A multi-axis nail and nail rod system

Abstract

The present invention proposes a multi-axis nail and nail rod system, including a universal nail cap, a pressure cap, a bone anchor and a thrust ring, wherein the interior of the universal nail cap is sequentially provided with an internal thread, a first inner hole and a second inner hole from one end to the other end, and the universal nail cap is provided with a notch in the radial direction; in the axial direction of the orthopedic rod, the first inner hole is cut off by the notch; in the direction perpendicular to the axial direction of the orthopedic rod, the inner diameter of the first inner hole is smaller than the inner diameter of the second inner hole; the inner diameter of the second inner hole in the axial direction of the orthopedic rod is larger than the inner diameter in the direction perpendicular to the axial direction of the orthopedic rod; the pressure cap is slidably arranged in the first inner hole and the second inner hole; a ball head is arranged at one end of the bone anchor, and the ball head is arranged inside the universal nail cap; the pressure cap and the thrust ring are relatively located on both sides of the ball head. The pressure cap in the present invention has good positioning effect and structural strength, and after being locked and fixed with the orthopedic rod, it is not easy to have the problem of component slippage and displacement, thereby significantly reducing the failure risk of the nail rod system.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a multi-axis nail and nail rod system. Background Art

[0002] The bone correction nail-rod system is a medical device used to treat and correct bone deformities or fractures, which usually includes a multi-axial nail and a correction rod. When used, it is necessary to drill holes in the patient's bones, then install the multi-axial nail, and after adjusting the posture of the multi-axial nail, place the correction rod on the multi-axial nail, then stretch and correct the bone, and then use screws to lock the correction rod on the multi-axial nail for fixation; usually, bone cement is also injected into the bone to ensure the stability of the structure.

[0003] The invention patent application with the publication number CN1371258A discloses a bottom-loaded multi-axial bone riveting device, including a receiving member, a crown member, a bone anchor and a retaining member. The receiving member defines an upper opening and a lower opening, a channel and a groove that can constitute a part of the same opening. The crown member and the bone anchor are installed in the lower opening of the receiving member, and the retaining member surrounds the bone anchor and is assembled in the groove of the receiving member.

[0004] Another invention patent application with application publication number CN116940292A discloses a bone anchor assembly, which provides a single bone anchor assembly. The bone anchor assembly includes an implantable stem and a receiver member having two spaced arms, the two spaced arms forming a U-shaped seat to receive a rod, and other components.

[0005] As in the above technical solution, the crown in CN1371258A plays the same role as the compression cap in CN116940292A, both of which are used to fix the orthopedic rod to the bone anchor. However, the crown in CN1371258A has a flat top surface, which creates less friction after contacting the orthopedic rod, and is prone to screw loosening and component displacement. Although the compression cap in CN116940292A has a cap rod slot at the top, it is an equal-diameter structure, which requires a non-threaded portion corresponding to the size of the compression cap to be opened inside the receiver for the compression cap to slide, and a larger notch needs to be reserved between the spaced arms to install the orthopedic rod, which reduces the overall strength of the receiver and reduces reliability. When the patient is exercising, it is easy to cause the components of the bone correction nail rod system to slip and displace. Summary of the invention

[0006] In view of this, the present invention proposes a multi-axis nail and nail rod system with a stable structure and components that are not prone to slippage and dislocation, thereby solving the problem of components being prone to slippage and displacement in existing nail rod systems.

[0007] The technical solution of the present invention is achieved in this way:

[0008] In one aspect, the present invention provides a multi-axis nail, comprising a universal nail cap, a pressure cap, a bone anchor and a thrust ring, wherein:

[0009] The universal nail cap is a cylindrical structure, and the interior of the universal nail cap is sequentially provided with an internal thread, a first inner hole, and a second inner hole from one end to the other end, and the universal nail cap is provided with a slot along the radial direction, and the slot is used to install the orthopedic rod;

[0010] In the axial direction of the orthopedic rod, the inner diameter of the first inner hole is cut off by the notch, and in the direction perpendicular to the axial direction of the orthopedic rod, the inner diameter of the first inner hole is smaller than the inner diameter of the second inner hole;

[0011] The inner diameter of the second inner hole in the axial direction of the orthopedic rod is greater than the inner diameter in the direction perpendicular to the axial direction of the orthopedic rod;

[0012] The pressing cap is slidably disposed in the first inner hole and the second inner hole, and a portion of the pressing cap extends into the notch;

[0013] A ball head is arranged at one end of the bone anchor, and the ball head is arranged inside the universal nail cap;

[0014] The pressure cap and the thrust ring are located on two sides of the ball head opposite to each other to limit the bone anchor.

