A dynamic stabilization structure for spinal surgery

Abstract

The present invention relates to a dynamic stabilization structure for spinal surgery, the dynamic stabilization structure comprises a dynamic pedicle screw, the dynamic pedicle screw comprises a first joint part, a second joint part and a third joint part; the first joint part comprises a stud, a thread and a joint head; the second joint part comprises a first sliding part, a first interlayer and a cover plate; the first interlayer is placed in a first accommodating cavity in the first sliding part, and the joint head is placed in a second accommodating cavity in the first interlayer; the cover plate is placed on an end of the first sliding part away from the stud thread; the third joint part comprises a second sliding part and a fixing plate, the second joint part is placed in a third accommodating cavity of the second sliding part, two fixing plates are symmetrically arranged on the second sliding part, a fixing groove is formed between the two fixing plates, a screwdriver is inserted into the fixing groove, the screwdriver head is placed in a first groove, and the dynamic pedicle screw is anchored on the spine. The present invention can retain the free activity of the fixed spinal segment and prevent the dynamic pedicle screw from breaking due to fatigue.

Description

Technical Field

[0001] The invention relates to the field of spinal surgery internal fixation systems, and in particular to a dynamic stabilization structure used in spinal surgery. Background Art

[0002] Pedicle screw-rod fixation has become an important intervention for the surgical treatment of spinal diseases such as spinal instability, degenerative diseases, vertebral fractures, malignant tumors, spinal deformities and infections. The traditional pedicle screw-rod system is a rigid fixation system that causes spinal fusion after use. One of the most important disadvantages of rigid fixation and fusion is the reduced range of motion of the fused segment. In addition, adjacent segment degeneration is another important postoperative complication. Dynamic stabilization structures can be used as an alternative to rigid spinal fixation surgery, thereby helping to reduce the incidence of adjacent segment degeneration and maintain the motion and functional state of the spine under physiological conditions. Currently, the commonly used dynamic stabilization structures are mainly dynamic stabilization connecting rods, which use elastic connecting rods instead of rigid connecting rods to allow the pedicle screw-rod system to retain some range of motion. Commonly used dynamic stabilization connecting rods include the Dynesys system, the K-ROD system, and the Isobar system.

[0003] The Dynesys dynamic stabilization system consists of a polycarbonate polyurethane flexible connecting rod, a polyethylene terephthalate axial strip, and a titanium alloy pedicle screw. The length of the polycarbonate polyurethane flexible connecting rod can be adjusted according to clinical needs. The polyethylene terephthalate axial strip can pass through the head of the pedicle screw. The flexible connecting rod can be implanted after preloading. The Dynesys system can achieve satisfactory clinical efficacy, but mild pedicle screw loosening, adjacent segment degeneration, and pedicle screw fracture with low back pain can also occur during postoperative follow-up. In addition, the extension of the flexible connecting rod can increase spinal mobility and reduce the load on the facet joints. The Dynesys system axial strip can generate greater distraction stress in the sagittal plane, while the distraction force in the transverse plane is significantly insufficient. The stiffness of the spinal fixation system of the posterior bony unit is not only related to the stress distribution of the pedicle, but also affects the stress distribution of the vertebral body. In the Dynesys system, less load acts on the posterior bony unit, which leads to more obvious stress concentration around the pedicle screws, which can easily lead to internal fixation fracture. In addition, its use process is relatively cumbersome and requires intraoperative assembly of various components, which further limits its clinical application.

[0004] The K-ROD system consists of titanium alloy pedicle screws, two titanium alloy cable connecting rods, and two polyaryletherketone flexible connecting rods. The polyaryletherketone connecting rods in the K-ROD system have higher torsional stiffness than the polycarbonate polyurethane flexible connecting rods in the Dynesys system. The restriction of the bridging segment on the facet joint contact will cause overcompensation of the facet joint contact of the adjacent segment. The results of the study showed that the K-ROD system will increase the load on the facet joints of the adjacent segments in all directions of movement. Compared with the Dynesys system, the K-ROD system can reduce the range of higher stress distribution around the pedicle screws in the flexion state. This system cannot be effectively bent according to the spinal curvature, and after cutting, the internal structure of the connecting rod will be destroyed, affecting its mechanical properties. Therefore, it still has shortcomings.

[0005] The Isobar system is a semi-rigid stabilization system. It is mainly composed of universal pedicle screws and two dynamic connecting rods. The key moving part of the dynamic connecting rod is a unique shock-absorbing structure composed of internally superimposed titanium rings. The range of motion of the shock-absorbing structure is similar to the physiological range of motion of the spine. The semi-rigid internal fixation device mainly relies on the pedicle screws to bear the load generated when the fixed segment moves in different directions and planes, thereby ensuring that the fixed segment has a certain range of motion. The application of the Isobar dynamic stabilization system can produce a good therapeutic effect on the treatment of double-segment lumbar degenerative diseases. The semi-rigid internal fixation system based on pedicle screws can reduce the pressure on the intervertebral joints and protect the intervertebral joints of the non-fused segments. It bears the stress generated by the internal fixation segment in different directions and motion planes, disperses the axial stress of the spine and the shear force during flexion and extension to the intervertebral disc, and stabilizes the lumbar structure while maintaining a certain degree of lumbar range of motion. However, this system is not suitable for long-segment fixation and cannot be bent according to the actual spinal curvature requirements, which limits its clinical application. In addition, the above-mentioned dynamic stabilization system can only be used for the lumbar spine, not for the cervical spine and thoracic spine, which limits its scope of clinical application. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a dynamic stabilization structure for spinal surgery, which can be applied to cervical, thoracic, lumbar spine surgery, long segment spine surgery and simulation training of spinal surgery. After implantation, the fixed spinal segment can retain the mobility, reduce the stress concentration phenomenon of the internal fixation system, and reduce the risk of adjacent segment degeneration and the risk of internal fixation fracture. The dynamic pedicle screw cooperates with the dynamic rod to achieve accurate placement of the dynamic rod after bending according to the spinal curvature.

