Atlantoaxial posterior lateral mass fusion cage
By designing a fusion cage that fits the atlantoaxial joint, the problem of mismatch in existing fusion cages has been solved, achieving stability and bony fusion of the atlantoaxial joint, reducing venous plexus tears and spinal cord compression, and adapting to different pathologies and patient anatomical characteristics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-03
- Publication Date
- 2026-04-07
AI Technical Summary
The lack of a fusion device specifically designed for the atlantoaxial joint in current technology makes the internal fixation device prone to loosening or breakage during surgery, and it cannot effectively reduce the compression of the spinal cord by the odontoid process.
An anatomical fusion device specifically designed for the atlantoaxial joint is designed with two elliptical arc surfaces at the insertion end having a radius ratio of 1.5-3, and the curvature is adapted to the atlantoaxial joint surface to reduce the risk of venous plexus tearing. A bone graft window is set in the longitudinal section to promote bony fusion.
It improves the stability of the atlantoaxial joint, reduces stress concentration in the internal fixation device, promotes bony fusion, alleviates spinal cord compression symptoms, and is adaptable to different pathological conditions and patient anatomical characteristics.
Smart Images
Figure CN224085510U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of medical devices, in particular to a atlantoaxial posterior lateral mass fusion cage. BACKGROUND
[0002] Atlantoaxial dislocation is a common bone structural deformity in the craniocervical junction, which is usually caused by factors such as trauma, congenital malformation, inflammation (such as rheumatoid arthritis), tumor, tuberculosis or degenerative disease. The normal anatomical relationship between the atlas and the axis is destroyed, especially when the odontoid process of the axis is displaced posteriorly, which can cause compression of the medulla oblongata and the upper cervical cord, and cause a series of neurological symptoms. This deformity can cause patients to have symptoms such as occipital and cervical pain, torticollis, limb numbness and weakness, paresthesia, double lower limb cotton feeling, chest and abdominal banding, dyspnea and swallowing disorders. These symptoms seriously affect the patient's quality of life, and if not treated in time, they may even threaten the patient's life.
[0003] Atlantoaxial posterior joint distraction reduction fusion surgery is one of the common surgical methods for treating atlantoaxial dislocation. During the surgery, the atlantoaxial fusion cage plays a crucial role. It can provide longitudinal support force for the reduced atlantoaxial joint, help maintain the mechanical balance of the atlantoaxial joint, make the stress distribution close to the normal physiological state, thereby avoiding excessive stress concentration on the internal fixation device and reducing the risk of internal fixation loosening or breaking. At the same time, the implantation of the fusion cage increases the gap of the atlantoaxial lateral mass, improves the compression of the odontoid process on the spinal cord, and helps to alleviate postoperative neurological symptoms.
[0004] Currently, there is no fusion cage specially designed for atlantoaxial joint during surgery. CONTENT OF THE UTILITY MODEL
[0005] In order to solve the problems in the related art, the present disclosure provides an atlantoaxial posterior lateral mass fusion cage.
[0006] An atlantoaxial posterior lateral mass fusion cage is provided in the present disclosure, comprising: a fusion cage body;
[0007] The fusion cage body comprises a placement end, the placement end is surrounded by two elliptical curved surfaces, the radii of the two elliptical curved surfaces in the vertical direction are in a preset ratio, and the preset ratio is 1.5-3.
[0008] According to an embodiment of the present disclosure, the preset ratio is 2.
[0009] According to an embodiment of the present disclosure, the fusion cage body further comprises an upper curved surface and a lower curved surface; wherein in the longitudinal section of the fusion cage body, the maximum chord length of the arc lines of the upper curved surface and the lower curved surface is arranged in parallel.
[0010] According to an embodiment of the present disclosure, the fusion device body further comprises an upper arc surface and a lower arc surface; wherein in a longitudinal section of the fusion device body, the extension line of the maximum chord length of the arc lines of the upper arc surface and the lower arc surface forms a preset included angle, and the preset included angle is 10-15°.
[0011] According to an embodiment of the present disclosure, the preset included angle is 10° or 15°.
[0012] According to an embodiment of the present disclosure, a bone graft window is arranged on the fusion device body.
[0013] According to an embodiment of the present disclosure, the surface of the fusion device body is provided with anti-skid lines.
[0014] According to an embodiment of the present disclosure, the shape of the fusion device body is adapted to the atlas-axis anatomical structure.
[0015] According to an embodiment of the present disclosure, the atlas-axis posterior lateral mass fusion device comprises a fusion device body; the fusion device body comprises an insertion end, and the insertion end is surrounded by two elliptical arc surfaces; the radii of the two elliptical arc surfaces in the vertical direction form a preset ratio, and the preset ratio is 1.5-3. The above technical solution provides an anatomical fusion device specially designed for atlas-axis, and by designing the curvature of the insertion end arc surface, the radius ratio of the two elliptical arc surfaces of the insertion end in the vertical direction is between 1.5-3, so as to facilitate the entry from the lower rear of the atlas-axis joint surface gap in the posterior direction, and reduce the risk of venous plexus laceration.
