A dynamic stabilization system for the spine

Abstract

The present invention relates to a dynamic stabilization system for spine, the dynamic stabilization system comprises a joint head, a joint cavity, a connecting block, a connecting shaft, and a fixing nail; the joint head comprises a joint head head and a connecting rod, the joint head head is fixed at one end of the connecting rod; two connecting blocks are symmetrically arranged on both sides of the connecting rod and fixed by the fixing nail; the joint cavity comprises an acetabulum and a connecting rod, the acetabulum is fixed at one end of the connecting rod; the joint head head is installed in the acetabulum, and the joint head head can rotate a predetermined bending angle in the acetabulum; the connecting rod has a through groove, the connecting shaft is placed in the through groove, and is fixed by the fixing nail; the dynamic stabilization system is fixed to the corresponding vertebral body of the spine by a pedicle screw. The present invention can be applied to the dynamic stabilization of the spine in cervical, thoracic and lumbar surgeries, and can not only adapt to the changes of different spinal curvatures, but also reduce the stress concentration phenomenon.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment, and in particular to a dynamic stabilization system for the spine. Background Art

[0002] The use of pedicle screw-rod fixation systems has become an important surgical intervention for spinal disorders. However, one of the most significant drawbacks of rigid fixation and fusion is the reduced range of motion of the fused segment. Furthermore, adjacent segment degeneration is another significant postoperative complication. Dynamic stabilization systems can serve as an alternative to rigid spinal fixation, helping to reduce the incidence of adjacent segment degeneration and maintain physiological spinal motion and function.

[0003] The Dynesys system is a dynamic stabilization system based on pedicle screws and elastic connecting components. 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 polycarbonate polyurethane flexible connecting rod can be implanted after preloading. The Dynesys system axial strip can generate greater tensile stress, enabling it to effectively resist flexion torque. From a biomechanical point of view, the Dynesys system reduces the overall range of motion of the spine, but compared with rigid internal fixation systems, the Dynesys system retains a certain degree of mobility.

[0004] During use, the Dynesys system needs to restore the biomechanical properties of the posterior annulus fibrosus and facet joints of the intervertebral disc. This requires rebuilding the natural balance of the posterior muscle structure and the intervertebral disc, making the surgical procedure complex. The structural design and material characteristics of the Dynesys system result in a significant increase in the stress of the adjacent segment intervertebral disc. In addition, the axial strips of the Dynesys system can generate greater tensile stress in the sagittal plane, while the tensile force in the transverse plane is significantly insufficient. Therefore, the Dynesys system cannot achieve ideal stabilization in all directions of movement. When the Dynesys system is used for long-segment stabilization of more than four vertebrae, it will cause increased stress on the pedicle screws, thereby increasing the incidence of pedicle screw loosening and fracture.

[0005] The K-ROD system is another dynamic stabilization system widely used in clinical practice. 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 have higher torsional stiffness than the polycarbonate polyurethane flexible connecting rods in the Dynesys system. 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 is because the polyaryletherketone connecting rods are stiffer than the polycarbonate polyurethane flexible connecting rods, and the K-ROD system absorbs most of the load acting on the posterior bony structure of the spine. Compared with the Dynesys system, the K-ROD system provides greater stiffness in extension, torsion, and lateral bending movements, which can provide good protection for the surgical area and adjacent segments of the spine.

[0006] The K-ROD system's internal titanium alloy cable structure cannot be effectively cut to the required length during use, increasing the difficulty of actual installation. The polyaryletherketone connector in the K-ROD system generates significant stiffness, which restricts the contact between the facet joints of the deployed segments, causing overcompensation of the facet joints of adjacent segments. This ultimately increases the load on the adjacent facet joints in all directions of motion and increases the risk of adjacent facet joint degeneration.

[0007] The Isobar TLL system is a semi-rigid stabilization system primarily consisting of universal pedicle screws and two dynamic connecting rods. The key moving component of the dynamic connecting rods is a unique shock-absorbing structure composed of stacked titanium rings. The range of motion of the shock-absorbing structure is similar to the physiological range of motion of the spine. Semi-rigid internal fixation devices rely primarily on the pedicle screws to absorb the loads generated by the fixed segment's motion in various directions and planes, thereby ensuring a certain range of motion at the fixed segment. The Isobar TTL dynamic stabilization system can separately fix the fused and non-fused segments of the spine, allowing for selective fusion of spinal segments. The Isobar TTL dynamic stabilization system has demonstrated excellent therapeutic effects in the treatment of bisegmental lumbar degenerative disease. This semi-rigid fixation system, based on pedicle screws, reduces intervertebral joint pressure, protects the intervertebral joints of the non-fused segments, absorbs stress generated by the fixed segments in various directions and planes of motion, distributes axial stress and shear forces during flexion and extension to the intervertebral discs, and stabilizes the lumbar spine while maintaining a certain degree of lumbar mobility. In addition, Isobar TTL can disperse the stress of adjacent segments, thereby reducing or delaying the occurrence of adjacent segment degeneration.