[0007] The specific technical solutions of the present invention are as follows:

[0008] A dynamic stabilization structure for spinal surgery, the dynamic stabilization structure comprising a dynamic pedicle screw, the dynamic pedicle screw comprising a first joint component, a second joint component and a third joint component;

[0009] The first joint component includes a stud, a thread and a first joint head; the thread is arranged on the stud, the first joint head is sleeved on one end of the stud, and the stud is provided with a first groove for accommodating a screwdriver head of a screwdriver;

[0010] The second joint component comprises a first sliding component, a first interlayer and a cover plate; the first interlayer is placed in a first accommodating cavity in the first sliding component, the first interlayer has a second accommodating cavity, and the first joint head is placed in the second accommodating cavity; the cover plate is placed on an end of the first sliding component away from the thread of the stud;

[0011] The third joint component includes a second sliding component and a fixing plate. The second sliding component has an end face at one end. The second sliding component includes a third accommodating cavity on one side of the end face. The second joint component is placed in the third accommodating cavity. The two fixing plates are symmetrically arranged at the other end of the second sliding component. A fixing groove is formed between the two fixing plates. The screwdriver is inserted into the fixing groove, passes through the cover plate and sequentially extends into the first sliding component and the first interlayer. The screwdriver head is placed in the first groove to anchor the dynamic pedicle screw on the spine.

[0012] Furthermore, the first sliding member includes a first sliding shell, a first limiting hole and a second limiting hole; the first limiting hole and the second limiting hole are respectively arranged at the centers of both ends of the first sliding shell at both ends of the first accommodating cavity, and are coaxial with the first joint member.

[0013] Furthermore, the first interlayer includes a second sliding shell and a limiting ring; the second sliding shell is placed in the first accommodating cavity; a third limiting hole communicating with the first limiting hole is provided at the center of one end of the second sliding shell, and the limiting ring is fixed at the center of the other end of the second sliding shell and placed in the second limiting hole; the inner cavity of the second sliding shell and the central cavity of the limiting ring constitute the second accommodating cavity, and the first joint head is placed in the second accommodating cavity.

[0014] Furthermore, one end surface of the cover plate is a joint surface for connecting with the first sliding shell, and the other end surface is a contact surface; a fourth limiting hole is provided in the center of the cover plate.

[0015] Furthermore, a fifth limiting hole coaxial with the first joint component is provided at the center of the end surface of the third joint component, and the fixing plate is connected to the extension plate through a second groove.

[0016] Furthermore, the thread of the first joint component includes a coarse thread and a fine thread, the thread depth and pitch of the coarse thread are greater than the thread depth and pitch of the fine thread; the fine thread and the coarse thread are sequentially arranged at the end of the stud away from the first joint head.

[0017] Furthermore, the first joint head is a spherical structure or a disc-shaped structure.

[0018] Furthermore, the dynamic stabilization structure also includes a dynamic rod, and the dynamic pedicle screw also includes a fourth joint component, a sixth limiting hole is provided in the center of the fourth joint component, and the fourth joint component is threaded into the fixing groove to press one end of the dynamic rod onto the cover plate; a plurality of the dynamic pedicle screws fix the dynamic rod on the spine.

[0019] Further, the dynamic rod comprises a second joint head, a joint cavity, a second interlayer, a fixing ring, a connecting block and a connecting shaft;

[0020] The second joint head comprises a joint head head and a connecting rod, the joint head head is fixed to one end of the connecting rod, and the two connecting blocks are symmetrically fixed to both sides of the connecting rod;

[0021] The joint cavity comprises an acetabular cup and a connecting rod, wherein the acetabular cup is fixed at one end of the connecting rod; the joint head is installed in the acetabular cup, and the joint head can rotate at a predetermined bending angle in the acetabular cup; the connecting rod has a through slot, and the connecting shaft is fixed in the through slot;

[0022] The second interlayer and the fixing ring are sequentially sleeved on the connecting rod, and the fixing ring is fixedly installed in the acetabulum to press the second interlayer on the joint head; a plurality of micro holes are evenly distributed around the fixing ring.

[0023] The present invention also discloses a dynamic pedicle screw of a dynamic stabilizing structure for spinal surgery, wherein the dynamic pedicle screw passes through the pedicle and is anchored on a corresponding vertebral body, and the dynamic pedicle screw comprises a first joint component, a second joint component and a third joint component;

[0024] The first joint component includes a stud, a thread and a first joint head; the thread is arranged on the stud, the first joint head is sleeved on one end of the stud, and the stud is provided with a first groove for accommodating a screwdriver head of a screwdriver;

[0025] The second joint component comprises a first sliding component, a first interlayer and a cover plate; the first interlayer is placed in a first accommodating cavity in the first sliding component, the first interlayer has a second accommodating cavity, and the first joint head is placed in the second accommodating cavity; the cover plate is placed on an end of the first sliding component away from the thread of the stud;

[0026] The third joint component includes a second sliding component and a fixing plate. The second sliding component has an end face at one end. The second sliding component includes a third accommodating cavity on one side of the end face. The second joint component is placed in the third accommodating cavity. The two fixing plates are symmetrically arranged at the other end of the second sliding component. A fixing groove is formed between the two fixing plates. The screwdriver is inserted into the fixing groove, passes through the cover plate and sequentially extends into the first sliding component and the first interlayer. The screwdriver head is placed in the first groove to anchor the dynamic pedicle screw on the spine.

