0039] In the related art, before the pedicle screw is implanted into the vertebra, the shank 1 needs to be inserted into the seat 2 to connect the seat 2 and the shank 1 into a whole, but in the above scheme, the seat 2 will block the view of the doctor, which is not convenient for the doctor to directly observe the affected area, and will interfere with the CT perspective, causing the doctor to operate inconveniently in the operation and affecting the operation progress. The pedicle screw of the embodiment of the utility model can implant the shank 1 first, and then install the seat 2 on the shank 1, which can facilitate the doctor to operate in the operation, and allows the doctor to choose open surgery, minimally invasive surgery, Midline surgery and the like at any time according to the actual situation of the patient in the operation, so that the selection of the operation method is more flexible.

[0040] As shown in Figure 2 , Figure 7 and Figure 10 , the pedicle screw further comprises a washer 3 installed in the seat 2, and at least part of the washer 3 extends into the ball groove 22 and abuts against the head 12. It can be understood that when the head 12 is screwed into the ball groove 22 and reaches the set position, the washer 3 can abut against the head 12, thereby limiting the position of the head 12 and limiting the movement of the head 12 relative to the seat 2, so as to improve the stability of the installation of the shank 1 and the seat 2.

[0041] Specifically, as shown in Figure 2 and Figure 7 , the seat 2 is provided with a communication channel 24, the two ends of the communication channel 24 are respectively communicated with the U-shaped groove 21 and the ball groove 22, the washer 3 is installed in the communication channel 24, one end of the washer 3 extends into the U-shaped groove 21 and can abut against the connecting rod, the one end of the washer 3 constitutes part of the inner wall of the U-shaped groove 21, and the other end of the washer 3 extends into the ball groove 22. It can be understood that the communication channel 24 penetrates the seat 2 along the axial direction of the seat 2, one end of the communication channel 24 is communicated with the U-shaped groove 21, and the other end of the communication channel 24 is communicated with the ball groove 22.

[0042] Since one end of the washer 3 extends into the U-shaped groove 21 and constitutes part of the inner wall of the U-shaped groove 21, when the connecting rod is installed into the U-shaped groove 21, the connecting rod can abut against the washer 3, so that the washer 3 can positionally constrain the head 12 and the connecting rod, thereby improving the stability of the connection of the connecting rod, the seat 2 and the shank 1.

[0043] Optionally, asFigure 6 and Figure 7 As shown, the inner wall of the connecting channel 24 is provided with a protruding structure (not shown), and the outer wall of the washer 3 is provided with a groove 31. The protruding structure fits into the groove 31 to prevent the washer 3 from coming out of the nail seat 2. Under the cooperation of the protruding structure and the groove 31, the protruding structure can constrain the position of the washer 3 to avoid the problem of the washer 3 and the nail seat 2 becoming loose during the installation of the pedicle screw.

[0044] Understandably, after the washer 3 is placed into the staple seat 2, the protruding structure can protrude towards the groove 31 to pre-fix the washer 3, thereby avoiding the problem of the washer 3 detaching from the staple seat 2 during subsequent assembly, so as to facilitate the doctor's operation during the operation.

[0045] For example, the groove 31 is elongated and extends along the axial direction of the nail seat 2, and the protruding structure slides in conjunction with the groove 31 along the axial direction of the nail seat 2. It can be understood that, under the action of the protruding structure and the groove 31, the washer 3 can move slightly relative to the nail seat 2 along the axial direction of the nail seat 2 to accommodate connecting rods and nail bodies 1 of different specifications, thereby expanding the application range of pedicle screws.