[0008] The unique shock-absorbing structure of the Isobar TTL dynamic stabilization system, comprised of stacked titanium rings, is subject to metal fatigue and wear during use, gradually reducing its ability to support the intervertebral disc and protect spinal mobility. The structural characteristics of the Isobar TTL make it difficult to use for long-segment surgeries involving more than four levels. Furthermore, the Isobar TTL's semi-rigid structure prevents it from being bent into the specific arc required during surgery, making installation difficult. Furthermore, none of the aforementioned dynamic stabilization systems are suitable for the treatment of cervical spine disorders. Summary of the Invention

[0009] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a dynamic stabilization system for the spine, which has a simple surgical operation process, reduces the risk of degeneration of adjacent segments, can be used for dynamic stabilization of the spine during cervical, thoracic and lumbar spine surgery, and can adapt to changes in different spinal curvatures after surgery.

[0010] The specific technical solutions of the present invention are as follows:

[0011] A dynamic stabilization system for the spine, comprising a joint head, a joint cavity, a connecting block, a connecting shaft, and a fixing nail;

[0012] The joint head comprises a joint head portion and a connecting rod, wherein the joint head portion is fixed to one end of the connecting rod; the two connecting blocks are symmetrically placed on both sides of the connecting rod and fixed by the fixing pins;

[0013] The joint cavity includes an acetabulum and a connecting rod, wherein the acetabulum is fixed to one end of the connecting rod; the joint head is installed in the acetabulum and can rotate to a predetermined bending angle in the acetabulum; the connecting rod has a through slot, and the connecting shaft is placed in the through slot and fixed by the fixing pin;

[0014] The dynamic stabilization system is fixed to the corresponding vertebral body of the spine via pedicle screws.

[0015] Furthermore, the dynamic stabilization system further includes a cushioning pad, a gap is left between the head of the joint head and the acetabulum, and the cushioning pad is filled in the gap.

[0016] Furthermore, the dynamic stabilization system further comprises an interlayer and a fixing ring; the interlayer and the fixing ring are sequentially sleeved on the joint head; the fixing ring is fixedly installed in the acetabulum to press the interlayer on the joint head.

[0017] Furthermore, the interlayer includes a body, a neck, and a fixing block, the neck is coaxially arranged at the end of the body, and multiple fixing blocks are evenly distributed around the outside of the body; the body is in contact with the head of the joint, and the neck is sleeved on the connecting rod; the fixing block is installed in multiple interlayer fixing grooves evenly distributed around the acetabulum.

[0018] Furthermore, the fixing ring includes a through hole, an external thread, and microholes; the fixing ring is sleeved on the body through the through hole, and the fixing ring is threadedly connected to the internal thread at one end of the acetabulum through the external thread; a plurality of microholes are evenly distributed around the fixing ring.

[0019] Furthermore, the connecting rod is composed of a cylindrical portion and a rectangular portion, the joint head is connected to the rectangular portion through the cylindrical portion, a group of opposite side surfaces of the rectangular portion are contact surfaces of the connecting block, and a plurality of first nail channels are evenly distributed on the side surfaces where the contact surfaces of the connecting block are located; a plurality of third nail channels corresponding to the first nail channels are evenly distributed on the connecting block, and the fixing nails pass through the third nail channels and are anchored to the first nail channels.

[0020] Furthermore, the acetabular cup is a hollow cylindrical structure, one end of the acetabular cup is provided with a joint surface, and the acetabular cup is connected to the connecting rod through the joint surface.

[0021] Furthermore, the connecting rod is composed of a cylindrical portion and a connecting portion, the acetabular cup is connected to the connecting portion through the cylindrical portion, and the through groove is arranged axially along the connecting portion; a plurality of second nail channels are symmetrically distributed on both side walls of the connecting portion, and a plurality of fourth nail channels corresponding to the second nail channels are provided on the connecting shaft, and the fixing nails are anchored through the second nail channels and the fourth nail channels.

[0022] The present invention further discloses a method for using the dynamic stabilization system for the spine according to any one of the above methods. In single-segment spinal surgery or simulation training of single-segment spinal surgery, the method for using the dynamic stabilization system comprises the following steps:

[0023] (1) Place the cushion pad in the acetabulum of the joint cavity, and then extend the head of the joint head into the cushion pad;

[0024] (2) The interlayer and the fixing ring are sequentially sleeved on the joint head, and the joint cavity, the cushion, the interlayer and the fixing ring are coaxially arranged. The body of the interlayer is connected to the head of the joint head, and the fixing block of the interlayer is placed in the fixing groove of the interlayer. The neck of the interlayer is sleeved on the connecting rod, and a gap is left between the neck and the connecting rod; the fixing ring is sleeved on the neck and is threadedly connected to the joint cavity;

[0025] (3) Two connecting blocks are symmetrically placed on both sides of the rectangular part of the connecting rod and anchored by fixing nails;

[0026] (4) The connecting shaft is placed in the through groove of the joint cavity and anchored by a fixing pin;

[0027] (5) Selecting pedicle screws corresponding to the spine to be fixed; on one side of the spine, two pedicle screws are respectively passed through the pedicles and fixed to the corresponding vertebral bodies; both ends of the dynamic stabilization system are respectively passed through the grooves of the tail wing of the pedicle screw on the same side and screwed into the tail wing through the nut for fixation, wherein the spine is a real human spine or a simulated spine;

[0028] The same approach was used to combine the dynamic stabilization system with the pedicle screw tail on the other side of the spine.