[0027] Beneficial effects of the present invention:

[0028] The present invention can retain the range of motion of the spinal fixed segment, and is helpful to install the dynamic rod bent according to different spinal curvatures into the fixing groove from different angles. The installation operation of the dynamic pedicle screw in the present invention is similar to that of the traditional pedicle screw rod system, and is easy to use. It can be applied to cervical, thoracic, lumbar surgery, long segment spinal surgery and various spinal surgery simulation training. The present invention can reduce the phenomenon of stress concentration inside the dynamic stable structure, and reduce the incidence of internal fixation related complications such as internal fixation fracture and internal fixation displacement. After the dynamic pedicle screw is assembled with the dynamic rod, the surgical segment spine still retains the original range of motion, which can effectively improve the biomechanical properties of the spine after surgery and reduce the incidence of adjacent segment degeneration. When the dynamic pedicle screw is assembled with the orthopedic dynamic rod to treat spinal deformity, a continuous orthopedic force can be generated, and the orthopedic force loss caused by the deformation of the dynamic rod can be reduced. When the dynamic pedicle screw is screwed into the vertebral body through the pedicle, a pressurized and pulled effect can be generated between the thread and the cancellous bone in the vertebral body, which can improve the holding force of the screw. The screw tip arranged at the end of the dynamic pedicle screw can generate greater resistance when screwed into the vertebral body and contacts the bone cortex, thereby preventing the screw from penetrating the bone cortex and damaging the soft tissue around the vertebral body.

[0029] The first joint head of the first joint component of the present invention is placed in the second accommodating cavity, and a gap is left between the stud and the first limiting hole and the third limiting hole of the second joint component, so that the first joint component and the second joint component can generate a flexion and extension range of -5 to +5° and an axial rotation range of 360° and an axial movement, which can prevent stress from being concentrated at the junction of the stud and the first joint head during spinal movement, avoid fatigue fracture, and ensure the continuous stress of the dynamic pedicle screw. In addition, in spinal orthopedic surgery, the elastic activity between the first joint component and the second joint component can generate continuous orthopedic force, reducing the loss of orthopedic force caused by the deformation of the dynamic rod after the orthopedic dynamic rod is inserted into the tail end of the pedicle screw.

[0030] In addition, the micropores provided on the fixing ring of the dynamic rod allow tissue fluid to penetrate into the interior of the dynamic rod along the micropore channels, thereby lubricating contact positions such as the second joint head, the joint cavity, the buffer pad and the second interlayer, making the rotation of the dynamic stable structure smoother. After a long time, a fibrous connective tissue wrapping will be formed around the dynamic stable structure, which can form a regenerated joint capsule to improve the biomechanical properties. The fibrotic film produced by the structure surrounding the tissue fluid also provides biological stability for the dynamic stable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A three-dimensional schematic diagram of the dynamic stabilization structure of the present invention for spinal surgery Figure 1 ;

[0032] Figure 2 A three-dimensional schematic diagram of the dynamic stabilization structure of the present invention for spinal surgery Figure 2 ;

[0033] Figure 3 It is a cross-sectional schematic diagram of the dynamic stabilization structure used for spinal surgery of the present invention;

[0034] Figure 4 is a schematic diagram of a first joint component in the present invention;

[0035] Figure 5 A three-dimensional diagram of the second joint component in the present invention Figure 1 ;

[0036] Figure 6 A three-dimensional diagram of the second joint component in the present invention Figure 2 ;

[0037] Figure 7 A three-dimensional schematic diagram of the sliding member in the present invention Figure 1 ;

[0038] Figure 8 A three-dimensional schematic diagram of the sliding member in the present invention Figure 2 ;

[0039] Fig. 9 A three-dimensional diagram of the first interlayer in the present invention Figure 1 ;

[0040] Fig.10 A three-dimensional diagram of the first interlayer in the present invention Figure 2 ;

[0041] Fig.11 A three-dimensional schematic diagram of the cover plate in the present invention Figure 1 ;

[0042] Fig.12 A three-dimensional schematic diagram of the cover plate in the present invention Figure 2 ;

[0043] Fig.13 A three-dimensional schematic diagram of the third joint component in the present invention Figure 1 ;

[0044] Fig.14 A three-dimensional schematic diagram of the third joint component in the present invention Figure 2 ;

[0045] Fig.15 is a three-dimensional schematic diagram of the fourth joint component in the present invention;

[0046] Fig.16 It is a schematic diagram of a dynamic stable structure internal fixation of the spine used in spinal surgery according to the present invention;

[0047] Fig.17 A schematic diagram of retaining the range of motion of the nail tip in the dynamic stabilization structure used in spinal surgery of the present invention;

[0048] Fig.18 It is an axial cross-sectional view of the dynamic stabilization structure used for spinal surgery of the present invention;

[0049] Fig.19 It is a schematic diagram of the second joint head in the present invention;

[0050] Fig. 20 It is a schematic diagram of the joint cavity in the present invention;

[0051] Fig.21 It is a schematic diagram of the buffer pad in the present invention;

[0052] Fig. 22 It is a schematic diagram of the second interlayer in the present invention;

[0053] Fig.23 It is a schematic diagram of the fixing ring in the present invention;

[0054] Fig.24 It is a schematic diagram of the connection block in the present invention;

[0055] Fig.25 It is a schematic diagram of the connecting shaft in the present invention.

