Posterior cervical spinal canal expansion titanium plate fixing system

Abstract

The invention discloses a posterior cervical spinal canal expansion titanium plate fixing system, and relates to the technical field of orthopedic implants. Aiming at the following three problems of an existing titanium plate, the titanium plate is improved and designed, so that the problem of axial pain after a posterior cervical approach in clinic can be effectively reduced: the existing posterior cervical approach titanium plate is lack of a posterior complex repairing and anchoring structure, so that the posterior cervical extensor muscle amount is insufficient, and the physiological curvature is lost; the side block end of an existing titanium plate is fixedly installed through two screws, the joint capsule stripping range is large, the penetration rate of the screws on the articular surface reaches 30%, and arthritis is caused. An existing titanium plate is too high in elasticity modulus, and activity stress is concentrated on the door shaft side, so that a door shaft is not healed. The device comprises a main body supporting plate, a vertebral plate end fixing plate, a lateral mass end fixing plate, a rear complex anchoring titanium wire, a lateral mass end extending double-clamping groove and a fixing buckle. The vertebral plate end fixing plate and the lateral mass end fixing plate are arranged in parallel, the vertebral plate end fixing plate and the lateral mass end fixing plate are connected through the obliquely-arranged main body supporting plate, and the vertebral plate supporting device is used for supporting the vertebral plate after the cervical spondyloplasty.

Description

Technical Field

[0001] The present invention relates to the technical field of orthopedic implants, and particularly relates to a posterior cervical spinal canal expansion titanium plate fixation system. Background Art

[0002] Cervical spinal stenosis is a multi-factorial syndrome in which the spinal canal volume decreases, compressing the spinal cord and causing varying degrees of neurological dysfunction. It can be developmental, but more often secondary to degeneration, deformity, trauma, etc. According to statistics, the incidence rate in adults in China is 4.9%, and as high as 26% in the elderly. This disease has a high disability rate, seriously endangering the quality of life and working ability of patients, and bringing a heavy burden to families and society. The posterior cervical titanium plate-assisted laminoplasty is the preferred treatment for multi-segmental cervical spinal stenosis with neurological symptoms, with advantages such as safety and definite curative effect. However, 20% - 30% of patients experience axial pain after surgery, such as neck and shoulder stiffness, pain accompanied by limited movement, which seriously affects the quality of life.

[0003] The occurrence of axial pain is closely related to factors such as injury to the posterior complex, injury to the lateral mass joints, and non-union of the hinge axis.

[0004] Traditional titanium plates do not have a posterior complex repair structure; the lateral mass end uses double-screw fixation, with extensive dissection of the joint capsule, and the penetration rate of the articular surface screws reaches 30%; the titanium plate has a high elastic modulus, and strain is concentrated at the hinge axis, making non-union prone to occur. These defects cause axial pain to varying degrees. Summary of the Invention

[0005] The present invention improves the design structure and material in view of the defects of the existing titanium plates: the new titanium plate has an anchor structure for the posterior complex, which increases the strength of the posterior cervical muscles and improves the physiological curvature of the cervical spine; the lateral mass end is fixed by a double-groove on the osteotomy surface in cooperation with a single screw, achieving three-point stability, reducing the dissection range of the lateral mass joint capsule and the penetration rate of the articular surface screws; a titanium alloy with a low elastic modulus is used to reduce the active stress on the hinge axis side and reduce the non-union rate of the hinge axis. Through the above three improvements, the problems raised in the above background art are solved.

[0006] The technical solution of the present invention is as follows:

[0007] A posterior cervical spinal canal expansion titanium plate fixation system, which includes a main support plate, a lamina end fixing plate and a lateral mass end fixing plate, an anchor titanium wire for the posterior complex, an extended double-groove at the lateral mass end, and a fixing buckle;

[0008] The lamina end fixing plate and the lateral mass end fixing plate are arranged in parallel, and the lamina end fixing plate and the lateral mass end fixing plate are connected by an inclined main support plate. Two lamina end bone screw mounting holes are provided on the lamina end fixing plate, and a lateral mass end bone screw mounting hole is provided on the lateral mass end fixing plate;

[0009] The end of the lamina end fixing plate is provided with several posterior complex anchoring titanium wires, and the fixing buckle fixedly connects the ends of the two posterior complex anchoring titanium wires. A side mass end extended double card slot is arranged below the side mass end fixing plate.