[0015] On the basis of the above technical solution, preferably, it further includes a washer, and the universal nail cap is provided with a third inner hole, wherein,

[0016] The third inner hole is opened on a side of the second inner hole away from the first inner hole, and the inner diameter of the third inner hole is larger than the inner diameter of the second inner hole in a direction perpendicular to the axial direction of the orthopedic rod;

[0017] In the axial direction of the orthopedic rod, the inner diameters of the second inner hole and the third inner hole are the same;

[0018] The washer is arranged in the third inner hole and abuts against the pressure cap and the thrust ring, and the washer is made of elastic material.

[0019] On the basis of the above technical solution, preferably, the gasket is an annular structure, and a reinforcing rib is arranged inside the gasket;

[0020] The reinforcing rib is annular in structure, and a plurality of reinforcing ribs are arranged along the axial direction of the gasket;

[0021] A plurality of stepped platforms are arranged on one end of the ball head facing the pressing cap.

[0022] On the basis of the above technical solution, preferably, the pressure cap includes a first plug section and a second plug section, wherein:

[0023] A limiting groove is provided on the first plug-in section, the first plug-in section comprises an arc portion plugged into the first inner hole, and plane portions located on both sides of the arc portion, the plane portions abutting against the inner wall of the groove;

[0024] The second plug-in section and the first plug-in section are an integrated structure. The second plug-in section is plugged into the second inner hole and the third inner hole, and the second plug-in section abuts against the ball head.

[0025] In another aspect, the present invention provides a rod system comprising the above-mentioned multi-axial nail.

[0026] On the basis of the above technical solution, preferably, it further includes screws and connectors, wherein:

[0027] The screw is connected with the internal thread of the universal nail cap and presses the orthopedic rod;

[0028] The connecting piece is arranged on the screw, and is connected to the orthopedic rod, so as to realize the circumferential, radial and axial limitation of the orthopedic rod relative to the universal nail cap.

[0029] On the basis of the above technical solution, preferably, the orthopedic rod comprises a shell and an inner core, wherein:

[0030] The shell is an arc-shaped shell, the shell passes through the slot, and the opening of the shell faces the screw;

[0031] The inner core is arranged in the shell and is made of elastic material.

[0032] On the basis of the above technical solution, preferably, the connecting piece is a threaded column, the threaded column is a conical structure, the threaded column is arranged on the screw, and the threaded column passes through the opening of the shell and cooperates with the inner core through a thread.

[0033] On the basis of the above technical solution, preferably, the connecting member includes a pressure ring and a limit rod, wherein:

[0034] The pressing ring is rotatably arranged on the screw, and a pressing groove is provided at one end of the pressing ring away from the screw;

[0035] The limiting rod is connected to the pressing ring, and the limiting rod is located in the pressing groove;

[0036] The limiting rod passes through the opening of the shell and abuts against the inner core.

[0037] On the basis of the above technical solution, preferably, it further comprises a limit block, the universal nail cap is provided with an embedding groove, the limit block is arranged on the outer wall of the orthopedic rod, and the limit block is embedded in the embedding groove.

[0038] The multi-axis nail and nail rod system of the present invention has the following beneficial effects compared with the prior art:

[0039] (1) By setting the inner hole of the universal nail cap as a stepped hole structure, and partially extending the pressure cap into the notch of the universal nail cap, and the second inner hole and the third inner hole are equal-diameter structures in the axial direction of the orthopedic rod, after the pressure cap adapted to the shape of the inner hole of the universal nail cap is assembled into the universal nail cap, the pressure cap will have a larger area to contact with the orthopedic rod, and the friction between the two will be larger, which will have a good positioning effect and structural strength, and the problem of component slippage and displacement will not easily occur, thereby significantly reducing the failure risk of the nail rod system;

[0040] (2) A third inner hole is provided in the universal nail cap, and a washer is provided in the third inner hole. Thus, after the universal nail cap is turned relative to the bone anchor, the washer can always maintain good friction force to ensure the stable position of the universal nail cap relative to the bone anchor;

[0041] (3) By providing reinforcing ribs in the washer and providing a plurality of stepped platforms on the ball head, the position stability can be further improved by relying on the cooperation between the edges of the ball head and the washer. At the same time, the reinforcing ribs can ensure the structural strength of the washer. Since the reinforcing ribs are annular structures and multiple reinforcing ribs are provided along the axial direction of the washer, the multiple reinforcing ribs do not interfere with each other, ensuring that they can deform and displace following the extrusion of the ball head, so as to achieve full positioning of the universal nail cap relative to the ball head;