[0056] Wherein: 1-first joint part, 11-stud, 12-coarse thread, 13-fine thread, 14-first joint head, 15-first groove, 16-nail tip, 2-second joint part, 21-first sliding part, 211-first sliding shell, 212-first limiting hole, 213-first accommodating cavity, 214-second limiting hole, 22-first interlayer, 221-second sliding shell, 222-limiting ring, 223-second accommodating cavity, 224-third limiting hole, 23-cover plate, 231-joint surface, 232-fourth limiting hole, 233-contact surface, 3-third joint part, 31-second sliding part, 32-fifth limiting hole, 33-third accommodating cavity, 34-fixing plate, 35-extension plate, 36-second groove, 37-internal thread, 4-fourth joint part, 41-external thread, 42-sixth limiting hole, 5- The second joint head, 51-joint head, 52-connecting rod, 53-protrusion, 54-first nail channel, 55-connecting block contact surface, 6-joint cavity, 61-acetabular cup, 62-joint surface, 63-interlayer fixing groove, 64-interlayer contact surface, 65-inner thread, 66-connecting rod, 67-through groove, 68-connecting shaft contact surface, 69-second nail channel, 7-buffer pad, 71-joint cavity joint surface, 72-joint head joint surface, 8-second interlayer, 81-body, 82-neck, 83-fixing block, 84-joint cavity contact surface, 85-joint head contact surface, 86-connecting rod contact surface, 9-fixing ring, 91-through hole, 92-external thread, 93-micropore, 10-connecting block, 101-third nail channel, 102-protrusion contact surface, 17-connecting shaft, 171-fourth nail channel, 172-through groove contact surface. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the technical solution of the present application, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0058] The terms such as up, down, left, right, front and back in this application document are based on the positional relationships shown in the drawings. If the drawings are different, the corresponding positional relationships may also change accordingly, so they cannot be understood as limiting the scope of protection.

[0059] In the present invention, the terms "install", "connected", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection or mutual communication, a direct connection or an indirect connection through an intermediate medium, the internal connection of two components, or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] Embodiment 1

[0061] This embodiment describes a dynamic stabilization structure for spinal surgery, which is composed of a dynamic pedicle screw and a dynamic rod.

[0062] like Figure 1 and Figure 2 As shown, the dynamic pedicle screw comprises a first joint component 1, a second joint component 2, a third joint component 3 and a fourth joint component 4. The dynamic pedicle screw is made of a metal material or a polymer material, such as a titanium alloy, a cobalt-chromium alloy, or medical stainless steel. The first joint component 1 is connected to the third joint component 3 through the second joint component 2, the fourth joint component 4 is located in the third joint component 3, and the first joint component 1, the second joint component 2, the third joint component 3 and the fourth joint component 4 are coaxially arranged (such as Figure 3 shown).

[0063] Specifically, Figure 4 As shown, the first joint part 1 includes a screw 11, a coarse thread 12, a fine thread 13, a first joint head 14, a first groove 15 and a nail tip 16, and each part is coaxially arranged. Fine threads 13 and coarse threads 12 are arranged in sequence at the front end of the screw 11. The coarse thread 12 can be screwed into the vertebral body and engage with the cancellous bone in the vertebral body. The fine thread 13 can be screwed into the pedicle and engage with the cancellous bone in the pedicle. The thread depth and spacing of the front coarse thread 12 are greater than the rear fine thread 13. When the dynamic pedicle screw is screwed into the vertebral body through the pedicle, a pressurized lifting effect can be generated between the coarse thread 12 and the fine thread 13 and the cancellous bone in the vertebral body, which can improve the holding force of the dynamic pedicle screw. The nail tip 16 is arranged at the end of the coarse thread 12, which can be spherical or conical, and can generate greater resistance when contacting the cortical bone when screwing into the vertebral body, so as to prevent penetrating the cortical bone and damaging the soft tissue around the vertebral body. The first joint head 14 is sleeved and fixed on the rear end of the stud 11. The first joint head 14 is a spherical structure or a disc-shaped structure, and is used to connect with the second joint part 2. The first groove 15 is provided at the end of the stud 11 at the end of the first joint head 14, and is used to accommodate a screwdriver head, so as to tighten the stud 11. It can be a hexagonal groove, a cross groove, or the like that is convenient for matching with a screwdriver head.

[0064] The second joint 2 Figure 5 and Figure 6 As shown, it comprises a first sliding member 21, a first interlayer 22 and a cover plate 23. The cover plate 23 is installed at the rear end of the first sliding member 21, and the first interlayer 22 is placed in the inner cavity of the first sliding member 21 and the cover plate 23.

[0065] Among them, the first sliding member 21 is as follows Figure 7 and Figure 8The first sliding shell 211, the first limiting hole 212 and the second limiting hole 214 are shown. The first sliding shell 211 is composed of a front arc structure and a rear arc structure that are relatively buckled together, and is placed in the cover plate 23 and the third accommodating cavity 33 of the third joint part 3. The first sliding shell 211 has a first accommodating cavity 213 inside, and the first limiting holes 212 and the second limiting holes 214 at the left and right ends of the first accommodating cavity 213 are respectively arranged at the center of the two ends of the first sliding shell 211, and are coaxial with the first joint part 1, the stud 11 extends into the first interlayer 22 through the first limiting hole 212, and the screwdriver extends into the first interlayer 22 through the second limiting hole 214.

[0066] The first interlayer 22 is an elastic interlayer, which can be made of elastic wear-resistant polymer material or elastic metal braided material, such as silicone resin, polyaryletherketone, polycarbonate urethane (PCU), such as Fig. 9 and Fig.10 As shown, the first interlayer 22 includes a second sliding shell 221 and a limiting ring 222 . The second sliding shell 221 is an arc-shaped structure and is placed in the first accommodating cavity 213 of the first sliding member 21. A third limiting hole 224 is provided at the center of one end of the second sliding shell 221, which is coaxial and communicated with the first limiting hole 212. The limiting ring 222 is fixed at the center of the other end of the second sliding shell 221 and is placed in the second limiting hole 214. The inner cavity of the second sliding shell 221 and the central cavity of the limiting ring 222 constitute the second accommodating cavity 223. The first joint head 14 is installed in the second accommodating cavity 223. At the same time, a gap is left between the stud 11 and the first limiting hole 212 and the third limiting hole 224, so that a flexion and extension range of -5 to +5° and an axial rotation range of 360° and axial movement can be generated between the first joint member 1 and the second joint member 2, thereby retaining the activity of the spinal fixed segment, and preventing stress from being concentrated at the junction of the stud 11 and the first joint head 14 during spinal movement, avoiding fatigue fracture, and ensuring the continuous stress of the dynamic pedicle screw.

