An internal fixation device for minimally invasive fixation and fusion of lumbar facet joints

Abstract

The present application relates to the technical field of orthopedic fixation devices, and specifically discloses an internal fixation device for lumbar facet joint minimally invasive fixation and fusion, which comprises rotationally connected upper anchoring parts, lower anchoring parts and connecting parts. The upper anchoring parts and the lower anchoring parts are respectively attached to the upper and lower articular process bone surfaces of adjacent vertebral bodies, and are respectively provided with lamina notches and inner wall anti-displacement structures to improve the initial implant stability. The connecting parts are all equipped with compression locking structures to achieve stable fixation of the articular process joints. At the same time, the device is provided with reinforced fixation buckles matched with the clamping grooves to further improve the fixation effect. The present application adopts a minimally invasive low-profile design, causes little damage to soft tissues, concentrates the fixation path, effectively reduces bone stress shielding, and can also rely on the matching structure to improve the bone integration and bone fusion efficiency, accurately solves the articular process joint source pain, is convenient to operate during the operation, and is suitable for use in lumbar facet joint minimally invasive fusion surgery.

Description

Technical Field

[0001] This invention relates to the field of orthopedic fixation device technology, specifically to an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine. Background Technology

[0002] Lumbar facet joint arthritis and mild lumbar spondylolisthesis are common causes of chronic low back pain. Currently, posterior lumbar interbody fusion combined with pedicle screw fixation is the "gold standard" for treating severe cases. This technique achieves deformity reduction and spinal stability by providing strong internal fixation, and ultimately pursues bony fusion.

[0003] However, rigid fixation has significant inherent drawbacks: First, it completely sacrifices the physiological range of motion of the fixed segment, which may lead to postoperative lumbar stiffness and poor functional experience in patients; second, due to stress shielding and stress transfer, rigid fixation bears most of the mechanical load, causing disuse osteoporosis in the fixed segment and abnormally increasing the stress on the intervertebral discs and joints of adjacent segments, thereby accelerating the degeneration of adjacent segments. Some patients may need to undergo surgery again several years later due to adjacent vertebral disease.

[0004] Therefore, the field of spinal surgery has been exploring solutions that can balance "stability" and "mobility." Dynamic stabilization systems (such as flexible fixation and interspinous distraction devices) have emerged to address this need. Their goal is to control abnormal movement, relieve pain, preserve a certain degree of physiological range of motion, and reduce adverse effects on adjacent segments. However, most existing dynamic stabilization devices focus on regulating the intervertebral disc or the entire musculoskeletal unit, lacking means to directly address and target the pain source—the facet joints (facet joints).

[0005] Therefore, there is an urgent need in this field for a new type of implant that can provide sufficient stability while preserving a certain degree of mobility in the surgical segment, just like a dynamic stabilization system, and can also specifically treat and fuse the diseased facet joints to eliminate pain at its source, while delaying the degeneration of the intervertebral disc by reducing the stress on the intervertebral disc. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing rigid fixation and dynamic stabilization technologies and provide an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine. By fusing the facet joints, reliable stability is provided while preserving some physiological mobility of the surgical segment, and stress on the intervertebral discs of the surgical segment and adjacent segments is effectively reduced, so as to achieve the biomechanical effect of delaying intervertebral disc degeneration and reducing the occurrence of adjacent vertebral diseases.

[0007] To achieve the above objectives, the technical solution provided by the present invention is as follows: an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine, comprising an upper anchoring part for fitting and fixing to the upper facet bone surface of the adjacent vertebral body and a lower anchoring part for fitting and fixing to the lower facet bone surface of the adjacent vertebral body, wherein the upper anchoring part and the lower anchoring part are rotatably connected by a connecting part.

[0008] Furthermore, the top of the upper anchoring part is provided with a superior vertebral laminar notch, and both the upper anchoring part and the lower anchoring part are provided with a inferior vertebral laminar notch.

[0009] Furthermore, both the upper anchoring part and the lower anchoring part have anti-displacement structures on their inner walls.

[0010] Furthermore, the anti-displacement structure has anti-slip teeth, ratchet teeth, limiting protrusions, anti-reverse shoulder, or anti-rotation side wings.

[0011] Furthermore, the connecting part includes a central rotating part and a first anchoring auxiliary rotating part and a second rivet auxiliary rotating part located on both sides and rotatably connected thereto; the central rotating part, the first anchoring auxiliary rotating part and the second rivet auxiliary rotating part are all provided with a pressure locking structure.

[0012] Furthermore, the pressure locking structure includes one or more of the following: a locking buckle, a threaded clamping element, a ratchet locking element, or a wedge-shaped locking element.