[0042] (4) By setting the pressing cap as the first plug-in section and the second plug-in section, the pressing cap as a whole has a stepped cylindrical structure, which is convenient for positioning when assembled into the universal nail cap, and the flat surface of the first plug-in section extends into the slot and abuts against the inner wall of the slot, so that a larger area is provided for contact with the orthopedic rod, which can increase the friction force and ensure that the orthopedic rod is in a stable position after being locked;

[0043] (5) By configuring the orthopedic rod to consist of a shell and an inner core, and providing a threaded column on the screw that matches the inner core, the connection stability between the screw and the orthopedic rod can be further improved, so as to fully realize the positioning of the orthopedic rod and avoid the problems of axial movement and circumferential rotation of the orthopedic rod; at the same time, the threaded column is a conical structure, and as the screw is tightened, it will expand the opening of the shell, so that the shell can fully resist the notches of the pressure cap and the universal nail cap, further improving the assembly stability;

[0044] (6) By arranging a compression ring and a limiting rod on the screw, when the screw is tightened, the shell of the orthopedic rod can be compressed by the compression ring, the inner core of the orthopedic rod is compressed, and the opening of the shell is relatively closed, so that the limiting rod can be clamped, thereby improving the stability of the connection between the screw and the orthopedic rod, so that the orthopedic rod is not easy to fall off the universal nail head, thereby ensuring the application stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 is a three-dimensional diagram of the multi-axis nail of the present invention;

[0047] Figure 2 It is a front view of the multi-axis nail of the present invention;

[0048] Figure 3 For the present invention Figure 2 Middle AA section view;

[0049] Figure 4 is a side view of the multi-axis nail of the present invention;

[0050] Figure 5 For the present invention Figure 4 Middle BB section;

[0051] Figure 6 An exploded view of the multi-axis nail of the present invention;

[0052] Figure 7 A three-dimensional diagram of a universal nail cap of a multi-axis nail of the present invention;

[0053] Figure 8 It is a cross-sectional view of the universal nail cap of the multi-axis nail of the present invention;

[0054] Fig. 9 A cross-sectional view of the universal nail cap of the multi-axis nail of the present invention from a second viewing angle;

[0055] Fig.10 A three-dimensional diagram of a pressure cap of a multi-axis nail of the present invention;

[0056] Fig.11 is a three-dimensional diagram of the nail rod system of the present invention;

[0057] Fig.12 A front view of a single multi-axial nail of the nail rod system of the present invention;

[0058] Fig.13 For the present invention Fig.12 Mid-CC section;

[0059] Fig.14 A side view of a single multi-axial nail of the nail rod system of the present invention;

[0060] Fig.15 For the present invention Fig.14 Middle DD section;

[0061] Fig.16 It is a structural diagram of the separation of the universal nail cap and the orthopedic rod of the nail rod system of the present invention;

[0062] Fig.17 A structural diagram of the separation of the orthopedic rod and the screw of the nail-rod system of the present invention;

[0063] Fig.18 The assembly structure diagram of the connecting member of the nail rod system of the present invention adopts a threaded column;

[0064] Fig.19 The present invention is a structural diagram of an assembly of a connecting member of a nail-rod system using a pressure ring and a limit rod;

[0065] Fig. 20 A cross-sectional view of the segmented arrangement of the inner core in the orthopedic rod of the nail-rod system of the present invention;

[0066] In the figure: 1. universal nail cap; 101. internal thread; 102. first inner hole; 103. second inner hole; 104. third inner hole; 105. notch; 106. embedded groove; 2. pressing cap; 21. first plug-in section; 211. arc-shaped portion; 212. plane portion; 22. second plug-in section; 201. limiting groove; 3. bone anchor; 31. ball head; 32. step platform; 4. thrust ring; 5. washer; 51. reinforcing rib; 6. orthopedic rod; 61. shell; 62. inner core; 601. anti-slip pattern; 7. screw; 8. threaded column; 9. pressing ring; 901. pressing groove; 10. limiting rod; 11. limiting block. DETAILED DESCRIPTION

[0067] The following will be combined with 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, not all of the embodiments. 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.

[0068] like Figures 1 to 20 As shown, the multi-axis nail of the present invention comprises a universal nail cap 1, a pressure cap 2, a bone anchor 3, a thrust ring 4, a washer 5 and an orthopedic rod 6;

[0069] The nail-rod system of the present invention comprises the above-mentioned multi-axis nail, and also comprises a screw 7 , a threaded column 8 , a pressure ring 9 , a limiting rod 10 and a limiting block 11 .