[0029] Furthermore, multiple dynamic stabilization systems are required to be used in multi-segment spinal surgery or simulation training of multi-segment spinal surgery, and the method of using the dynamic stabilization systems includes the following steps:

[0030] S1. The joint heads and joint cavities in multiple dynamic stabilization systems are connected in accordance with the steps and procedures in single-segment spinal surgery;

[0031] S2. placing the rectangular parallelepiped portion of the connecting rod of one dynamic stabilization system into the through slot of the adjacent dynamic stabilization system and anchoring it with fixing pins;

[0032] S3. After multiple dynamic stabilization systems are connected to form a multi-link structure, the multi-link structure has a through slot at one end, in which a connecting shaft is placed and anchored by a fixing pin; at the other end of the multi-link structure, two connecting blocks are symmetrically placed on both sides of the rectangular parallelepiped portion of the connecting rod and anchored by a fixing pin;

[0033] S4. Select pedicle screws corresponding to the spine to be fixed; on one side of the spine to be fixed, multiple pedicle screws are respectively passed through the pedicles and fixed to the corresponding vertebral bodies; the multi-link structure formed by the multiple dynamic stabilization systems is bent according to the actual curvature of the multi-segment vertebral bodies; the two ends of the dynamic stabilization system are respectively passed through the grooves on the tail of the pedicle screw at the same level on the same side, and screwed into the tail through the nut for fixation;

[0034] The same approach was used to combine the dynamic stabilization system with the pedicle screw tail on the other side of the spine.

[0035] Beneficial effects of the present invention:

[0036] The dynamic stabilization system of the present invention is a detachable artificial joint structure, which can be customized with components of different sizes according to the different segments to be fixed to adapt to the fixation of different segments of the spine. The present invention can be applied to the dynamic stabilization of the spine in cervical, thoracic and lumbar spine surgeries, and is not limited to lumbar spine surgery. The surgical operation process is simple, the risk of degeneration of adjacent segments is low, and because the joint head can be bent to a specific bending angle relative to the joint cavity, it can adapt to changes in different spinal curvatures.

[0037] The buffer pad between the joint head and the joint cavity, as well as the gap between the interlayer and the connecting rod of the joint head in the dynamic stabilization system of the present invention, can enable flexion and extension activities within a predetermined angle between the joint head and the joint cavity, realize longitudinal activities within a certain range, and ensure the mobility of the spine after spinal surgery.

[0038] In single-segment spinal surgery, the joint head and joint cavity are anchored to the connecting block and connecting shaft respectively through fixation screws, forming a complete columnar structure. In multi-segment spinal surgery, the connecting rod of the joint head and the through slot in the connecting rod of the joint cavity can be connected by fixation screws, thereby assembling and connecting multiple dynamic stabilization systems for dynamic spinal stabilization.

[0039] The upper portion of the interlayer in the present invention is positioned between the joint head's connecting rod and retaining ring, reducing stress concentration in these two areas and minimizing friction between them during movement of the dynamic stabilization system. The interlayer's retaining block integrates with the interlayer's retaining groove within the acetabulum, helping to maintain the stability of the dynamic stabilization system's internal structure.

[0040] The micropores of the retaining ring in this invention allow tissue fluid to penetrate into the dynamic stabilization system through these micropores, lubricating contact points such as the joint head, joint cavity, cushion, and interlayer, making the dynamic stabilization system's rotation smoother. Over time, fibrous connective tissue forms around the dynamic stabilization system, regenerating the joint capsule and improving biomechanical properties. The fibrotic film formed around the structure of the tissue fluid also provides biological stability for the dynamic stabilization system. Furthermore, the retaining ring is threadedly fixed to the acetabulum, making it easy to assemble and disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is an axial cross-sectional view of a dynamic stabilization system for the spine according to the present invention;

[0042] Figure 2 The axial appearance of the dynamic stabilization system for the spine of the present invention Figure 1 ;

[0043] Figure 3 The axial appearance of the dynamic stabilization system for the spine of the present invention Figure 2 ;

[0044] Figure 4 It is a left side view of the dynamic stabilization system for the spine of the present invention;

[0045] Figure 5 It is a right side view of the dynamic stabilization system for the spine according to the present invention;

[0046] Figure 6 Schematic diagram of the joint head in the present invention;