[0010] Furthermore, a lamina end support foot is arranged at the connection between the main body support plate and the lamina end fixing plate.

[0011] Furthermore, the lamina end support foot is in a semi-circular arc structure, and the lamina end support feet are tangent to the main body support plate and the lamina end fixing plate respectively.

[0012] Furthermore, the side mass end extended double card slot forms an acute angle with the side mass end fixing plate, and the side mass end extended double card slot is composed of two rectangular plate-like structures.

[0013] Furthermore, the included angle between the main body support plate and the lamina end fixing plate is 130°, and the included angle between the side mass end fixing plate and the side mass end extended double card slot is 80°.

[0014] Furthermore, the width of the side mass end extended double card slot is greater than that of the side mass end fixing plate.

[0015] Furthermore, the central connection line of the two lamina end bone screw mounting holes is arranged along the length direction of the lamina end fixing plate.

[0016] Furthermore, the side mass end fixing plate is provided with a single side mass end bone screw mounting hole, and the center line of the side mass end bone screw mounting hole is arranged along the width direction of the side mass end fixing plate.

[0017] Furthermore, the left and right sides of the lamina end fixing plate between the two lamina end bone screw mounting holes contract inward.

[0018] Furthermore, the posterior cervical spinal canal expansion titanium plate fixation system adopts a titanium alloy material, and the elastic modulus of the titanium alloy material is 30 Gp.

[0019] The present invention has the following beneficial effects compared with the prior art:

[0020] 1. A posterior cervical spinal canal expansion titanium plate fixation system solves the problem of the posterior complex repair structure. None of the existing products have a spinous process anchoring device, and the repair of the posterior complex is the basis for the posterior cervical muscles to play a role and maintain the physiological curvature to avoid axial pain. Clinically, using titanium cables to pass through the titanium plate holes to anchor the spinous process will cause the risk of interface cutting and fracture between different materials. After surgery, neck immobilization is required, resulting in muscle fibrosis and joint adhesion, and causing axial pain. The titanium plate of the present invention is designed with a double-titanium-wire anchoring structure, which can be flexibly applied according to the characteristics of the spinous process of Chinese people, firmly anchored, repair the posterior complex, and at the same time realize early functional exercise.

[0021] 2. Solve the problem of joint injury caused by the lateral mass anchoring structure. In the existing titanium plate, two screws are required to cooperate with a right-angle card slot at the lateral mass end to achieve stability. The degree of joint capsule dissection is large, and the penetration rate of the joint surface screws reaches 30%, leading to arthritis and axial pain. This titanium plate uses an extended acute double card slot and a single screw for fixation. The main structure is moved to the osteotomy surface, and only one short screw is needed for effective fixation. The range of joint capsule dissection is small, and the penetration rate of the joint surface screws is greatly reduced.

[0022] 3. Solve the problem of too high elastic modulus ratio of the titanium plate / lamina. At present, the elastic modulus of the titanium alloy used in the titanium plate is about 110 GPa, which is 30 times higher than that of the lamina cancellous bone, resulting in stress concentration at the hinge axis, which is likely to cause non-union of the hinge axis and even collapse of the surgical failure. Based on the measurement of the elastic modulus of the lamina of Chinese people in a large sample, this titanium plate selects a titanium alloy with a low elastic modulus, and the elastic modulus of the finished product is controlled within 2 times that of the lamina, which can greatly reduce the stress at the hinge axis and avoid non-union of the hinge axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural view of the cervical posterior spinal canal expansion titanium plate fixation system Figure Ⅰ ;

[0024] Figure 2 is a schematic structural view of the cervical posterior spinal canal expansion titanium plate fixation system Figure Ⅱ ;

[0025] Figure 3 is the front view of the cervical posterior spinal canal expansion titanium plate fixation system;

[0026] Figure 4 is the top view of the cervical posterior spinal canal expansion titanium plate fixation system;

[0027] Figure 5 is the side view of the cervical posterior spinal canal expansion titanium plate fixation system;

[0028] Figure 6 is the schematic structural view of the fixing buckle;

[0029] Figure 7 is the schematic structural view of the installation bolt of the cervical posterior spinal canal expansion titanium plate fixation system.