[0070] like Figures 1 to 9As shown, the universal nail cap 1 is a cylindrical structure, and the interior of the universal nail cap 1 is sequentially provided with an internal thread 101, a first inner hole 102, and a second inner hole 103 from one end to the other end. The universal nail cap 1 is provided with a notch 105 along the radial direction, and the notch 105 is used to install the orthopedic rod 6; in the axial direction of the orthopedic rod 6, the first inner hole 102 is cut off by the notch 105; in the direction perpendicular to the axial direction of the orthopedic rod 6, the inner diameter of the first inner hole 102 is smaller than that of the second inner hole 103. The inner diameter of the second inner hole 103 in the axial direction of the orthopedic rod 6 is greater than the inner diameter in the direction perpendicular to the axial direction of the orthopedic rod 6; the pressure cap 2 is slidably arranged in the first inner hole 102 and the second inner hole 103, and the pressure cap 2 partially extends into the notch 105; a ball head 31 is arranged at one end of the bone anchor 3, and the ball head 31 is arranged inside the universal nail cap 1; the pressure cap 2 and the thrust ring 4 are located on both sides of the ball head 31 to limit the bone anchor 3;

[0071] As in the above structure, during assembly, the pressure cap 2 is first assembled into the universal nail cap 1, and then the bone anchor 3 is placed, and then the thrust ring 4 is assembled to fix it; wherein the thrust ring 4 is set as a C-shaped ring, and the inner part of the universal nail cap 1 is provided with a ring groove corresponding to the thrust ring 4, and the thrust ring 4 is compressed and pushed into the ring groove, so that the ball head 31 of the bone anchor 3 can be locked;

[0072] The bone anchor 3 is used to connect the patient's bones, and then the universal nail cap 1 is adjusted in posture. At this time, the universal nail cap 1 rotates relative to the bone anchor 3 to adjust the direction. Then, the orthopedic rod 6 is assembled into the slot 105, and the orthopedic rod 6 is locked by fasteners such as screws and plugs, so that the orthopedic rod 6 applies pressure to the pressure cap 2, and the pressure cap 2 presses the ball head 31 to achieve fixation;

[0073] In this structure, the second inner hole 103 for assembling the pressure cap 2 is an unequal diameter structure, which has a larger width in the axial direction of the corresponding orthopedic rod 6. Therefore, the corresponding pressure cap 2 is configured to adapt to the shape of the second inner hole 103, that is, the pressure cap 2 has a larger wall thickness in the axial direction of the orthopedic rod 6.

[0074] At the same time, a part of the pressing cap 2 extends into the notch 105, so that the universal nail cap 1 can provide a stable support to the pressing cap 2, and the pressing cap 2 and the orthopedic rod 6 have a larger contact area, thereby improving the friction. In this way, after the orthopedic rod 6 is compressed by fasteners such as screws and plugs, the orthopedic rod 6 can be better limited, and the problem of component slippage and limitation is not likely to occur;

[0075] In the application process of nail rod system, Fig.11 As shown, a plurality of multi-axial nails are usually arranged to fix the same orthopedic rod 6 to form a single nail-rod system, and then two rows of nail-rod systems are arranged in parallel, and then a transverse fixing piece is arranged to connect the orthopedic rods in the two nail-rod systems, thereby achieving a stable structure.

[0076] Specifically, when fixing the bone anchor 3, bone cement may be injected into the bone to ensure the stability of the installation of the bone anchor 3; at the same time, the bone anchor 3 may be provided with an internal through hole to facilitate the injection of bone cement.

[0077] Specifically, the universal nail cap 1, the bone anchor 3 and the orthopedic rod 6 are made of cobalt-chromium-molybdenum material.

[0078] Specifically, the bone anchor 3 is fixed by an external thread, and the external thread adopts a double-row thread with different pitches.

[0079] like Figures 5 to 9 As shown, the universal nail cap 1 is provided with a third inner hole 104, wherein the third inner hole 104 is provided on a side away from the second inner hole 103, and in a direction perpendicular to the axial direction of the orthopedic rod 6, the inner diameter of the third inner hole 104 is greater than the inner diameter of the second inner hole 103; in the axial direction of the orthopedic rod 6, the inner diameters of the second inner hole 103 and the third inner hole 104 are the same, a washer 5 is arranged in the third inner hole 104, and the washer 5 abuts against the pressure cap 2 and the thrust ring 4, and the washer 5 is made of elastic material;

[0080] As in the above structure, since the universal nail cap 1 needs to be rotated relative to the bone anchor 3 to adjust the posture during correction, a washer 5 is provided to increase the friction force;

[0081] In such a solution, the third inner hole 104 is of an equal diameter structure, which facilitates the installation of the gasket 5 and limits the position of the gasket 5 to ensure the stability of the position of the gasket 5, thereby achieving the clamping of the ball head 31.