[0047] Figure 7 Schematic diagram of the joint cavity in the present invention;

[0048] Figure 8 Schematic diagram of the cushion in the present invention;

[0049] Figure 9 Schematic diagram of the interlayer in the present invention;

[0050] Figure 10 Schematic diagram of the fixing ring in the present invention;

[0051] Figure 11 Schematic diagram of the connection block in the present invention;

[0052] Figure 12 Schematic diagram of the connecting shaft in the present invention;

[0053] Figure 13 This is a schematic diagram of a fixing pin in the present invention;

[0054] Figure 14 This is a schematic diagram of the present invention in use during single-segment surgery;

[0055] Figure 15 Schematic diagram of the connection status of multiple dynamic stabilization systems of the present invention.

[0056] Among them: 1- joint head, 11- joint head head, 12- connecting rod, 13- protrusion, 14- first nail channel, 15- connecting block contact surface, 2- joint cavity, 21- acetabular cup, 22- joint surface, 23- sandwich fixation groove, 24- sandwich contact surface, 25- internal thread, 26- connecting rod, 27- through groove, 28- connecting shaft contact surface, 29- second nail channel, 3- cushion, 31- joint cavity joint surface, 32- joint head joint Nodal surface, 4-interlayer, 41-body, 42-neck, 43-fixing block, 44-articular cavity contact surface, 45-articular head contact surface, 46-connecting rod contact surface, 5-fixing ring, 51-through hole, 52-external thread, 53-micropore, 6-connecting block, 61-third nail channel, 62-convex contact surface, 7-connecting shaft, 71-fourth nail channel, 72-through groove contact surface, 8-fixing nail, 81-full thread, 82-groove. 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 "up", "down", "left", "right", "front", and "back" in this application are based on the positional relationships shown in the accompanying drawings. The corresponding positional relationships may vary depending on the drawings, and should not be construed as limiting the scope of protection.

[0059] In the present invention, the terms "installed," "connected," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, or mutual communication. They may be directly connected or indirectly connected through an intermediate medium. They may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] This embodiment describes a dynamic stabilization system for the spine, which can be combined with artificial intervertebral disc implantation technology to further reshape the stability of the three-joint complex structure between the spinal intervertebral disc and the posterior facet joint, thereby improving the biomechanical properties of the spine after surgery.

[0061] like Figures 1 to 5 As shown, the dynamic stabilization system includes a joint head 1, a joint cavity 2, a buffer pad 3, an interlayer 4, a fixing ring 5, a connecting block 6, a connecting shaft 7, and a fixing nail 8.

[0062] One end of the joint head 1 is embedded in the joint cavity 2 to form a connecting rod structure, and a gap is left between the two. The joint head 1 can rotate to a predetermined bending angle in the joint cavity 2 to adapt to the changes in different spinal curvatures. For example, the preset bending angle in this embodiment is 10°, so a flexion and extension range of motion within 10° can be generated between the joint head 1 and the joint cavity 2, ensuring the mobility of the spine after spinal surgery. The buffer pad 3 is filled in the gap. The buffer pad 3 is made of a polymer material with a high elastic modulus and wear resistance. While supporting the joint head 1, it realizes a buffering function when the joint head 1 and the joint cavity 2 move. Preferably, the gap width is not greater than 2mm, and the thickness of the buffer pad 3 matches the gap width, so that a longitudinal motion of less than 2mm is generated between the joint head 1 and the joint cavity 2. The interlayer 4 is put on the joint head 1 in the joint cavity 2 and locked with the joint cavity 2 by a fixing ring 5. The other end of the joint head 1 is anchored to the connecting block 6 by a fixing nail 8, and the other end of the joint cavity 2 is anchored to the connecting shaft 7 by a fixing nail 8.

[0063] Specifically, the joint head 1 is as Figure 6The joint head 11 is shown as a circular joint head and a connecting rod 12. The connecting rod 12 is formed by integrating a cylindrical portion and a rectangular parallelepiped portion. The joint head 11 is connected to the rectangular parallelepiped portion through the cylindrical portion. A set of opposite sides of the rectangular parallelepiped portion are symmetrically provided with arc-shaped protrusions 13. The maximum dimension between the two protrusions 13 is the diameter of the cylindrical portion. The other set of opposite sides of the rectangular parallelepiped portion is a connecting block contact surface 15 for connecting with the connecting block 6. A plurality of first nail tracks 14 are evenly distributed on the side where the connecting block contact surface 15 is located, for cooperating with the fixing nails 8 to lock the connecting block 6. The joint head 1 can be made of high-strength metal or polymer material.