[0046] In one example, such as Figure 6 and Figure 7 As shown, the pedicle screw also includes an ejector (not shown). The outer wall of the screw base 2 has a locking hole 25 extending radially along the screw base 2. The inner end of the locking hole 25 is spaced apart from the inner wall of the communicating channel 24 to form a thin-walled portion 26. The ejector is inserted into the locking hole 25 and presses against the thin-walled portion 26, causing the thin-walled portion 26 to deform and form a protruding structure. It can be understood that the ejector presses against the thin-walled portion 26 radially along the screw base 2 to cause a certain deformation in the thin-walled portion 26, i.e., the thin-walled portion 26 protrudes towards the groove 31 to form a bulge (protruding structure).

[0047] The pedicle screw of this utility model fixes the screw seat 2 and the washer 3 in the above manner. This not only clamps the washer 3 to ensure the firmness of the washer 3 installation, but also allows the washer 3 to move slightly relative to the screw seat 2 along the axial direction of the screw seat 2 to adapt to different specifications of connecting rods and screw bodies 1, resulting in better performance.

[0048] For example, such as Figure 7 As shown, the thickness of the thin-walled portion 26 is 0.1mm-0.3mm.

[0049] In another example, the locking hole 25 passes through the nail seat 2 and is opposite to the groove 31. The ejector is inserted through the locking hole 25 and extends into the groove 31, thereby the ejector can positionally constrain the washer 3. The end of the ejector can be spaced a certain distance from the groove wall of the groove 31 to allow the washer 3 to move slightly relative to the nail seat 2 along the axial direction of the nail seat 2.

[0050] In some embodiments, as shown in Figure 2 , Figure 7 and Figure 10 , one end of the washer 3 has an arc-shaped support portion 32 which extends into the U-shaped groove 21 and can abut against the connecting rod, and the other end of the washer 3 has a spherical groove 33 which abuts against the nail head 12. It can be understood that the wall surface of the arc-shaped support portion 32 and the wall surface of the U-shaped groove 21 are smoothly connected, so as to jointly support the connecting rod. The spherical groove 33 and the spherical surface 121 of the nail head 12 adopt a surface contact form, so that the installation firmness of the washer 3 and the nail head 12 can be improved.

[0051] For example, as shown in Figure 9 and Figure 10 , the arc-shaped support portion 32 has an arc-shaped groove 321, and in the projection plane perpendicular to the axial direction of the connecting rod, the outer periphery contour of the arc-shaped groove 321 is in the shape of a circular arc or a U shape. The arc-shaped groove 321 constitutes the bottom of the U-shaped groove 21, so that when the connecting rod is installed into the U-shaped groove 21, the arc-shaped groove 321 of the washer 3 can support and tightly abut against the connecting rod, so that the firmness of the connecting rod and the nail seat 2 can be improved.

[0052] Optionally, the depth of the arc-shaped groove 321 is greater than or equal to the radius of the connecting rod, so that the arc-shaped groove 321 can wrap the connecting rod, so as to further increase the contact area of the arc-shaped support portion 32 and the connecting rod, and improve the stability of the installation of the connecting rod. In other embodiments, the depth of the arc-shaped groove 321 can also be less than the radius of the connecting rod.

[0053] Optionally, the width (such as the size in the left-right direction of the U-shaped groove 21 in Figure 7 ) of the U-shaped groove 21 is f1, the arc-shaped support portion 32 has an arc-shaped groove 321, and the width of the arc-shaped groove 321 is f2, wherein 6.1mm≤f1≤6.5mm and 6.0mm≤f2≤6.4mm. It should be noted that f1 is slightly greater than f2. When the connecting rod is installed into the U-shaped groove 21, the bottom of the connecting rod cooperates with the arc-shaped groove 321 to clamp and fix the connecting rod. For example, f1 is 6.1mm, 6.2mm, 6.3mm, 6.4mm or 6.5mm. f2 is 6.0mm, 6.1mm, 6.2mm, 6.3mm or 6.4mm.

[0054] The pedicle screw of the embodiment of the utility model can accommodate the connecting rod with φ5.5mm, φ6.0, φ6.35 or other specifications by using the above parameter range of the U-shaped groove 21 and the arc-shaped groove 321, so as to expand the application range of the pedicle screw, and can meet the needs of different surgical procedures.