[0082] In some embodiments, the third inner hole 104 is also configured as an unequal diameter structure. Specifically, based on the above solution, the inner diameter of the third inner hole 104 in the axial direction of the orthopedic rod 6 is enlarged;

[0083] In this way, after the washer 5 is assembled into the third inner hole 104, in the direction perpendicular to the axial direction of the orthopedic rod 6, the two sides of the washer 5 will abut against the inner wall of the third inner hole 104, and in the axial direction of the orthopedic rod 6, there will be a gap between the two sides of the washer 5 and the third inner hole 104. When the ball head 31 of the bone anchor 3 rotates, the washer 5 has a certain deformation space, thereby ensuring the convenience of adjusting the universal nail cap 1. After the universal nail cap 1 is adjusted into place, the washer 5 will still hold the ball head 31 tightly, which can improve the limiting effect of the universal nail cap 1 relative to the bone anchor 3, and facilitate the subsequent assembly of the orthopedic rod 6.

[0084] In some embodiments, the inner diameter of the third inner hole 104 in a direction perpendicular to the axial direction of the orthopedic rod 6 may also be enlarged.

[0085] In some embodiments, small protrusions are provided on the surface of the ball head 31 to better fit the washer 5, thereby ensuring friction;

[0086] Specifically, assuming that the end of the pressure cap 2 faces the thrust ring 4, and the distance between the pressure cap 2 and the thrust ring 4 is X1, the axial length of the washer 5 is set to be greater than X1. In this way, when the thrust ring 4 is assembled, the thrust ring 4 appropriately compresses the washer 5, which can make the washer 5 have a tightening effect to ensure the relative positioning of the universal nail cap 1 and the bone anchor 3. When the posture of the universal nail cap 1 is adjusted and the orthopedic rod 6 is installed, the universal nail cap 1 is not easy to deviate from the predetermined posture.

[0087] like Figure 5 As shown, the gasket 5 is an annular structure, and a reinforcing rib 51 is arranged inside the gasket 5; the reinforcing rib 51 is an annular structure, and a plurality of reinforcing ribs 51 are arranged along the axial direction of the gasket 5; a plurality of stepped platforms 32 are arranged at one end of the ball head 31 facing the pressure cap 2;

[0088] As in the above structure, when the washer 5 is provided, a plurality of reinforcing ribs 51 are provided inside the washer 5, and the structural strength of the washer can be ensured by relying on the reinforcing ribs 51. At the same time, since the reinforcing ribs 51 are annular structures and a plurality of them are provided along the axial direction of the washer 5, the plurality of reinforcing ribs 51 do not interfere with each other and can be deformed and displaced following the extrusion of the ball head 31, so as to achieve full positioning of the universal nail cap 1 relative to the ball head 31;

[0089] Specifically, a plurality of stepped platforms 32 are provided on the ball head 31, so that the friction force can be increased by the cooperation between the edges of the stepped platforms 32 and the washers 5, thereby further improving the position stability of the universal nail cap 1;

[0090] In some embodiments, the step terraces 32 are replaced by fine protrusions.

[0091] like Figures 8 to 10 As shown, the pressing cap 2 includes a first plug-in section 21 and a second plug-in section 22, wherein a limiting groove 201 is provided on the first plug-in section 21, and the first plug-in section 21 includes an arc portion 211 plugged into the first inner hole 102, and flat portions 212 located on both sides of the arc portion 211, and the flat portions 212 abut against the inner wall of the notch 105; the second plug-in section 22 and the first plug-in section 21 are an integrated structure, the second plug-in section 22 is plugged into the second inner hole 103 and the third inner hole 104, and the second plug-in section 22 abuts against the ball head 31;

[0092] As in the above structure, the overall shape of the pressing cap 2 is adapted to the inner hole shape of the universal nail cap 1; wherein the limiting groove 201 on the first plug section 21 is used to abut against the orthopedic rod 6 to perform preliminary positioning of the orthopedic rod 6;

[0093] Specifically, the first plug section 21 has two parts, namely, an arc portion 211 and a flat portion 212, wherein the arc portion 211 cooperates with the first inner hole 102, and the flat portion 212 extends into the slot 105 and abuts against the inner wall of the slot 105. This structure increases the wall thickness of the first plug section 21 in the axial direction of the orthopedic rod 6, thereby stably abutting against the orthopedic rod 6 and increasing the friction force.

[0094] At the same time, this structure also allows the slot 105 and the inner wall of the first inner hole 102 to stably support the first plug-in section 21. After the orthopedic rod 6 is assembled, the orthopedic rod 6 cooperates with the inner wall of the universal nail cap 1 to clamp the first plug-in section 21. Therefore, even in the axial direction of the vertical orthopedic rod 6, the wall thickness of the first plug-in section 21 is relatively thin, and it also has good application strength and is not prone to rupture, thereby ensuring the stability of the overall application.