[0064] Joint cavity 2 Figure 7 The mortar cup 21 is shown as a hollow cylindrical structure and has an articulating surface 22 at one end. The mortar cup 21 is connected to the connecting rod 26 via the articulating surface 22. An internal thread 25 is provided at the other end of the mortar cup 21. Between the articulating surface 22 and the internal thread 25, a plurality of interlayer fixing grooves 23 are evenly distributed around the inner side of the side wall of the mortar cup 21. Interlayer contact surfaces 24 are located between adjacent interlayer fixing grooves 23. The interlayer fixing grooves 23 and the interlayer contact surface 24 match the interlayer 4. The connecting rod 26 is an overall cylindrical structure consisting of a solid cylindrical portion and a hollow connecting portion. The acetabular cup 21 is connected to the connecting portion via the cylindrical portion. The hollow portion of the connecting portion is an axially disposed through-slot 27 with an open end. The opposing side surfaces of the connecting portion's two side walls on either side of the through-slot 27 serve as connecting shaft contact surfaces 28. When the connecting shaft 7 is inserted into the through-slot 27, the connecting shaft 7 engages with the connecting shaft 7. Multiple second nail tracks 29 are symmetrically distributed on the two side walls of the connecting portion for engaging with the fixing nails 8 to lock the connecting shaft 7. Furthermore, in this embodiment, the joint cavity 2 can be made of a high-strength metal or polymer material.

[0065] When the joint head 1 is connected to the joint cavity 2, the joint head head 11 of the joint head 1 is located in the acetabulum 21 of the joint cavity 2, and the cushion 3 is filled between the joint head head 11 and the acetabulum 21. Figure 8 The structure shown is bowl-shaped, with the outer side being the joint cavity articular surface 31 and the inner side being the joint head articular surface 32 . After installation, the joint cavity articular surface 31 is connected to the articular surface 22 , and the joint head articular surface 32 is connected to the joint head 11 .

[0066] Interlayer 4 Figure 9The figure shows a body 41, a neck 42, and a fixing block 43. The neck 42 is coaxially arranged at the end of the body 41. A plurality of arc-shaped fixing blocks 43 are evenly distributed around the outside of the body 41 and cooperate with the interlayer fixing groove 23 of the joint cavity 2 to help maintain the stability of the internal structure of the dynamic stabilization system. Between adjacent fixing blocks 43 is the joint cavity contact surface 44. The inner side of the body 41 is the joint head contact surface 45, which is an arc-shaped structure and is used to contact the joint head 11 of the joint head 1. The inner side of the neck 42 is the connecting rod contact surface 46. After the joint head 1 is connected to the joint cavity 2, the neck 42 is sleeved on the connecting rod 12. A gap is left between the connecting rod contact surface 46 and the connecting rod 12 to provide space for the joint head 1 to move. After the dynamic stabilization system is assembled, the upper part of the interlayer 4 is located between the joint head 1 and the fixing ring 5, which can reduce the stress concentration phenomenon between the connecting rod 12 and the fixing ring 5, and reduce the friction between the connecting rod 12 and the fixing ring 5 during the movement of the dynamic stabilization system. The material of the interlayer 4 is a wear-resistant polymer material, such as silicone resin, polyaryletherketone, or polycarbonate urethane (PCU).

[0067] The fixing ring 5 is a circular ring structure. Figure 10 The device shown includes a through hole 51, external threads 52, and micropores 53. The through hole 51 is located at the center of the fixing ring 5 and is used to contact the neck 42 of the interlayer 4. The external threads 52 are provided on the sidewalls of the fixing ring 5 and are used to engage with the internal threads 25, thereby fixing the interlayer 4 to the interior of the acetabulum 21 of the joint cavity 2. The fixing ring 5 is installed in the acetabulum 21 by means of threads, making it easy to assemble and disassemble. A plurality of micropores 53 are provided on the outer edge of the fixing ring 5. The micropores 53 are through holes that help to fix the equipment and tools. At the same time, after surgery, tissue fluid produced by the patient's body can penetrate into the dynamic stabilization system through the micropores 53, lubricating the contact points such as the joint head 1, the joint cavity 2, the cushion 3, and the interlayer 4, making the rotation of the dynamic stabilization system smoother. Over time, fibrous connective tissue will form around the dynamic stabilization system, forming a regenerative joint capsule to improve biomechanical properties. The fibrous film formed around the structure of the tissue fluid also provides biological stability to the dynamic stabilization system, thereby significantly improving patient comfort and enhancing the service life and adaptability of the stabilization system of the present invention. The material of the fixing ring 5 can be a high-strength metal material or a polymer material, such as ultra-high molecular weight polyethylene.

[0068] Connecting block 6 as Figure 11The structure shown is a columnar structure with a curved cross-section, consisting of a straight surface and a curved surface. It has the same structure as the sidewall of the connecting portion of connecting rod 26, and the diameter of the curved surface is the same as that of connecting rod 12. The straight surface is a raised contact surface 62. When the two connecting blocks 6 are symmetrically installed on the joint head 1, the raised contact surface 62 connects with the connecting block contact surface 15, and the connecting block 6 and connecting rod 12 form a cylindrical structure. A plurality of third nail channels 61 corresponding to the first nail channels 14 are evenly distributed on the connecting block 6. The fixing nails 8 anchor the connecting block 6 to the rectangular portion of the connecting rod 12 through the third nail channels 61 and the first nail channels 14. The connecting block 6 can be made of a high-strength metal or a polymer material.