[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 Fig. 1 shows a front view of an atlas-axis posterior lateral mass fusion device according to an embodiment of the present disclosure.
[0018] Figure 2 Fig. 2 shows a side view of an atlas-axis posterior lateral mass fusion device according to an embodiment of the present disclosure.
[0019] Figure 3 Fig. 3 shows a top view of an atlas-axis posterior lateral mass fusion device according to an embodiment of the present disclosure.
[0020] Figure 4 Fig. 4 shows a rear view of an atlas-axis posterior lateral mass fusion device according to an embodiment of the present disclosure. DETAILED DESCRIPTION
[0021] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so as to be easily carried out by one of ordinary skill in the art. Also, portions irrelevant to the description of the exemplary embodiments are omitted in the drawings for the sake of clarity.
[0022] In the present disclosure, it is to be understood that terms such as "include" or "has" are intended to indicate that there are constituents, numbers, steps, actions, parts, or combinations thereof disclosed in the specification, and are not intended to exclude the possibility of existence or addition of one or more other constituents, numbers, steps, actions, parts, or combinations thereof.
[0023] It is additionally noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other in the case of no conflict. The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0024] Atlantoaxial posterior joint distraction reduction fusion is one of the common surgical methods for treating atlantoaxial dislocation. In the surgical process, the atlantoaxial fusion cage plays a crucial role. It can provide longitudinal support force for the reduced atlantoaxial joint, help maintain the mechanical balance of the atlantoaxial joint, make the stress distribution close to the normal physiological state, thereby avoiding excessive stress concentration on the internal fixation device and reducing the risk of internal fixation loosening or rupture. At the same time, the implantation of the fusion cage increases the gap of the atlantoaxial mass, improves the compression of the dentate process on the spinal cord, and helps to relieve postoperative neurological symptoms. At present, there is no fusion cage specially designed for atlantoaxial joint in the surgical process.
[0025] In view of the above-mentioned defects, the present disclosure provides an anatomical fusion cage specially designed for atlantoaxial joint. By designing the curvature of the placement end arc surface, the radius ratio of the two elliptical arc surfaces of the placement end in the vertical direction is between 1.5-3, so as to facilitate the entry from the rear lower part of the atlantoaxial joint surface gap, and reduce the risk of venous plexus laceration.
[0026] Figure 1 A front view of an atlantoaxial posterior mass fusion cage according to an embodiment of the present disclosure is shown. Figure 2 A side view of an atlantoaxial posterior mass fusion cage according to an embodiment of the present disclosure is shown. Figure 3 A top view of an atlantoaxial posterior mass fusion cage according to an embodiment of the present disclosure is shown. Figure 4 A rear view of an atlantoaxial posterior mass fusion cage according to an embodiment of the present disclosure is shown.
[0027] As Figures 1 to 4As shown, the atlantoaxial posterior lateral mass cage comprises a cage body 10; the cage body 10 comprises an insertion end 11, the insertion end 11 is surrounded by two elliptical curved surfaces 111, 112, the radii of the two elliptical curved surfaces 111, 112 in the vertical direction are in a preset ratio, and the preset ratio is 1.5-3.
[0028] For example, Figure 2 The horizontal direction radius ap of the middle elliptical curved surface 111 and the horizontal direction radius cp of the elliptical curved surface 112 partially overlap to form a bullet-shaped insertion end 11. The vertical direction radius ab of the elliptical curved surface 111 and the vertical direction radius cd of the elliptical curved surface 112 are in a preset ratio. The preset ratio is 1.5-3, preferably, the preset ratio is 2. In this way, the insertion end 11 is designed to enter from the lower rear of the atlantoaxial joint surface gap, reducing the risk of venous plexus laceration.
[0029] According to an embodiment of the present disclosure, the cage body 10 further comprises an upper curved surface 12 and a lower curved surface 13; wherein in the longitudinal section of the cage body 10, the extension line of the maximum chord length of the arc lines of the upper curved surface 12 and the lower curved surface 13 forms a preset included angle, and the preset included angle is 10-15°, so as to adapt to different pathological conditions and surgical needs. In one embodiment, the preset included angle is designed to be 15°, which is suitable for patients with irreducible atlantoaxial dislocation who need to correct the clinoaxial angle, and can provide stronger correction force during surgery.
[0030] For example, Figure 2 The maximum chord length of the arc line of the upper curved surface 12 is be, and the maximum chord length of the arc line of the lower curved surface 13 is df, and the extension line of the maximum chord length be and df forms a preset included angle α, and the preset included angle α is 10-15°.
[0031] In another embodiment, the maximum chord length of the arc lines of the upper curved surface 12 and the lower curved surface 13 in the longitudinal section of the cage body 10 is arranged in parallel.
[0032] For example, Figure 2 The maximum chord length of the arc line of the upper curved surface 12 is be, and the maximum chord length of the arc line of the lower curved surface 13 is df, and the maximum chord length be and df is arranged in parallel, in other words, the extension line of the maximum chord length be and df forms a preset included angle α, and the preset included angle α is 0°. The preset included angle is designed to be 0°, which is suitable for conventional atlantoaxial dislocation surgery to restore normal atlantoaxial anatomical structure.