[0095] like Figures 11 to 19 As shown, the screw 7 is connected to the internal thread 101 of the universal nail cap 1 and presses the orthopedic rod 6; the connecting piece is arranged on the screw 7, and the connecting piece is connected to the orthopedic rod 6 to achieve circumferential, radial and axial limitation of the orthopedic rod 6 relative to the universal nail cap 1;

[0096] As in the above structure, the conventional nail-rod system only relies on fasteners such as screws and plugs to press and fix the orthopedic rod 6. However, due to factors such as the patient's movement, the risk of loosening and slipping of the components is prone to occur. Therefore, in the screw 7 of the present solution, a connecting piece is also provided to further fix the orthopedic rod 6. This structure improves the integrity of the screw 7 and the orthopedic rod 6 and reduces the risk of slipping.

[0097] When the screw 7 is used, the screw 7 is matched with the internal thread 101 of the universal nail cap 1, and pressure is applied to the pressure cap 2, and the pressure cap 2 applies pressure to the ball head 31 until the screw 7 is tightened, thereby achieving the locking and positioning of the above-mentioned components.

[0098] like Fig.12 and Fig.13 As shown, the orthopedic rod 6 includes a shell 61 and an inner core 62, wherein the shell 61 is an arc-shaped shell, the shell 61 passes through the notch 105, and the opening of the shell 61 faces the screw 7; the inner core 62 is disposed in the shell 61, and the inner core 62 is made of elastic material;

[0099] As described above, the orthopedic rod 6 has a shell 61 and an inner core 62, and the inner core 62 is made of elastic material, while the shell 61 is an arc-shaped structure with an opening, so that when the screw 7 is locked, the shell 61 is slightly deformed, thereby compressing the inner core 62, and the tensioning effect is achieved by elastic force, thereby ensuring a better pressing effect of the screw 7 and making it less likely to loosen;

[0100] Specifically, the shell 61 and the inner core 62 are connected by a reliable structure, for example, by bonding;

[0101] In some embodiments, Fig. 20 As shown, the inner core 62 is not configured as a strip structure, but as a plurality of block structures. The inner cores 62 of the plurality of block structures are arranged inside the shell 61 along the axial direction, and the gaps between the inner cores 62 and the inner cores 62 are filled by the extension of the shell 61. When the inner core 62 is configured, it can be formed by injection molding into the shell 61. In this way, the axial limitation of the inner core 62 relative to the shell 61 can be effectively achieved, thereby making the structure more stable.

[0102] In some embodiments, the shell 61 adopts a bamboo structure, that is, the shell 61 can undergo a certain radial compression deformation with the support of the inner core 62. This deformation is only reflected in the change of the inner diameter of the shell 61 and the inner core 62, but it has good structural strength in the axial direction, thereby preventing the problem of bone displacement.

[0103] Regarding the structural setting of the connector, this solution provides two structures:

[0104] First, if Fig.18 As shown, the connecting member is a threaded column 8, which is a conical structure. The threaded column 8 is arranged on the screw 7, and the threaded column 8 passes through the opening of the housing 61 and is matched with the inner core 62 through a thread.

[0105] As in the above structure, when the screw 7 cooperates with the internal thread 101 for locking, the threaded column 8 will pass through the opening of the shell 61 and be screwed with the inner core 62, so that not only the locking limit of the orthopedic rod 6 can be achieved by the pressing force of the screw 7, but also the axial and circumferential limit of the orthopedic rod 6 can be better achieved by relying on the cooperation between the threaded column 8 and the inner core 62;

[0106] At the same time in this structure, since the threaded column 8 is a conical structure, as the screw 7 is tightened, the threaded column 8 will expand the opening of the shell 61 so that the shell 61 can fully support the notches 105 of the pressure cap 2 and the universal nail cap 1, further improving the assembly stability.

[0107] Second, if Figures 11 to 17 , Fig.19 As shown, the connecting member includes a pressing ring 9 and a limiting rod 10, wherein the pressing ring 9 is rotatably arranged on the screw 7, and a pressing groove 901 is provided at one end of the pressing ring 9 away from the screw 7; the limiting rod 10 is connected to the pressing ring 9, and the limiting rod 10 is located in the pressing groove 901; the limiting rod 10 passes through the opening of the housing 61 and abuts against the inner core 62;

[0108] As in the above structure, when the screw 7 is assembled, the limiting rod 10 will extend through the opening of the shell 61. As the screw 7 continues to be tightened, the pressing groove 901 of the pressing ring 9 will press the shell 61. At this time, the inner core 62 is compressed, and the shell 61 is slightly deformed. The opening edge of the shell 61 will clamp the limiting rod 10, thereby realizing the axial positioning of the screw 7 and the limiting rod 10, which can reduce the risk of the screw 7 slipping off, and at the same time, it can also improve the axial limitation of the orthopedic rod 6.