[0069] Connecting shaft 7 Figure 12 As shown, its structure is identical to the rectangular parallelepiped portion of the joint head 1. A pair of opposing side surfaces of the connecting shaft 7 form through-groove contact surfaces 72, which mate with the connecting shaft contact surface 28. A plurality of fourth nail channels 71 corresponding to the first nail channels 14 are provided on the side surfaces where the through-groove contact surfaces 72 are located. The fixation nails 8 pass through the second nail channels 29 and the fourth nail channels 71 to anchor the joint cavity 2 and the connecting shaft 7 to the spine. In this embodiment, the connecting shaft 7 can be made of a high-strength metal or polymer material.

[0070] The structure of the fixing nail 8 used in this embodiment is as follows Figure 13 The cylindrical structure shown is a full thread 81 on the outside and a groove 82 at one end. The groove 82 can be a hexagonal groove or a groove of other shapes to facilitate locking with the installation tool. The fixing nail 8 can be a high-strength metal material or a polymer material.

[0071] The high-strength metal material or polymer material used in this embodiment may preferably be titanium alloy, cobalt-chromium alloy, medical stainless steel, etc.

[0072] The dynamic stabilization system in this embodiment and the pedicle screw 9 (see Figure 14 ) can be used for internal fixation in cervical, thoracic, and lumbar surgeries, as well as in spinal surgery simulation training. This dynamic stabilization system uses the same fixation method for cervical, thoracic, and lumbar surgeries, as well as spinal surgery simulation training. Different sizes of dynamic stabilization systems are used depending on the size of the cervical, thoracic, and lumbar vertebrae, as well as the simulated vertebral bodies.

[0073] In the simulation training of single segment surgery or single segment spinal surgery, the joint head 1 and the joint cavity 2 are connected in the dynamic stabilization system, and the connection block 6 and the connection shaft 7 are anchored by the fixing nail 8, such as Figure 14 As shown, the usage process is as follows:

[0074] 1. Place the cushion pad 3 in the acetabulum 21 of the joint cavity 2, and then insert the head 11 of the joint head 1 into the cushion pad 3;

[0075] 2. The interlayer 4 and the fixing ring 5 are sequentially sleeved on the joint head 1, and the joint cavity 2, the cushion 3, the interlayer 4, and the fixing ring 5 are coaxially arranged. The joint head contact surface 45 of the body 41 of the interlayer 4 is in contact with the joint head 11, and the fixing block 43 of the interlayer 4 is placed in the interlayer fixing groove 23. The neck 42 of the interlayer 4 is sleeved on the connecting rod 12, and a gap is left between the neck 42 and the connecting rod 12; the fixing ring 5 is sleeved on the neck 42 and is threadedly connected to the joint cavity 2 through the external thread 52 and the internal thread 25;

[0076] 3. The two connecting blocks 6 are symmetrically placed on both sides of the rectangular parallelepiped portion of the connecting rod 12 and fixed by fixing pins 8;

[0077] 4. Place the connecting shaft 7 into the through groove 27 of the joint cavity 2 and anchor it with the fixing pin 8;

[0078] 5. Select appropriate pedicle screws 9 based on the actual size of the cervical, thoracic, and lumbar vertebrae. On one side of the spine to be fixed, two pedicle screws 9 are respectively passed axially through the pedicles and fixed to the corresponding vertebral bodies (i.e., the vertebral bodies on the spine connected to the pedicles). The two ends of the dynamic stabilization system (i.e., the connecting rod 12 and the connecting rod 26 of the dynamic stabilization system) are respectively passed through the tail wing grooves (the grooves arranged axially on the upper part of the pedicle screw 9) of the ipsilateral pedicle screw 9, and the nuts are screwed into the tail wing to fix the dynamic stabilization system. The spine can be a real human spine or a simulated spine.

[0079] The dynamic stabilization system on the other side of the spine was combined with the pedicle screw 9 tail using the same method.

[0080] In the simulation training of multi-segment surgery or multi-segment spinal surgery, multiple dynamic stabilization systems need to be assembled and connected, such as Figure 15 As shown, the usage process is as follows:

[0081] 1. Connect the joint head 1 and the joint cavity 2 in multiple dynamic stabilization systems into a whole according to steps 1 and 2 respectively;

[0082] (1) Place the cushion pad 3 in the acetabulum 21 of the joint cavity 2, and then extend the head 11 of the joint head 1 into the cushion pad 3;