[0030] In the figure: 1. Main body support plate; 2. Lamina end fixing plate; 3. Lamina end bone screw installation hole; 4. Posterior complex anchoring titanium wire; 5. Lamina end support foot; 6. Lateral mass end fixing plate; 7. Lateral mass end bone screw installation hole; 8. Lateral mass end extended double card slot; 9. Fixing buckle. DETAILED DESCRIPTION OF THE INVENTION

[0031] Detailed Description of the Invention One: Refer to Figures 1-7As shown, a posterior cervical spinal canal expansion titanium plate fixation system. This embodiment includes a main support plate 1, a lamina end fixing plate 2, a lateral mass end fixing plate 6, a posterior complex anchoring titanium wire 4, a lateral mass end extension double card slot 8, and a fixing buckle 9;

[0032] The lamina end fixing plate 2 and the lateral mass end fixing plate 6 are arranged in parallel. The lamina end fixing plate 2 and the lateral mass end fixing plate 6 are connected by an inclined main support plate 1. Two lamina end bone screw mounting holes 3 are provided on the lamina end fixing plate 2, and a lateral mass end bone screw mounting hole 7 is provided on the lateral mass end fixing plate 6;

[0033] Several posterior complex anchoring titanium wires 4 are provided at the end of the lamina end fixing plate 2. The fixing buckle 9 is fixedly connected to the ends of the two posterior complex anchoring titanium wires 4. A lateral mass end extension double card slot 8 is provided below the lateral mass end fixing plate 6.

[0034] Specific Embodiment Two: Refer to Figures 1-5 As shown, a lamina end support foot 5 is provided at the connection between the main support plate 1 and the lamina end fixing plate 2 in this embodiment.

[0035] Specific Embodiment Three: Refer to Figures 1-5 As shown, the lateral mass end fixing plate 6 in this embodiment is provided with a single lateral mass end bone screw mounting hole 7, and the center line of the lateral mass end bone screw mounting hole 7 is arranged along the width direction of the lateral mass end fixing plate 6.

[0036] Specific Embodiment Four: Refer to Figures 1-5 As shown, the left and right sides of the lamina end fixing plate 2 between the two lamina end bone screw mounting holes 3 contract inward in this embodiment.

[0037] Furthermore, the main support plate 1, the lamina end fixing plate 2, and the lateral mass end fixing plate 6 are integrally formed. The lamina end fixing plate 2 and the lateral mass end fixing plate 6 are staggered up and down and arranged in parallel. The main support plate 1 is inclined. On the lateral mass end fixing plate 6 fixed to the cervical lateral mass, a single lateral mass end bone screw mounting hole 7 is provided to reduce the penetration of the articular surface screw and reduce the axial pain caused by arthritis. The posterior complex anchoring titanium wire 4 is integrally formed with the lamina end fixing plate 2 and is a flexible structure. Two posterior complex anchoring titanium wires 4 are provided in this invention, and are symmetrically arranged on both sides of the end of the lamina end fixing plate 2 respectively. Two round holes are provided on the fixing buckle 9. The two posterior complex anchoring titanium wires 4 respectively pass through the two round holes on the fixing buckle 9. The posterior complex anchoring titanium wire 4 is in interference fit in the round holes, fixing the ends of the two posterior complex anchoring titanium wires 4 together to form a ring structure. Two protrusions are provided on both sides of the fixing buckle 9. During use, the protrusions can be embedded into the bone surface layer to increase the anchoring effect.