[0067] like Fig.11 and Fig.12 As shown, the cover plate 23 is a cylindrical structure, the fourth limiting hole 232 is set at the center of the cover plate 23, and is coaxially arranged with the third limiting hole 224. One end surface of the cover plate 23 is a joint surface 231, which is used to connect with the first sliding shell 211, so that the first sliding member 21 and the cover plate 23 can slide relative to each other. Axial pressure on the cover plate 23 can limit the movement of the first sliding member 21 and fix it. The other end surface of the cover plate 23 is a contact surface 233, which is used to connect with the dynamic rod.

[0068] The third joint part 3 Fig.13 and Fig.14As shown, it includes a second sliding member 31, a fifth limiting hole 32, a third accommodating cavity 33, a fixing plate 34, an extension plate 35, a second groove 36 and an internal thread 37. The second sliding member 31 has an end face at one end of the lower part, which can be a plane or an arc surface. The fifth limiting hole 32 is arranged at the center of the end face and is coaxially arranged with the first joint member 1. The third accommodating cavity 33 is placed inside the second sliding member 31 on the inner side of the end face of the second sliding member 31. The stud 11 of the first joint member 1 passes through the fifth limiting hole 32, and the first sliding member 21 and the cover plate 23 of the second joint member 2 are placed in the third accommodating cavity 33, so that the first joint member 1 and the second joint member 2 can produce axial movement, rotation and flexion and extension relative to each other when fixed. For example, the third joint member 3 has a flexion and extension range of -45° to +45° and an axial rotation range of 360°, which helps to install the dynamic rod bent according to different spinal curvatures into the fixing groove of the third joint member 3 from different angles, so that the dynamic stable structure can be applied to long segment spinal surgery. The upper part of the second sliding member 31 is a cylindrical structure, on which a fixing piece 34 is symmetrically arranged. The fixing piece 34 is a semi-arc structure, and the outer side is flush with the second sliding member 31. The inner side of the fixing piece 34 is an arc groove, and two arc grooves form a fixing groove for accommodating the dynamic rod. The tops of the two fixing pieces 34 are respectively connected to the extension piece 35 through the second groove 36. The second groove 36 is a semi-annular structure. After the dynamic rod is placed in the fixing groove, the extension pieces 35 on both sides are broken off from the second groove 36. The extension piece 35 of this embodiment is an extension of the fixing piece 34, which is helpful for installing the dynamic rod and screwing into the fourth joint part 4. The internal thread 37 is arranged on the inner surface of the fixing piece 34, the extension piece 35 and the second groove 36, and is used for threaded connection with the fourth joint part 4. The first groove 15, the first limiting hole 212, the second limiting hole 214, the third limiting hole 224 and the fifth limiting hole 32 in the dynamic pedicle screw of this embodiment are coaxial, which helps to prevent rotational displacement inside the screw assembly when using a screwdriver to screw the dynamic stabilization structure into the vertebral body.

[0069] The fourth joint 4 is as follows Fig.15 The columnar structure is shown, and its outer side is provided with an external thread 41 for threaded connection with the internal thread 37 of the third joint part 3. The center of the fourth joint part 4 has a sixth limiting hole 42 that penetrates the fourth joint part 4. The sixth limiting hole 42 is a polygonal structure, which is convenient for fixing the screwdriver. The fourth joint part 4 is screwed into the fixing groove, and the dynamic rod inserted into the fixing groove of the third joint part 3 is pressurized. The pressure is transmitted to the cover plate 23 for axial pressure, thereby fixing the spatial position of the second joint part 2 and the third joint part 3. The second joint part 2 can generate relative movement between the first joint part 1 and the second joint part 2 through the first interlayer 22. This design can reduce the phenomenon of internal stress concentration of the dynamic pedicle screw and reduce the incidence of internal fixation-related complications such as internal fixation fracture and internal fixation displacement.

[0070] After the dynamic pedicle screw is matched with the dynamic rod, the screwdriver passes through the sixth limiting hole 42, the fourth limiting hole 232 and the limiting ring 222 in sequence, and is fixed in the first groove 15, and the dynamic pedicle screw is passed through the pedicle to fix the vertebral body, which can be a real human spine or a simulated spine, etc. Fig.16 As shown, the fourth joint component 4 is then tightened downward along the fixing groove by a screwdriver, and the dynamic rod is pressed onto the cover plate 23, thereby stabilizing the spinal structure. Since the first joint head 14 and one end of the stud 11 of the first joint component 1 are placed in the second accommodating cavity 223, when the dynamic rod presses the cover plate 23, the first joint component 1 still has mobility, as shown in FIG. Fig.17 As shown, the nail tip 16 has a greater range of motion, which enables the fixed spinal segment to still maintain a partial range of motion and maintain a good curvature of the spine. The dynamic stabilization structure can adapt to the fixation of the cervical, thoracic and lumbar segments of the spine by changing the size of the structure.

[0071] Embodiment 2

[0072] The dynamic rod used in the above embodiment is as follows Fig.18 As shown, it includes a second joint head 5, a joint cavity 6, a buffer pad 7, a second interlayer 8, a fixing ring 9, a connecting block 10, and a connecting shaft 17.