[0013] Furthermore, it also includes a reinforced fixing buckle, wherein the outer walls of the upper anchoring part and the lower anchoring part are provided with a slot, and the two ends of the reinforced fixing buckle are respectively inserted into the slots on the corresponding sides to further press and fix the upper anchoring part and the lower anchoring part.

[0014] The advantages of this invention compared to the prior art are: This invention acts directly on the diseased facet joints, and can specifically address the source of small joint pain; This invention achieves complete fixation of the facet joint through a pressure-locking structure, which is beneficial for the formation of bony fusion; This invention improves bone integration efficiency through bone graft receiving cavity, through hole and guide bone surface treatment; This invention reduces the dissection and damage to muscles and soft tissues during posterior surgery through a low-profile, minimally invasive, and adaptable design. Compared to the traditional pedicle screw-connector rod large-configuration fixation system, this device is smaller in size, has a more concentrated action path, and can be combined with materials with elastic modulus close to that of bone, thereby helping to reduce stress shielding. This invention improves stability during the initial implantation stage and ease of intraoperative operation through an anti-displacement structure. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to the present invention. Figure 1 .

[0016] Figure 2 This is a schematic diagram of the internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to the present invention. Figure 2 .

[0017] Figure 3 This is a front view of an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine according to the present invention.

[0018] Figure 4 This is a rear view of an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine, according to the present invention.

[0019] Figure 5 This is a bottom view of an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine, according to the present invention.

[0020] As shown in the figure: 1. Upper anchoring part, 2. Lower anchoring part, 3. Connecting part, 4. Upper vertebral body lamina notch, 5. Lower vertebral body lamina notch, 6. Anti-displacement structure, 7. Central rotating part, 8. First anchoring auxiliary rotating part, 9. Second rivet auxiliary rotating part, 10. Pressure locking structure, 11. Reinforced fixing buckle, 12. Slot. Detailed Implementation

[0021] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0022] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0024] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] In the description of this invention, "first feature" and "second feature" may include one or more of the indicated features. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of the indicated features.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] The following is a detailed description of an internal fixation device for minimally invasive fixation and fusion of the facet joints of the lumbar spine, with reference to the accompanying drawings.

[0029] Combined with appendix Figure 1-5 This invention will be described in detail below.

[0030] An internal fixation device for minimally invasive fixation and fusion of the lumbar facet joint includes an upper anchoring part 1, a lower anchoring part 2, and a connecting part 3. The upper anchoring part 1 is fitted and fixed to the superior facet joint surface of the adjacent vertebra, and the lower anchoring part 2 is fitted and fixed to the inferior facet joint surface of the adjacent vertebra. The upper anchoring part 1 and the lower anchoring part 2 are rotatably connected through the connecting part 3 to form a stable fixation across the diseased facet joint after implantation. The upper anchoring part 1, the lower anchoring part 2, and the connecting part 3 of this invention are preferably made of medical-grade titanium alloy.

[0031] The upper anchoring part 1 has an upper vertebral lamina notch 4 at its top, and the lower vertebral lamina notch 5 is also provided at the corresponding positions of the upper anchoring part 1 and the lower anchoring part 2. The multiple lamina notches can accurately match the contour structure of the vertebral body and lamina, eliminate the gap between the instrument and the bone surface, improve the installation stability, and adapt to vertebral bodies and lamina of different sizes and shapes, thus broadening the clinical application scenarios.

[0032] Both the upper anchoring part 1 and the lower anchoring part 2 have anti-displacement structures 6 on their inner walls. In this embodiment, the anti-displacement structure 6 can be any one or more combinations of anti-slip teeth, ratchet teeth, limiting protrusions, anti-retraction shoulders, or anti-rotation wings. This anti-displacement structure 6 is used to improve the mechanical stability in the early stages of implantation and prevent the device from shifting forward, backward, left, right, or in the rotational direction.

[0033] The connecting part 3 includes a central rotating part 7, a first anchoring auxiliary rotating part 8, and a second rivet-assisted rotating part 9. The first anchoring auxiliary rotating part 8 and the second rivet-assisted rotating part 9 are symmetrically distributed on both sides of the central rotating part 7 and are rotatably connected to the central rotating part 7. Through the cooperation of the three rotating structures, multi-angle and multi-dimensional micro-adjustment of the upper anchoring part 1 and the lower anchoring part 2 can be achieved, perfectly adapting to the anatomical morphology of the facet joint in lumbar flexion, extension, and rotation states. At the same time, the central rotating part 7, the first anchoring auxiliary rotating part 8, and the second rivet-assisted rotating part 9 are all equipped with a pressure locking structure 10, which can press the upper anchoring part 1 and the lower anchoring part 2 together during implantation, thereby forming a continuous compression effect on the facet joint after cartilage and cortex removal.