[0038] Furthermore, existing products do not have spinous process anchoring devices, and the repair of the posterior complex is the basis for the posterior cervical muscles to play a role, maintain physiological curvature and avoid axial pain. The use of titanium cables through the holes of titanium plates to anchor the spinous process in clinical practice will produce the risk of cutting and breaking the interface between different materials. The neck needs to be immobilized after surgery, which leads to muscle fibrosis, joint adhesion, and axial pain. The titanium wire 4 for anchoring the posterior complex of the titanium plate is used to anchor the spinous process. It can be flexibly applied and firmly anchored according to the characteristics of the spinous process of Chinese people, repairing the posterior complex and realizing early functional training at the same time. Application method: a titanium wire can pass through the guide to bypass the spinous process from below the spinous process osteotomy surface, the supraspinous ligament and another titanium wire are tightened through the double holes of the buckle, and the buckle is clamped to realize the anchoring of the posterior complex; the spinous process is pre-drilled, and a titanium wire is passed through the guide to bypass the spinous process osteotomy surface from below, pass through the prefabricated hole of the spinous process, and merge with another titanium wire through the double holes of the buckle to tighten, and the buckle is clamped to realize the anchoring of the posterior complex.

[0039] Specific implementation method five: see Figures 1-5 As shown, the extended double card slot 8 at the side block end of this embodiment forms an acute angle with the side block end fixing plate 6, and the extended double card slot 8 at the side block end is two rectangular plate-like structures, and the side view of the card slot is a wedge-shaped structure, and the tip of the wedge is the distal end, which can be inserted into the osteotomy cancellous bone surface to increase stability.

[0040] Specific implementation method six: see Figures 1-5 As shown, in this embodiment, the angle between the main support plate 1 and the vertebral plate end fixation plate 2 is 130°, the angle between the side block end fixation plate 6 and the main support plate 1 is 130°, and the angle between the side block end fixation plate 6 and the side block end extended double card slot 8 is 80°.

[0041] Specific implementation method seven: See Figures 1-5 As shown, the width of the extended double slot 8 at the side block end of this embodiment is greater than that of the side block end fixing plate 6 .

[0042] Furthermore, the extended double slots 8 at the side block end are at an acute angle to the fixing plate 6, with a specific angle of 80°. When the fixing plate 6 at the side block end is fixed to the side block, the extended double slots 8 at the side block end are pressed against the osteotomy surface at the transition of the vertebral plates of the side block, and the lateral force between most of the bolts and the cervical vertebrae is transferred to the supporting force between the osteotomy surface of the cervical vertebrae and the extended double slots 8 at the side block end, reducing the force on the screws, thereby reducing the existing double screw fixation to single screw fixation, achieving a small range of joint capsule stripping, and greatly reducing the penetration rate of articular surface screws. The extended double slots 8 at the side block end are set as two rectangular plate-like structures, which are longer than the traditional slots and wider than the fixing plate 6 at the side block end, increasing the contact area between the extended double slots 8 at the side block end and the osteotomy surface of the cervical vertebra. The separated double slots are conducive to matching irregular osteotomy surfaces and increasing the fit. The side view is wedge-shaped, and the tip can be inserted into the osteotomy surface to increase stability.

[0043] Specific implementation method eight: SeeFigures 1-5 As shown, a lamina end support foot 5 is provided at the connection between the main body support plate 1 and the lamina end fixing plate 2 of this embodiment.

[0044] Specific implementation method nine: See Figures 1-5 As shown, the lamina end support legs 5 of this embodiment are semicircular arc structures, and the lamina end support legs 5 are tangent to the main support plate 1 and the lamina end fixing plate 2 respectively.

[0045] Furthermore, the vertebral plate end support leg 5 is an arc structure, which is used to buckle the cervical vertebral plate to play a supporting role. The vertebral plate end support leg 5 of the arc structure contacts the vertebral plate wound surface softly and bears force evenly. It is compatible with vertebral plates with different thicknesses and has a wide range of applications. The arc structure can fit the corresponding position of the cervical vertebral plate, provide strong support for the micro titanium plate, effectively prevent the door from closing again or reducing the opening angle after surgery, maintain the effect of expanding the spinal canal, and achieve effective decompression inside the spinal canal.

[0046] Specific implementation method ten: See Figures 1-4 As shown, the posterior cervical spinal canal enlargement titanium plate fixation system of this embodiment is made of titanium alloy, and the elastic modulus of the titanium alloy is 30Gp.