[0073] The second joint head 5 Fig.19 The figure shows that it is composed of a circular joint head 51 and a connecting rod 52, wherein the connecting rod 52 is formed by integrating a cylindrical portion and a rectangular portion, and the joint head 51 is connected to the rectangular portion through the cylindrical portion, wherein a group of opposite side surfaces of the rectangular portion are symmetrically provided with arc-shaped protrusions 53, and the maximum dimension between the two protrusions 53 is the diameter of the cylindrical portion, and two connecting blocks 10 are symmetrically arranged on another group of opposite side surfaces of the rectangular portion, and the connecting surface with the connecting block 10 is a connecting block contact surface 55, and a plurality of first nail channels 54 are evenly distributed on the side where the connecting block contact surface 55 is located, which are used to cooperate with the fixing nails to lock the connecting block 10, and the connecting block 10 and the connecting rod 52 are combined into a cylindrical structure, and the combined cylindrical structure is fixed to the corresponding vertebra by a dynamic pedicle screw.

[0074] Joint cavity 6 Fig. 20The mortar cup 61 and the connecting rod 66 are shown. The mortar cup 61 is a hollow cylindrical structure, and one end of the mortar cup 61 is provided with a joint surface 62. The mortar cup 61 is connected to the connecting rod 66 through the joint surface 62. An internal thread 65 is provided at the other end of the mortar cup 61. A plurality of interlayer fixing grooves 63 are evenly distributed around the inner side of the side wall of the mortar cup 61 between the joint surface 62 and the internal thread 65. There is an interlayer contact surface 64 between adjacent interlayer fixing grooves 63. The interlayer fixing grooves 63 and the interlayer contact surface 64 match the second interlayer 8. The connecting rod 66 is a cylindrical structure as a whole, which is composed of a solid cylindrical part and a hollow connecting part. The mortar cup 61 is connected to the connecting part through the cylindrical part. The hollow part of the connecting part is a through groove 67 with an opening at the end arranged along the axial direction. The opposite sides of the two side walls of the connecting part on both sides of the through groove 67 are connecting shaft contact surfaces 68. When the connecting shaft 17 is placed in the through groove 67, the connecting rod 66 is connected to the connecting shaft 17. A plurality of second nail channels 69 are symmetrically distributed on both side walls of the connection part, and are used to cooperate with the fixing nails to lock the connection shaft 17. After the connection rod 66 is locked with the connection shaft 17, it is fixed to the corresponding vertebral body through the dynamic pedicle screw.

[0075] One end of the joint head 51 of the second joint head 5 is embedded in the acetabulum 61 of the joint cavity 6, and a gap is left between the two. The buffer pad 7 is filled in the gap. The joint head 51 of the second joint head 5 can rotate a predetermined bending angle in the acetabulum 61 to adapt to the changes in different spinal curvatures and ensure the mobility of the spine after spinal surgery. The buffer pad 7 is made of a polymer material with a high elastic modulus and wear resistance. While supporting the second joint head 5, it realizes a buffering function during the activity of the second joint head 5 and the joint cavity 6.

[0076] Buffer pad 7 Fig.21 The structure shown is bowl-shaped, with its outer side being the joint cavity joint surface 71 and the inner side being the joint head joint surface 72 . After installation, the joint cavity joint surface 71 is connected to the joint surface 62 , and the joint head joint surface 72 is connected to the joint head 51 .

[0077] The second interlayer 8 is placed on the second joint head 5 in the joint cavity 6. Fig. 22As shown, the second interlayer 8 includes a body 81, a neck 82, and a fixing block 83. The neck 82 is coaxially arranged at the end of the body 81, and a plurality of arc-shaped fixing blocks 83 are evenly distributed around the outside of the body 81, and cooperate with the interlayer fixing groove 63 of the joint cavity 6, which helps to maintain the stability of the internal structure of the dynamic stabilization system. Between adjacent fixing blocks 83 is a joint cavity contact surface 84, and the inner side of the body 81 is a joint head contact surface 85, which is an arc surface structure, used to contact the joint head 51 of the second joint head 5, and the inner side of the neck 82 is a connecting rod contact surface 86. After the second joint head 5 is connected to the joint cavity 6, the neck 82 is sleeved on the connecting rod 52, and a gap is left between the connecting rod contact surface 86 and the connecting rod 52 to provide a movable space for the second joint head 5. After the dynamic stabilization system is assembled, the upper part of the second interlayer 8 is located between the second joint head 5 and the fixing ring 9, which can reduce the stress concentration phenomenon between the connecting rod 52 and the fixing ring 9 and reduce the friction between the connecting rod 52 and the fixing ring 9 during the activity of the dynamic stabilization system.

[0078] The fixing ring 9 is threadedly connected with the acetabulum 61 in the joint cavity 6 to lock the second interlayer 8. The fixing ring 9 is a circular ring structure such as Fig.23 As shown, it includes a through hole 91, an external thread 92, and a micro hole 93. The through hole 91 is placed at the center of the fixing ring 9 for contacting the neck 82 of the second interlayer 8. The external thread 92 is arranged on the side wall of the fixing ring 9 for engaging with the internal thread 65, so that the second interlayer 8 is fixed inside the acetabulum 61 of the joint cavity 6. The fixing ring 9 is installed in the acetabulum 61 by means of threads, and it is convenient to disassemble and assemble. A plurality of micro holes 93 are arranged on the outer edge of the fixing ring 9. The micro holes 93 are through holes, which are helpful for fixing the equipment tools. At the same time, after the operation, the tissue fluid produced by the patient's body can penetrate into the inside of the dynamic stabilization system along the micro hole 93 channel, and play a lubricating role on the contact positions such as the second joint head 5, the joint cavity 6, the buffer pad 7 and the second interlayer 8, so that the rotation of the dynamic stabilization system is smoother. After a long time, a fibrous connective tissue wrapping will be formed around the dynamic stabilization structure, which can form a regenerated joint capsule to improve the biomechanical properties. The fibrotic film produced by the structure around the tissue fluid also provides biological stability for the dynamic stabilization structure.