[0034] The pressure locking structure 10 employs one or more of the following: locking buckle, threaded clamping element, ratchet locking element, or wedge locking element. After locking, it can maintain the complete fixation of the facet joint and prevent loosening after implantation.

[0035] To further enhance the fixation effect, this device is equipped with a reinforced fixation buckle 11. The outer walls of the upper anchoring part 1 and the lower anchoring part 2 are provided with slots 12 that match the two ends of the reinforced fixation buckle 11. After the basic fixation and pressure locking are completed, the two ends of the reinforced fixation buckle 11 are respectively inserted into the slots 12 on the corresponding sides. The clamping force of the buckle further presses the upper anchoring part 1 and the lower anchoring part 2, making the device fit more closely to the bone surface, forming a double-layer locking fixation structure, which greatly improves the overall fixation strength and meets the fixation requirements of high load and high stability.

[0036] The specific implementation process of the internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to the present invention is as follows: Step 1: Surgical approach and exposure The patient is placed in a prone position. Through a posterior midline incision or bilateral paramidline incisions, the muscle tissue is dissected layer by layer to expose the posterior structures of the target lumbar vertebral segment, especially the facet joints that need to be treated.

[0037] Step 2: Preparation of facet joints Decorticization: Using a high-speed drill or chisel, the cartilage surface of the diseased facet joint is completely removed, and the facet joint is appropriately modified.

[0038] Step 3: Implantation of the internal fixation device Placed on the prepared articular process joint.

[0039] Compression and Fixation: Using a specialized implant clamping / compression device, the upper anchoring part 1 and lower anchoring part 2 of the fusion module are precisely aligned with the superior and inferior articular processes. Appropriate pressure is applied by the device to embed the anti-displacement structure 6 (such as a ratchet) into the bone, achieving initial mechanical stability and preventing anterior-posterior and lateral displacement. The built-in pressure locking structure 10 is then activated to securely lock the upper anchoring part 1, lower anchoring part 2, and connecting part 3, forming a complete, dynamically stable structure spanning the posterior aspect of the spine.

[0040] Step 4: Install the fixing clips Connect the two ends of the reinforced fixing buckle 11 (such as a PEEK elastic connecting rod) to the slots 12 on the outer walls of the upper anchoring part 1 and the lower anchoring part 2 that have been installed on the left and right sides.

[0041] Step 5: Close the incision Completely stop the bleeding, rinse the surgical area, place a drainage tube (if necessary), and finally suture the muscles, fascia, subcutaneous tissue, and skin layer by layer.

[0042] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints, characterized in that: It includes an upper anchoring part (1) for attaching and fixing to the upper articular process bone surface of the adjacent vertebra and a lower anchoring part (2) for attaching and fixing to the lower articular process bone surface of the adjacent vertebra, wherein the upper anchoring part (1) and the lower anchoring part (2) are rotatably connected by a connecting part (3).

2. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 1, characterized in that: The upper anchoring part (1) has an upper vertebral lamina notch (4) at its top, and both the upper anchoring part (1) and the lower anchoring part (2) have a lower vertebral lamina notch (5).

3. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 2, characterized in that: The inner walls of both the upper anchoring part (1) and the lower anchoring part (2) are provided with anti-displacement structures (6).

4. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 3, characterized in that: The anti-displacement structure (6) is an anti-slip tooth, a ratchet, a limiting protrusion, a backstop shoulder, or an anti-rotation side wing.

5. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 4, characterized in that: The connecting part (3) includes a central rotating part (7) and a first anchoring auxiliary rotating part (8) and a second rivet auxiliary rotating part (9) located on both sides and rotatably connected thereto; the central rotating part (7), the first anchoring auxiliary rotating part (8) and the second rivet auxiliary rotating part (9) are all provided with a pressure locking structure (10).

6. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 5, characterized in that: The pressure locking structure (10) includes one or more of the following: a locking buckle, a threaded clamping element, a ratchet locking element, or a wedge locking element.

7. The internal fixation device for minimally invasive fixation and fusion of the lumbar facet joints according to claim 6, characterized in that: It also includes a reinforced fixing buckle (11), and the outer walls of the upper anchoring part (1) and the lower anchoring part (2) are provided with slots (12). The two ends of the reinforced fixing buckle (11) are respectively inserted into the slots (12) on the corresponding sides to further press and fix the upper anchoring part (1) and the lower anchoring part (2).

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