[0055] Optionally, as shown in Figure 9As shown, the bottom edges of the arc-shaped groove 321 along both sides of the connecting rod's length direction are provided with clearance notches 34. For example, the clearance notch 34 is a transition rounded corner with a radius between 0.2mm and 1.0mm. The clearance notch 34 can effectively reduce the impact damage of the washer 3 edge to the connecting rod during the contact between the washer 3 and the connecting rod, thereby improving the fatigue life of the connecting rod and enhancing the product's safety performance.

[0056] In one example, such as Figure 9 As shown, the washer 3 includes a cylindrical body 36 and protrusions 37 symmetrically arranged on both sides of the body 36 along its radial direction. Both protrusions 37 are located below the arc-shaped groove 321, and clearance notches 34 are provided at the top of the protrusions 37. It can be understood that the protrusions 37 are located on the outside of the body 36. The protrusions 37 can improve the overall structural strength of the washer 3, and can provide auxiliary support for the connecting rod. The clearance notches 34 allow for clearance, thereby improving the fatigue life of the connecting rod and enhancing the product's safety performance. Simultaneously, it ensures the anti-rotation effect between the washer 3 and the screw seat 2, and increases the contact area between the washer 3 and the connecting rod, thus improving the stability after the pedicle screw is finally locked and fixed.

[0057] Specifically, such as Figure 9 As shown, the washer 3 has a connecting hole 35, which extends through the washer 3 along the axial direction of the nail seat 2. It can be understood that the connecting hole 35 is used to pass a tool wrench through. After the nail seat 2 is installed to the nail head 12, the tool wrench can be passed through the connecting hole 35 so that the doctor can tighten the nail body 1 without removing the nail seat 2, thus saving surgical time.

[0058] For example, such as Figure 5 As shown, the end of the nail head 12 facing away from the nail shank 11 has a box-shaped hole 123, the bottom surface of which is flat. This means the wrench is a box-shaped wrench, which can pass through the connecting hole 35 and engage with the box-shaped hole 123 to tighten the nail body 1. Because the bottom surface of the box-shaped hole 123 is flat, the contact area between the box-shaped hole 123 and the counter-tool is increased, thereby enhancing the stability of holding the nail body 1.

[0059] In some embodiments, the pitch of the first external thread 122 is p1, wherein 0.7mm≤p1≤1.5mm. For example, the pitch p1 of the first external thread 122 is 0.7mm, 0.9mm, 1.1mm, 1.3mm, or 1.5mm.

[0060] The tooth width of the first external thread 122 is m, where 0.2mm ≤ m ≤ 0.8mm. For example, the tooth width m of the first external thread 122 is 0.2mm, 0.4mm, 0.6mm, or 0.8mm.

[0061] The inventor of the present application finds through experimental research that when the pitch p1 and the thread width m of the first external thread 122 adopt the above parameter ranges, the stability of the connection between the nail head 12 and the nail seat 2 can be improved, and the nail head 12 is not easy to loosen, and the use effect is better.

[0062] The first external thread 122 and the first internal thread 221 can be ordinary single thread, double thread or multi-thread, and the thread section of the first external thread 122 and the first internal thread 221 can be triangular, trapezoidal or rectangular.

[0063] Optionally, the gap a between the spherical surface 121 and the ball groove 22 is 0.02mm≤a≤0.2mm. For example, the gap a between the spherical surface 121 and the ball groove 22 is 0.02mm, 0.05mm, 0.1mm, 0.15mm or 0.2mm.

[0064] Further, the gap b between the diameter of the spherical surface 121 and the large diameter of the first internal thread 221 is 0.02mm≤b≤0.6mm. For example, the gap b between the diameter of the spherical surface 121 and the large diameter of the first internal thread 221 is 0.02mm, 0.2mm, 0.4mm, 0.5mm or 0.6mm.