[0079] Connecting block 10 as Fig.24 The columnar structure with an arcuate cross section is shown, which is composed of a straight surface and an arcuate surface, and has the same structure as the side wall of the connecting portion of the connecting rod 66, and the diameter of the arcuate surface is the same as the diameter of the connecting rod 52. The straight surface is a convex contact surface 102. When the two connecting blocks 10 are symmetrically installed on the second joint head 5, the convex contact surface 102 is connected to the connecting block contact surface 55, and the connecting block 10 and the connecting rod 52 form a cylindrical structure. A plurality of third nail channels 101 corresponding to the first nail channels 54 are evenly distributed on the connecting block 10, and the fixing nails anchor the connecting block 10 on the rectangular parallelepiped portion of the connecting rod 52 through the third nail channels 101 and the first nail channels 54.

[0080] Connecting shaft 17 Fig.25 As shown, its structure is the same as the rectangular parallelepiped portion of the second joint head 5, and a group of opposite side surfaces of the connecting shaft 17 are through-groove contact surfaces 172, which match the connecting shaft contact surface 68. A plurality of fourth nail channels 171 corresponding to the first nail channels 54 are provided on the side where the through-groove contact surface 172 is located, and the fixing nails pass through the second nail channels 69 and the fourth nail channels 171 to anchor the joint cavity 6 and the connecting shaft 17.

[0081] In the simulation training of cervical, thoracic, lumbar or spinal surgery, the dynamic rod of this embodiment is used in conjunction with the dynamic pedicle screw: when a single dynamic rod is used, the two connecting blocks 10 are symmetrically anchored on both sides of the rectangular body of the connecting rod 52, and the connecting shaft 17 is anchored in the through groove 67 of the connecting rod 66. The two ends of the dynamic rod are respectively extended into the tail wing fixing groove of the dynamic pedicle screw on the same side, and the fourth joint part 4 is screwed into the fixing groove to fix the dynamic rod, and the dynamic pedicle screw passes through the pedicle and is fixed on the corresponding vertebral body. When multiple dynamic rods are used for assembly, the rectangular body of a connecting rod 52 is fixed in the through groove 67 of the adjacent dynamic rod. After the multiple dynamic rods are spliced ​​into a multi-link structure, one end of the through groove 67 is provided, and the connecting shaft 17 is fixed in the through groove 67, and one end of the connecting rod 52 is provided, and the two connecting blocks 10 are symmetrically fixed on both sides of the rectangular body. The multi-link structure is bent according to the actual situation of the curvature of the multi-segment vertebra. The two ends of the dynamic rod pass through the fixing grooves of the tail wings of the dynamic pedicle screws at the same level on the same side. The fourth joint part 4 is screwed into the fixing groove to fix the dynamic rod. The dynamic pedicle screws pass through the pedicles and are fixed on the corresponding vertebra.

[0082] The second joint head 5 of the dynamic rod can rotate within the joint cavity 6 to a predetermined bending angle to adapt to the changes in different spinal curvatures. When used in combination with the dynamic pedicle screw, the mobility of the spine can be further ensured.

[0083] Although the principles of the present invention are described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above embodiments are merely explanations of the exemplary implementations of the present invention, and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute limitations on the scope of the present invention, and any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, fall within the protection scope of the present invention.

Claims

1. A dynamic stabilization structure for spinal surgery, characterized in that: The dynamic stabilization structure comprises a dynamic pedicle screw, and the dynamic pedicle screw comprises a first joint component (1), a second joint component (2) and a third joint component (3); The first joint component (1) comprises a stud (11), a thread and a first joint head (14); the thread is arranged on the stud (11), the first joint head (14) is sleeved on one end of the stud (11), and the stud (11) is provided with a first groove (15) for accommodating a screwdriver head of a screwdriver; The second joint component (2) comprises a first sliding component (21), a first interlayer (22) and a cover plate (23); the first sliding component (21) comprises a first sliding shell (211), a first limiting hole (212) and a second limiting hole (214); the first sliding shell (211) comprises a front arc structure and a rear arc structure which are relatively buckled together; the first sliding shell (211) has a first accommodating cavity (213), and the first limiting hole (212) and the second limiting hole (214) are respectively arranged at the centers of both ends of the first sliding shell (211), and are coaxial with the first joint component (1); the first interlayer (22) is placed in the first accommodating cavity (213) and is an elastic interlayer; the first interlayer (22) comprises a second sliding shell (221) and a limiting ring (22 2); the second sliding shell (221) is an arc-shaped structure; a third limiting hole (224) coaxial with and communicating with the first limiting hole (212) is provided at the center of one end of the second sliding shell (221); the limiting ring (222) is fixed at the center of the other end of the second sliding shell (221) and is placed in the second limiting hole (214); the inner cavity of the second sliding shell (221) and the central cavity of the limiting ring (222) form a second accommodating cavity (223); the first joint head (14) is placed in the second accommodating cavity (223); a gap is left between the stud (11) and the first limiting hole (212) and the third limiting hole (224); the cover plate (23) is placed on the end of the first sliding member (21) away from the thread of the stud (11); The third joint component (3) comprises a second sliding component (31) and a fixing plate (34); one end of the second sliding component (31) comprises an end surface; the second sliding component (31) comprises a third accommodating cavity (33) on one side of the end surface; the second joint component (2) is placed in the third accommodating cavity (33); two fixing plates (34) are symmetrically arranged at the other end of the second sliding component (31); a fixing groove is formed between the two fixing plates (34); the screwdriver is inserted into the fixing groove, passes through the cover plate (23), and sequentially extends into the first sliding component (21) and the first interlayer (22); the screwdriver head is placed in the first groove (15), and the dynamic pedicle screw is anchored on the spine.