[0109] In order to avoid the problem of rotation interference, the pressure ring 9 is connected to the screw 7 in a rotational manner, so that after the pressure groove 901 of the pressure ring 9 is engaged with the orthopedic rod 6, the pressure ring 9 will no longer rotate, but move along the axial direction to press the orthopedic rod 6;

[0110] Specifically, the limiting rod 10 is provided with a T-shaped rod, and the protruding ends on both sides of the limiting rod 10 extend into the shell 61 , so that the shell 61 has better clamping stability for the limiting rod 10 .

[0111] In some embodiments, the pressure ring 9 is fixed to the screw 7 by glue. When the orthopedic rod 6 abuts against the pressure cap 2, the end of the universal nail cap 1 away from the bone anchor 3 is spaced X2 from the top of the shell 61, the compressible distance of the inner core 62 is X3, and the axial length of the screw 7 is X4. Then, the length of the limit rod 10 in the axial direction of the screw 7 should be greater than X2, and X3 should be greater than X4.

[0112] In such a structure, before the screw 7 is matched with the internal thread 101 of the universal nail cap 1, the limiting rod 10 can be inserted into the opening of the housing 61, so as to circumferentially position the limiting rod 10 and the pressing ring 9. Since the pressing ring 9 and the screw 7 are fixed by glue, the screw 7 can be rotated at this time to loosen the glue point. Under the condition that the pressing ring 9 and the limiting rod 10 are circumferentially limited, the screw 7 can continue to rotate to threadably match with the internal thread 101 until it is locked and fixed.

[0113] At the same time, as the screw 7 , the pressure ring 9 and the limiting rod 10 move, they will compress the inner core 62 so that the screw 7 is completely immersed in the notch 105 .

[0114] In some embodiments, the limiting rod 10 is set shorter, so that when assembling, the orthopedic rod 6 can be lifted first, and after the limiting rod 10 is plugged into the housing 61, the screw 7 is rotated to cooperate with the internal thread of the universal nail cap 1 to press the orthopedic rod 6 down. Fig. 20 As shown, the opening edge of the shell 61 is provided with anti-slip grooves 601, so that after the threaded column 8 or the limiting rod 10 passes through the opening of the shell 61, the threaded column 8 or the limiting rod 10 can have better friction with the shell 61, thereby improving the axial limiting effect and further improving the stability of the structural assembly.

[0115] like Fig.16 and Fig.17As shown, a slot 106 is provided on the universal nail cap 1, and a limit block 11 is arranged on the outer wall of the orthopedic rod 6, and the limit block 11 is fitted into the slot 106;

[0116] As in the above structure, when the nail-rod system is used, a plurality of bone anchors 3 and universal nail caps 1 are provided, and the orthopedic rod 6 passes through the slots 105 of the plurality of universal nail caps 1. The orthopedic rod 6 can be initially limited by the stopper 11 on the outer wall of the orthopedic rod 6 cooperating with the embedded slot 106 of the universal nail cap 1, thereby ensuring the correct installation position of the orthopedic rod 6.

[0117] Specifically, the limiting block 11 is provided at one location on the outer wall of the orthopedic rod 6 , or is symmetrically provided at two locations on the orthopedic rod 6 , for initial positioning.

[0118] Specific implementation steps:

[0119] When used, holes are drilled on the patient's bones and multiple bone anchors 3 are installed. Then, the posture of the universal nail cap 1 is corrected, and then the orthopedic rod 6 is placed into the universal nail cap 1. At this time, the orthopedic rod 6 will abut against the pressure cap 2, and the pressure cap 2 abuts against the ball head 31 of the bone anchor 3. Then, the patient's bones are stretched and corrected. After the correction is in place, the screw 7 is installed in the universal nail cap 1. As the screw 7 is tightened in cooperation with the internal thread 101, the orthopedic rod 6 and the pressure cap 2 are pressed to achieve relative positioning of the orthopedic rod 6, the bone anchor 3, the pressure cap 2 and the universal nail cap 1.

[0120] During the tightening process of the screw 7 , the threaded column 8 or the limiting rod 10 used as a connecting member will cooperate with the orthopedic rod 6 to fully position the orthopedic rod 6 .