[0083] (2) The interlayer 4 and the fixing ring 5 are sequentially sleeved on the joint head 1, and the interlayer 4 is coaxial with the joint cavity 2, the cushion 3, and the fixing ring 5. The joint head contact surface 45 of the body 41 of the interlayer 4 contacts the joint head 11, and the fixing block 43 of the interlayer 4 is placed in the interlayer fixing groove 23. The neck 42 of the interlayer 4 is sleeved on the connecting rod 12, and a gap is left between the neck 42 and the connecting rod 12; the fixing ring 5 is sleeved on the neck and is threadedly connected to the joint cavity 2 through the external thread 52 and the internal thread 25;

[0084] 2. Place the rectangular parallelepiped portion of the connecting rod 12 of one dynamic stabilization system into the through slot 27 of an adjacent dynamic stabilization system and anchor it with the fixing pin 8;

[0085] 3. After multiple dynamic stabilization systems are connected to form a multi-link structure, the multi-link structure has a through slot 27 at one end, in which the connecting shaft 7 is placed and anchored by a fixing pin 8. At the other end of the multi-link structure, two connecting blocks 6 are symmetrically placed on both sides of the rectangular parallelepiped portion of the connecting rod 12 and anchored by a fixing pin 8.

[0086] 4. According to the actual size of the cervical vertebrae, thoracic vertebrae, and lumbar vertebrae, appropriate pedicle screws 9 are selected. On one side of the spine to be fixed, multiple pedicle screws 9 are respectively passed through the pedicles in the axial direction and fixed with the corresponding vertebral bodies; the multi-link structure formed by connecting multiple dynamic stabilization systems is bent according to the actual situation of the multi-segment vertebral curvature; the two ends of the dynamic stabilization system (i.e., the connecting rod 12 and the connecting rod 26 ends) are respectively passed through the grooves on the tail of the pedicle screw 9 at the same level on the same side (the grooves arranged axially on the upper part of the pedicle screw 9), and the nuts are screwed into the tail to fix the dynamic stabilization system;

[0087] The dynamic stabilization system on the other side of the spine was combined with the pedicle screw 9 tail using the same method.

[0088] Both ends of the dynamic stabilization system of this embodiment can also be anchored to non-dynamic stabilization connecting rods, thereby combining the dynamic stabilization system with traditional spinal fusion surgery, thereby facilitating the treatment of complex spinal diseases.

[0089] The dynamic stabilization system of this embodiment can also be used in combination with bone cement screws, thereby effectively improving the holding force of the internal fixation system, effectively treating osteoporosis patients, and reducing the incidence of internal fixation-related complications such as loosening, displacement, or breakage of the internal fixation system.

[0090] Although the principles of the present invention have been 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 illustrative of the present invention and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute a limitation on the scope of the present invention. Without departing from the spirit and scope of the present invention, any obvious changes such as equivalent transformations and simple substitutions based on the technical solution of the present invention fall within the scope of protection of the present invention.

Claims

1. A dynamic stabilization system for the spine, characterized in that: The dynamic stabilization system comprises a joint head (1), a joint cavity (2), a connection block (6), a connection shaft (7), and a fixing nail (8); The joint head (1) comprises a joint head portion (11) and a connecting rod (12), wherein the joint head portion (11) is fixed to one end of the connecting rod (12); the two connecting blocks (6) are symmetrically arranged on both sides of the connecting rod (12) and fixed by means of the fixing nails (8); The connecting rod (12) is composed of a cylindrical portion and a rectangular portion, the joint head portion (11) is connected to the rectangular portion via the cylindrical portion, a group of opposite side surfaces of the rectangular portion are connecting block contact surfaces (15), and a plurality of first nail tracks (14) are evenly distributed on the side surfaces where the connecting block contact surfaces (15) are located; a plurality of third nail tracks (61) corresponding to the first nail tracks (14) are evenly distributed on the connecting block (6), and the fixing nails (8) pass through the third nail tracks (61) and the first nail tracks (14) for anchoring; The joint cavity (2) comprises an acetabular cup (21) and a connecting rod (26), wherein the acetabular cup (21) is fixed to one end of the connecting rod (26); the joint head portion (11) is installed in the acetabular cup (21), and the joint head portion (11) can rotate to a predetermined bending angle in the acetabular cup (21); the connecting rod (26) has a through groove (27), and the connecting shaft (7) is placed in the through groove (27) and fixed by the fixing nail (8); The connecting rod (26) is composed of a cylindrical portion and a connecting portion, the acetabular cup (21) is connected to the connecting portion via the cylindrical portion, and the through groove (27) is arranged axially along the connecting portion; a plurality of second nail channels (29) are symmetrically and evenly distributed on both side walls of the connecting portion, a plurality of fourth nail channels (71) corresponding to the second nail channels (29) are arranged on the connecting shaft (7), and the fixing nail (8) passes through the second nail channels (29) and the fourth nail channels (71) for anchoring; The dynamic stabilization system is fixed to the corresponding vertebral body of the spine via pedicle screws (9).

2. The dynamic stabilization system for the spine according to claim 1, characterized in that: The dynamic stabilization system further comprises a cushion (3); a gap is left between the joint head (11) and the acetabulum (21), and the cushion (3) is filled in the gap.