2. The dynamic stabilization structure for spinal surgery according to claim 1, characterized in that: One end surface of the cover plate (23) is a joint surface (231) for connecting with the first sliding shell (211), and the other end surface is a contact surface (233); a fourth limiting hole (232) is provided at the center of the cover plate (23).

3. The dynamic stabilization structure for spinal surgery according to claim 1, characterized in that: A fifth limiting hole (32) coaxial with the first joint component (1) is provided at the center of the end surface of the third joint component (3), and the fixing plate (34) is connected to the extension plate (35) via a second groove (36).

4. The dynamic stabilization structure for spinal surgery according to claim 1, characterized in that: The thread of the first joint component (1) comprises a coarse thread (12) and a fine thread (13); the thread depth and pitch of the coarse thread (12) are greater than the thread depth and pitch of the fine thread (13); and the fine thread (13) and the coarse thread (12) are sequentially arranged at an end of the stud (11) away from the first joint head (14).

5. The dynamic stabilization structure for spinal surgery according to claim 1, characterized in that: The first joint head (14) is a spherical structure or a disc-shaped structure.

6. The dynamic stabilization structure for spinal surgery according to claim 1, characterized in that: The dynamic stabilization structure also includes a dynamic rod, and the dynamic pedicle screw also includes a fourth joint component (4). A sixth limiting hole (42) is provided at the center of the fourth joint component (4). The fourth joint component (4) is screwed into the fixing groove to press one end of the dynamic rod onto the cover plate (23); a plurality of the dynamic pedicle screws fix the dynamic rod on the spine.

7. The dynamic stabilization structure for spinal surgery according to claim 6, characterized in that: The dynamic rod comprises a second joint head (5), a joint cavity (6), a second interlayer (8), a fixing ring (9), a connecting block (10) and a connecting shaft (17); The second joint head (5) comprises a joint head portion (51) and a connecting rod (52), the joint head portion (51) being fixed to one end of the connecting rod (52), and the two connecting blocks (10) being symmetrically fixed to both sides of the connecting rod (52); The joint cavity (6) comprises an acetabular cup (61) and a connecting rod (66), wherein the acetabular cup (61) is fixed to one end of the connecting rod (66); the joint head portion (51) is installed in the acetabular cup (61), and the joint head portion (51) can rotate within the acetabular cup (61) to a predetermined bending angle; the connecting rod (66) has a through groove (67), and the connecting shaft (17) is fixed in the through groove (67); The second interlayer (8) and the fixing ring (9) are sequentially sleeved on the connecting rod (52); the fixing ring (9) is fixedly installed in the acetabulum (61) to press the second interlayer (8) onto the joint head (51); and a plurality of micropores (93) are evenly distributed around the fixing ring (9).

8. A dynamic pedicle screw for a dynamic stabilization structure for spinal surgery, characterized in that: The dynamic pedicle screw passes through the pedicle and is anchored on the corresponding vertebral body, and the dynamic pedicle screw comprises a first joint component (1), a second joint component (2) and a third joint component (3); The first joint component (1) comprises a stud (11), a thread and a first joint head (14); the thread is arranged on the stud (11), the first joint head (14) is sleeved on one end of the stud (11), and the stud (11) is provided with a first groove (15) for accommodating a screwdriver head of a screwdriver; The second joint component (2) comprises a first sliding component (21), a first interlayer (22) and a cover plate (23); the first sliding component (21) comprises a first sliding shell (211), a first limiting hole (212) and a second limiting hole (214); the first sliding shell (211) is composed of a front arc structure and a rear arc structure that are relatively buckled together; the first sliding shell (211) has a first accommodating cavity (213), and the first limiting hole (212) and the second limiting hole (214) are respectively arranged at the centers of both ends of the first sliding shell (211), and are coaxial with the first joint component (1); the first interlayer (22) is placed in the first accommodating cavity (213) and is an elastic interlayer; the first interlayer (22) comprises a second sliding shell (221) and a limiting ring (222); the second sliding The movable housing (221) is an arc-shaped structure and is placed in the first accommodating cavity (213); a third limiting hole (224) coaxial with and communicated with the first limiting hole (212) is provided at the center of one end of the second sliding housing (221); the limiting ring (222) is fixed at the center of the other end of the second sliding housing (221) and is placed in the second limiting hole (214); the inner cavity of the second sliding housing (221) and the central cavity of the limiting ring (222) form a second accommodating cavity (223); the first joint head (14) is placed in the second accommodating cavity (223); a gap is left between the stud (11) and the first limiting hole (212) and the third limiting hole (224); the cover plate (23) is placed on the end of the first sliding member (21) away from the thread of the stud (11); The third joint component (3) comprises a second sliding component (31) and a fixing plate (34); one end of the second sliding component (31) comprises an end surface; the second sliding component (31) comprises a third accommodating cavity (33) on one side of the end surface; the second joint component (2) is placed in the third accommodating cavity (33); two fixing plates (34) are symmetrically arranged at the other end of the second sliding component (31); a fixing groove is formed between the two fixing plates (34); the screwdriver is inserted into the fixing groove, passes through the cover plate (23), and sequentially extends into the first sliding component (21) and the first interlayer (22); the screwdriver head is placed in the first groove (15), and the dynamic pedicle screw is anchored on the spine.

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