[0033] According to an embodiment of the present disclosure, the cage body 10 is provided with a bone graft window 14, and the bone graft window 14 can be filled with autograft or allograft and other bone graft materials to accelerate the bone fusion process and promote early stability.
[0034] According to an embodiment of the present disclosure, the fusion device body 10 further comprises a rear end face 15, and two notches 151 and a round hole 152 are arranged on the rear end face 15 for connecting a holder.
[0035] According to an embodiment of the present disclosure, the surface of the fusion device body 10 is provided with anti-skid lines 16.
[0036] According to an embodiment of the present disclosure, the shape of the fusion device body 10 is adapted to the atlas-axis anatomical structure, thereby providing a better support effect.
[0037] According to an embodiment of the present disclosure, according to the needs of different patients (adults and children), the length of the atlas-axis posterior lateral mass fusion device provides two specifications of 15 mm and 12 mm to adapt to different sizes of atlas-axis joints.
[0038] The current atlas-axis posterior joint distraction reduction fusion surgery includes the following main steps:
[0039] Patient position and incision: the patient adopts a prone position and undergoes continuous skull traction. The surgery adopts a straight incision in the middle of the neck back to expose the atlas-axis bony structure.
[0040] Joint release: after exposing the atlas-axis joint, the cartilage on the atlas-axis joint surface is removed, and a distractor is used to insert into the joint space step by step to release the atlas-axis joint.
[0041] Fusion device implantation: after release, the fusion device is implanted into the atlas-axis joint space on both sides, and the fusion device provides stable longitudinal support to ensure the stability of the atlas-axis after reduction.
[0042] Internal fixation: the atlas-axis screw rod system or the occipito-cervical fixation system is used to further stabilize the state of the atlas-axis after reduction, and restore the normal physiological structure of the upper cervical spine.
[0043] Postoperative closure: after the surgery is completed, the wound is sutured layer by layer.
[0044] The atlas-axis posterior lateral mass fusion device provided by the present disclosure is applied in the fusion device implantation link.
[0045] The atlas-axis posterior lateral mass fusion device provided by the present disclosure at least achieves the following technical effects:
[0046] 1. The shape of the fusion device body is adapted to the atlas-axis anatomical structure, including the concave-convex curved surface of the upper and lower fusion device bodies and the arc design of the side surface, which ensures that the atlas-axis posterior lateral mass fusion device can perfectly fit the surface of the atlas-axis joint, and avoids the problem that the existing lower cervical or lumbar fusion device does not match the atlas-axis anatomical structure.
[0047] 2. The radius of the two elliptical arcs in the vertical direction of the insertion end is in a preset ratio, which is between 1.5 and 3, facilitating the insertion end to enter from the lower rear of the atlantoaxial joint surface gap from the posterior approach, and reducing the risk of venous plexus laceration.
[0048] 3. In the longitudinal section of the body of the fusion device, the extension of the maximum chord length of the arc lines of the upper and lower arcs forms a preset angle, which is 10-15° or 0°, to adapt to different pathological conditions.
[0049] 4. The middle part of the body of the fusion device is provided with a bone graft window, in which autologous bone or allogeneic bone and other bone graft materials can be filled to promote the bony fusion of the atlantoaxial joint, accelerate the postoperative bone fusion process, and improve the long-term stability of postoperative reduction.
[0050] 5. Two specifications of atlantoaxial posterior lateral mass fusion devices with front and rear lengths of 15mm and 12mm respectively are provided according to the anatomical characteristics of different patients, which are suitable for atlantoaxial dislocation surgery of adult and pediatric patients respectively. The multi-specification design enhances the adaptability of the fusion device, ensuring that the individual needs of different patients in surgery are met.
[0051] The above description is only the preferred embodiments of the present disclosure and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features can be replaced with the technical features disclosed in the present disclosure (but not limited to) with similar functions to form technical solutions.
Claims
1. A posterior atlantoaxial lateral mass fusion device, characterized in that, include: The fusion unit itself; The fusion device body includes an insertion end, which is surrounded by two elliptical arc surfaces. The radii of the two elliptical arc surfaces in the vertical direction are in a preset ratio, which is 1.5-3.
2. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The preset ratio is 2.
3. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The fusion device body also includes an upper arc surface and a lower arc surface; wherein, in the longitudinal section of the fusion device body, the maximum chord lengths of the arcs of the upper and lower arc surfaces are arranged in parallel.
4. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The fusion device body also includes an upper arc surface and a lower arc surface; wherein, in the longitudinal section of the fusion device body, the extension lines of the maximum chord lengths of the arcs of the upper and lower arc surfaces form a preset angle, the preset angle being 10-15°.
5. The atlantoaxial posterior lateral mass fusion device according to claim 4, characterized in that, The preset included angle is 10° or 15°.
6. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The fusion device body is provided with a bone graft window.
7. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The surface of the fusion device body is provided with anti-slip texture.
8. The atlantoaxial posterior lateral mass fusion device according to claim 1, characterized in that, The shape of the fusion device body is adapted to the anatomical structure of the atlantoaxial joint.