[0047] Furthermore, this posterior cervical spinal canal enlargement titanium plate fixation system uses β-titanium alloy Ti2448, the elastic modulus of which is 30Gp. It is the first time that a low elastic modulus titanium alloy that is more compatible with the elastic modulus of the vertebral plate is used. The current titanium plate material is Ti-6Al-4V ELI high-strength damage-tolerant titanium alloy, with an elastic modulus of about 110GPa, which is about 30 times higher than the cancellous bone of the vertebral plate, causing severe stress shielding of the bone, causing deformation stress to be concentrated on the portal axis, which can easily lead to portal axis nonunion and even portal axis collapse and surgical failure. This titanium plate uses a low elastic modulus titanium alloy based on the elastic modulus of the Chinese vertebral plate measured in a large sample. The elastic modulus of the finished product is controlled within 2 times of the vertebral plate, which greatly reduces stress shielding and portal axis deformation stress, facilitates intraoperative shaping, reduces portal axis nonunion, and improves the success rate of the operation.

[0048] When in use, the extended double slots 8 at the side block end are used to press against the osteotomy wound of the cervical vertebra, and the support legs 5 at the vertebral plate end are used to buckle the osteotomy wound of the vertebral plate. Three bolts are used to pass through the two vertebral plate end bone screw mounting holes 3 and the side block end bone screw mounting holes 7 respectively to fix the enlarged titanium plate fixation system. A posterior complex anchoring titanium wire 4 is used to penetrate the spinous process separated during the operation and merge with another posterior complex anchoring titanium wire 4 on the opposite side. A clamping device is used to fix the two posterior complex anchoring titanium wires 4 to achieve effective bundling of the spinous process to anchor the posterior complex.

Claims

1. A titanium plate fixation system for posterior cervical spinal canal enlargement, comprising a main support plate (1), a vertebral plate end fixation plate (2) and a lateral mass end fixation plate (6), characterized in that: It also includes a rear complex anchoring titanium wire (4), a side block end extended double slot (8) and a fixing buckle (9); The vertebral plate end fixing plate (2) and the lateral mass end fixing plate (6) are arranged in parallel, the vertebral plate end fixing plate (2) and the lateral mass end fixing plate (6) are connected via an inclined main body support plate (1), the vertebral plate end fixing plate (2) is provided with two vertebral plate end bone screw mounting holes (3), and the lateral mass end fixing plate (6) is provided with a lateral mass end bone screw mounting hole (7); Two rear complex anchoring titanium wires (4) are arranged at the end of the vertebral plate end fixing plate (2), a fixing buckle (9) is fixedly connected to the ends of the two rear complex anchoring titanium wires (4), and a side block end extended double card slot (8) is arranged below the side block end fixing plate (6).

2. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The connection between the main body support plate (1) and the lamina end fixing plate (2) is provided with a lamina end support foot (5).

3. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 2, characterized in that: The vertebral plate end support feet (5) are semicircular arc structures, and the vertebral plate end support feet (5) are tangent to the main body support plate (1) and the vertebral plate end fixing plate (2) respectively.

4. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The extended double card slots (8) at the side block end form an acute angle with the side block end fixing plate (6), and the extended double card slots (8) at the side block end are two rectangular plate-shaped structures.

5. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 4, characterized in that: The included angle between the main body support plate (1) and the vertebral plate end fixing plate (2) is 130°, and the included angle between the side block end fixing plate (6) and the side block end extended double card slot (8) is 80°.

6. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The width of the extended double slot (8) at the side block end is greater than the side block end fixing plate (6).

7. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The center line of the two vertebral plate end bone screw mounting holes (3) is arranged along the length direction of the vertebral plate end fixing plate (2).

8. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The side mass end fixing plate (6) is provided with a single side mass end bone screw mounting hole (7), and the center line of the side mass end bone screw mounting hole (7) is arranged along the width direction of the side mass end fixing plate (6).

9. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 7, characterized in that: The left and right sides of the vertebral plate end fixing plate (2) between the two vertebral plate end bone screw mounting holes (3) are retracted inwards.

10. The titanium plate fixation system for posterior cervical spinal canal enlargement according to claim 1, characterized in that: The posterior cervical spinal canal enlargement titanium plate fixation system is made of titanium alloy, and the elastic modulus of the titanium alloy is 30Gp.

Images