[0065] The inventor of the present application finds through experimental research that when the gap a between the spherical surface 121 and the ball groove 22 and the gap b between the diameter of the spherical surface 121 and the large diameter of the first internal thread 221 adopt the above parameter ranges, on the one hand, the stability of the connection between the nail head 12 and the nail seat 2 can be improved, and the nail head 12 is not easy to loosen. On the other hand, the nail head 12 can be allowed to swing a certain angle relative to the nail seat 2 to adapt to different implantation angles of the pedicle screw.

[0066] Optionally, the transition round corner 14 at the connection position of the nail shaft 11 and the nail head 12 has a radius r of 0.3mm≤r≤1.5mm. For example, the transition round corner r at the connection position of the nail shaft 11 and the nail head 12 is 0.3mm, 0.5mm, 1.0mm or 1.5mm. The inventor of the present application finds through experimental research that when the transition round corner r adopts the above numerical range, the structural safety strength of the nail body 1, especially the fatigue strength of the nail body 1, can be greatly improved.

[0067] Optionally, the distance k between the center of the spherical surface 121 and the rotation inlet 23 is 1.2mm≤k≤3.2mm. For example, the distance k between the center of the spherical surface 121 and the rotation inlet 23 can be 1.2mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm or 3.2mm. The inventor of the present application finds through experimental research that when the distance k between the center of the spherical surface 121 and the rotation inlet 23 adopts the above numerical range, the swing angle size of the nail head 12 in the nail seat 2 can be ensured not to be affected, and the firmness of the connection between the nail head 12 and the nail seat 2 can be improved, and the risk of the nail head 12 coming out of the nail seat 2 can be reduced.

[0068] Optionally, as shown in Figure 2 The second external thread 111 is provided on the nail rod 11, and the pitch of the second external thread 111 is p2, where 0.8mm≤p2≤3.5mm. For example, the pitch p2 of the second external thread 111 can be 0.8mm, 1.5mm, 2.0mm, 3.0mm, or 3.5mm. The pedicle screw of the embodiment of the present application can improve the pull-out resistance of the nail rod 11 after implantation by designing the second external thread 111 to have the above parameters, thereby reducing the risk of loosening of the nail rod 11.

[0069] For example, the second external thread 111 can be a single-thread, a double-thread, or a single-double thread.

[0070] Specifically, as shown in Figure 1 and Figure 2 The second external thread 111 includes a first section, a second section, and a third section, which are arranged in sequence from the end away from the nail head 12 to the end adjacent to the nail head 12, and the outer diameter of the first section and the third section gradually increases, and the outer diameter of the second section is constant, thereby improving the pull-out resistance of the nail rod 11 after being driven into the vertebral body and ensuring the overall performance and safety strength of the pedicle screw.

[0071] Further, as shown in Figure 1 and Figure 2 The end of the nail rod 11 away from the nail head 12 has a nail tip 13, and the nail tip 13 has a pyramid structure. For example, the nail tip 13 has a three-sided taper (triple pyramid) structure. Compared with conventional pedicle screws, the pedicle screw of the present application can be implanted without pre-drilling, i.e., a drill bit structure is used to form a self-guiding function.

[0072] Optionally, as shown in Figure 9 and Figure 10 The side wall of the nail seat 2 is provided with two lifting grooves 27, and the two lifting grooves 27 are symmetrically arranged on both sides of the nail seat 2. Therefore, the doctor can use a tool to clamp the column lifting groove 27 to install and remove the nail seat 2, thereby facilitating the intraoperative operation of the doctor. The outer peripheral contour of the lifting groove 27 can be circular, elliptical, or strip-shaped.

[0073] In this embodiment, the nail seat 2 has a short tail structure, and in other embodiments, the nail seat 2 can also have a long tail structure or a minimally invasive structure.