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A nail rod system, characterized in that: The invention comprises a multi-axial nail, a screw (7) and a connecting piece, wherein the multi-axial nail comprises a universal nail cap (1), a pressure cap (2), a bone anchor (3) and a thrust ring (4), wherein: The universal nail cap (1) is a cylindrical structure, and the interior of the universal nail cap (1) is provided with an internal thread (101), a first inner hole (102) and a second inner hole (103) in sequence from one end to the other end. The universal nail cap (1) is provided with a notch (105) along the radial direction, and the notch (105) is used to install the orthopedic rod (6); In the axial direction of the orthopedic rod (6), the first inner hole (102) is cut off by the notch (105), and in a direction perpendicular to the axial direction of the orthopedic rod (6), the inner diameter of the first inner hole (102) is smaller than the inner diameter of the second inner hole (103); The inner diameter of the second inner hole (103) in the axial direction of the orthopedic rod (6) is greater than the inner diameter in the direction perpendicular to the axial direction of the orthopedic rod (6); The pressing cap (2) is slidably disposed in the first inner hole (102) and the second inner hole (103), and the pressing cap (2) partially extends into the notch (105); A ball head (31) is provided at one end of the bone anchor (3), and the ball head (31) is arranged inside the universal nail cap (1); The pressing cap (2) and the thrust ring (4) are located oppositely on two sides of the ball head (31) to limit the position of the bone anchor (3); The screw (7) is connected to the internal thread (101) of the universal nail cap (1) and presses the orthopedic rod (6); the connecting piece is arranged on the screw (7) and connected to the orthopedic rod (6) to achieve circumferential, radial and axial positioning of the orthopedic rod (6) relative to the universal nail cap (1); The orthopedic rod (6) comprises a shell (61) and an inner core (62), wherein the shell (61) is an arc-shaped shell, the shell (61) passes through the notch (105), and the opening of the shell (61) faces the screw (7), and the connecting member passes through the opening of the shell (61); the inner core (62) is arranged in the shell (61), and the inner core (62) is made of elastic material.

2. The nail rod system according to claim 1, characterized in that: It also includes a washer (5), and the universal nail cap (1) is provided with a third inner hole (104), wherein: The third inner hole (104) is opened on a side of the second inner hole (103) away from the first inner hole (102), and in a direction perpendicular to the axial direction of the orthopedic rod (6), the inner diameter of the third inner hole (104) is greater than the inner diameter of the second inner hole (103); In the axial direction of the orthopedic rod (6), the inner diameters of the second inner hole (103) and the third inner hole (104) are the same; The washer (5) is arranged in the third inner hole (104), and the washer (5) abuts against the pressure cap (2) and the thrust ring (4), and the washer (5) is made of elastic material.

3. The nail rod system according to claim 2, characterized in that: The gasket (5) is an annular structure, and a reinforcing rib (51) is provided inside the gasket (5); The reinforcing rib (51) is an annular structure, and a plurality of the reinforcing ribs (51) are arranged along the axial direction of the gasket (5); A plurality of stepped platforms (32) are provided at one end of the ball head (31) facing the pressing cap (2).

4. The nail rod system according to claim 3, characterized in that: The pressing cap (2) comprises a first plug-in section (21) and a second plug-in section (22), wherein: A limiting groove (201) is provided on the first plug-in section (21), the first plug-in section (21) comprising an arc-shaped portion (211) plugged into the first inner hole (102), and flat portions (212) located on both sides of the arc-shaped portion (211), the flat portions (212) abutting against the inner wall of the notch (105); The second plug-in section (22) and the first plug-in section (21) are an integrated structure; the second plug-in section (22) is plugged into the second inner hole (103) and the third inner hole (104), and the second plug-in section (22) abuts against the ball head (31).

5. The nail rod system according to claim 1, characterized in that: The connecting piece is a threaded column (8), the threaded column (8) is a conical structure, the threaded column (8) is arranged on the screw (7), and the threaded column (8) passes through the opening of the shell (61) and is threadably matched with the inner core (62).

6. The nail rod system according to claim 1, characterized in that: The connecting member comprises a pressure ring (9) and a limiting rod (10), wherein: The pressing ring (9) is rotatably arranged on the screw (7), and a pressing groove (901) is formed at one end of the pressing ring (9) away from the screw (7); The limiting rod (10) is connected to the pressing ring (9), and the limiting rod (10) is located in the pressing groove (901); The limiting rod (10) passes through the opening of the shell (61) and abuts against the inner core (62).

7. The nail rod system according to claim 1, characterized in that: It also comprises a limit block (11), the universal nail cap (1) is provided with an embedding groove (106), the limit block (11) is arranged on the outer wall of the orthopedic rod (6), and the limit block (11) is embedded in the embedding groove (106).

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