3. The dynamic stabilization system for the spine according to claim 1, characterized in that: The dynamic stabilization system further comprises an interlayer (4) and a fixing ring (5); the interlayer (4) and the fixing ring (5) are sequentially sleeved on the joint head (1); the fixing ring (5) is fixedly installed in the acetabulum (21) to press the interlayer (4) onto the joint head (11).

4. The dynamic stabilization system for the spine according to claim 3, characterized in that: The interlayer (4) comprises a body (41), a neck (42), and a fixing block (43); the neck (42) is coaxially arranged at the end of the body (41); a plurality of fixing blocks (43) are evenly distributed around the outer side of the body (41); the body (41) is in contact with the joint head (11); the neck (42) is sleeved on the connecting rod (12); and the fixing block (43) is installed in a plurality of interlayer fixing grooves (23) evenly distributed around the acetabulum (21).

5. The dynamic stabilization system for the spine according to claim 4, characterized in that: The fixing ring (5) comprises a through hole (51), an external thread (52), and micro holes (53); the fixing ring (5) is sleeved on the body (41) through the through hole (51), and the fixing ring (5) is threadedly connected to the internal thread (25) at one end of the acetabulum (21) through the external thread (52); a plurality of micro holes (53) are evenly distributed around the fixing ring (5).

6. The dynamic stabilization system for the spine according to claim 1, characterized in that: The acetabulum (21) is a hollow cylindrical structure. A joint surface (22) is provided at one end of the acetabulum (21). The acetabulum (21) is connected to the connecting rod (26) via the joint surface (22).

7. A method for using a dynamic stabilization system for the spine according to any one of claims 1 to 6, characterized in that: In the simulation training of single-segment spinal surgery, the method of using the dynamic stabilization system includes the following steps: (1), placing the cushion pad (3) in the acetabulum (21) of the joint cavity (2), and then extending the joint head (11) of the joint head (1) into the cushion pad (3); (2), the interlayer (4) and the fixing ring (5) are sleeved on the joint head (1) in sequence, and the joint cavity (2), the buffer pad (3), the interlayer (4) and the fixing ring (5) are coaxially arranged, the body (41) of the interlayer (4) is connected to the head of the joint head (11), and the fixing block (43) of the interlayer (4) is placed in the interlayer fixing groove (23), the neck (42) of the interlayer (4) is sleeved on the connecting rod (12), and a gap is left between the connecting rod (12); the fixing ring (5) is sleeved on the neck (42) and is threadedly connected to the joint cavity (2); (3) Two connecting blocks (6) are symmetrically placed on both sides of the rectangular parallelepiped portion of the connecting rod (12) and anchored by fixing pins (8); (4) The connecting shaft (7) is placed in the through groove (27) of the joint cavity (2) and anchored by a fixing pin (8); (5) selecting pedicle screws (9) corresponding to the spine to be fixed; on one side of the spine, two pedicle screws (9) are respectively passed through the pedicles and fixed to the corresponding vertebral bodies; two ends of the dynamic stabilization system are respectively passed through the tail grooves of the pedicle screws (9) on the same side, and are screwed into the tail through nuts for fixation, wherein the spine is a simulated spine; The dynamic stabilization system on the other side of the spine is combined with the tail of the pedicle screw (9) in the same manner.

8. The method for using the dynamic stabilization system for the spine according to claim 7, characterized in that: In the simulation training of multi-segment spinal surgery, multiple dynamic stabilization systems need to be used, and the method of using includes the following steps: S1, the joint heads (1) and the joint cavities (2) in the multiple dynamic stabilization systems are connected together according to the steps (1) and (2) in the simulation training of single-segment spinal surgery; S2, placing the rectangular parallelepiped portion of the connecting rod (12) of one dynamic stabilization system in the through groove (27) of the adjacent dynamic stabilization system and anchoring it via the fixing pin (8); S3. After a plurality of dynamic stabilization systems are connected to form a multi-link structure, the multi-link structure has one end with a through slot (27), the connecting shaft (7) is placed in the through slot (27), and is anchored by a fixing nail (8); at the other end of the multi-link structure, two connecting blocks (6) are symmetrically placed on both sides of the rectangular parallelepiped portion of the connecting rod (12), and are anchored by a fixing nail (8); S4, selecting pedicle screws (9) corresponding to the spine to be fixed; on one side of the spine to be fixed, multiple pedicle screws (9) are respectively passed through the pedicles and fixed to the corresponding vertebral bodies; the multi-link structure formed by connecting multiple dynamic stabilization systems is bent according to the actual situation of the curvature of the multi-segment vertebral bodies; the two ends of the dynamic stabilization system are respectively passed through the grooves on the tail of the pedicle screws (9) at the same level on the same side, and are screwed into the tail through nuts for fixation; The dynamic stabilization system on the other side of the spine is combined with the tail of the pedicle screw (9) in the same manner.

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