[0074] In the examples of the present application, the pedicle screw further comprises a screw plug (not shown), the outer wall of the screw plug is provided with a third external thread, the inner wall of the U-shaped groove 21 is provided with a third internal thread 211, the radially inner side of the third internal thread 211 has a barb groove 212 (for example, a right-angled barb groove 212), the third external thread cooperates with the third internal thread 211 and is locked with the barb groove 212. When the screw plug is screwed to the third internal thread 211, due to the structure that the radially inner side of the third internal thread 211 has the barb groove 212, in the final locked state, the screw plug and the barb groove 212 of the screw head 12 are locked with each other, so that the state of the "necking" of the U-shaped groove 21 is realized, so as to improve the structural safety performance of the pedicle screw.

[0075] The pedicle screw fixing system of another embodiment of the present application comprises a connecting rod and a pedicle screw, the pedicle screw is the pedicle screw of the present application, the connecting rod is inserted into the U-shaped groove 21, and the pedicle screw further comprises a screw plug, and the screw is screwed in the U-shaped groove 21 and presses the connecting rod.

[0076] According to the pedicle screw fixing system of the embodiment of the present application, when the pedicle screw is implanted, the nail body 1 can be implanted into the vertebra first, and then the nail seat 2 is screwed on the nail body 1 from the screwing port 23. Since the nail seat 2 does not need to be installed before the nail body 1 is implanted, the implantation of the pedicle screw can be more flexible, and the interference and the shielding of the field of view of the nail seat 2 to the implantation of the nail body 1 are avoided, so as to facilitate the operation of the doctor during the operation and shorten the operation time. In addition, since the nail head 12 and the nail seat 2 are the matching structure of the spherical surface 121 and the ball groove 22, the nail body 1 can have a certain swing angle relative to the nail seat 2, and different implantation angles of the pedicle screw can be met, so as to facilitate the installation of the connecting rod.

[0077] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0078] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and do not connote or imply any relative importance or any meaning pertaining to the quantity of the features being described. Thus, a feature defined with "first", "second", etc. can include at least one of the features, explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0079] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connection", "fixing" and the like should be interpreted in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0080] In the present application, unless otherwise specifically defined and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0081] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the description, the illustrative representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0082] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. Changes, modifications, replacements and variations of the above embodiments made by those skilled in the art are within the scope of the present application.

Claims

1. A pedicle screw, characterized in that, The application relates to a pedicle screw, which comprises a nail body, a nail seat and a gasket. The nail body comprises a nail rod and a nail head connected with each other, the outer peripheral surface of the nail head is a spherical surface, and a first external thread is arranged on the spherical surface. The two ends of the nail seat are respectively provided with a U-shaped groove and a ball groove, the U-shaped groove is used for mounting a connecting rod, a first internal thread is arranged in the ball groove, one end of the ball groove away from the U-shaped groove is provided with a screw inlet, the nail head can be screwed into the ball groove through the screw inlet, and the nail head is in threaded connection with the ball groove. The gasket is arranged in the nail seat, at least part of the gasket extends into the ball groove and abuts against the nail head.

2. The pedicle screw of claim 1, wherein, A communication channel is arranged in the nail seat, the two ends of the communication channel are respectively communicated with the U-shaped groove and the ball groove, the gasket is arranged in the communication channel, one end of the gasket extends into the U-shaped groove and can abut against the connecting rod, and the other end of the gasket extends into the ball groove.

3. The pedicle screw of claim 2, wherein, The inner wall of the communication channel is provided with a convex structure, the outer wall of the gasket is provided with a groove, and the convex structure is matched in the groove to limit the gasket from being taken out of the nail seat.

4. The pedicle screw of claim 3, wherein, The groove is long-strip-shaped and extends along the axial direction of the nail seat, and the convex structure is in sliding connection with the groove along the axial direction of the nail seat. And / or, the pedicle screw further comprises an ejection member, the outer wall of the nail seat is provided with a locking hole, the locking hole extends along the radial direction of the nail seat, the inner end of the locking hole is spaced from the inner wall of the communication channel to form a thin wall part, the ejection member penetrates into the locking hole and extrudes the thin wall part, the thin wall part is deformed to form the convex structure.

5. The pedicle screw of claim 2, wherein, One end of the gasket has an arc-shaped supporting part which extends into the U-shaped groove and can abut against the connecting rod, and the other end of the gasket has a ball-shaped groove which abuts against the nail head.

6. The pedicle screw of claim 5, wherein, The width of the U-shaped groove is f1, the arc-shaped supporting part has an arc-shaped groove, and the width of the arc-shaped groove is f2, wherein 6.1mm<=f1<=6.5mm and 6.0mm<=f2<=6.4mm. And / or, the arc-shaped supporting part has an arc-shaped groove, and the two side bottom edges of the arc-shaped groove are respectively provided with a avoiding notch. And / or, the gasket is provided with a communication hole which penetrates through the gasket along the axial direction of the nail seat. And / or, the arc-shaped supporting part has an arc-shaped groove, and the depth of the arc-shaped groove is greater than or equal to the radius of the connecting rod.

7. The pedicle screw of claim 6, wherein, The gasket comprises a cylindrical body and a convex part which is symmetrically arranged on the two sides of the body along the radial direction of the body, the two convex parts are located below the arc-shaped groove, and the avoiding notch is arranged at the top end of the convex part.

8. The pedicle screw of claim 1, wherein, The pitch of the first external thread is p1, wherein 0.7mm<=p1<=1.5mm. And / or, the tooth width of the first external thread is m, wherein 0.2mm<=m<=0.8mm. And / or, the gap between the spherical surface and the ball groove is a, wherein 0.02mm<=a<=0.2mm. And / or, the gap between the diameter of the spherical surface and the large diameter of the first internal thread is b, wherein 0.02mm<=b<=0.6mm. And / or, the first external thread is a single thread, a double thread or a multi-thread; And / or, the cross section of the first external thread is a triangle, a trapezoid or a rectangle; And / or, the connecting position of the shank and the head has a transition round corner r, wherein 0.3mm≤r≤1.5mm; And / or, the distance between the center of the spherical surface and the rotation inlet is k, wherein 1.2mm≤k≤3.2mm; And / or, the end of the head away from the shank has a torx hole, and the bottom surface of the torx hole is a plane.

9. The pedicle screw of claim 1, wherein, The shank is provided with a second external thread, and the pitch of the second external thread is p2, wherein 0.8mm≤p2≤3.5mm; And / or, the shank is provided with a second external thread, and the second external thread includes a first section, a second section and a third section, which are arranged in order from the end away from the head to the end adjacent to the head, and the outer diameter of the first section and the third section gradually increases, and the outer diameter of the second section is constant; And / or, the end of the shank away from the head has a shank tip, and the shank tip is a pyramid structure; And / or, the shank is provided with a second external thread, and the second external thread is a single thread, a double thread or a single-double thread; And / or, the sidewall of the seat is provided with two lifting grooves, and the two lifting grooves are symmetrically arranged on both sides of the seat; And / or, the pedicle screw further includes a plug, the outer wall of the plug is provided with a third external thread, the inner wall of the U-shaped groove is provided with a third internal thread, the radially inner side of the third internal thread has a barb groove, the third external thread cooperates with the third internal thread and is locked with the barb groove; And / or, the seat is a short tail structure, a long tail structure or a minimally invasive structure.

10. A pedicle screw fixation system, characterized in that, It comprises: a connecting rod; a pedicle screw, the pedicle screw is the pedicle screw according to any one of claims 1-9, the connecting rod is inserted into the U-shaped groove, and the pedicle screw further includes a plug, the screw is screwed in the U-shaped groove and compresses the connecting rod.

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