Restrictive movable prosthesis applied to cervical vertebra hybrid surgery

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a restrictive movable prosthesis applied to a cervical vertebra mixed operation. According to the restrictive movable prosthesis, the limiting assembly can limit the movement range between the upper plate and the lower plate, namely, the relative deflection angle of the upper plate and the lower plate is limited, and for a patient who is subjected to a cervical vertebra mixed operation, the restrictive movable prosthesis can improve the biomechanical environment of the fusion segment through restrictive movement; therefore, the early fusion of the fusion segment in the mixed operation is promoted, and the postoperative recovery effect is improved.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and specifically relates to a restrictive movable prosthesis for use in mixed cervical spine surgery. Background Technology

[0002] Anterior cervical spine hybrid surgery refers to a procedure that combines artificial cervical disc replacement with anterior cervical fusion. Over ten years of clinical research has fully demonstrated the safety and effectiveness of this procedure. However, existing artificial cervical disc prostheses are designed with simple replacement as the primary goal, and there are currently no replacement prostheses specifically designed for anterior cervical spine hybrid surgery. Furthermore, due to the interaction between replacement and fusion, a suitable range of motion in the replacement segment prosthesis is more conducive to the fusion of the fusion segment. Our previous research has also confirmed this conclusion. Therefore, it is necessary to design a novel movable prosthesis for anterior cervical spine hybrid surgery, which, by adjusting its appropriate range of motion, can better promote the fusion of the fusion segment. Summary of the Invention

[0003] This invention provides a restrictive prosthesis for use in mixed cervical spine surgery, addressing the technical problem that existing artificial cervical disc products aim to restore segmental mobility as much as possible, without considering the impact of the artificial cervical disc on the biomechanical environment and early fusion rate of the fused segment.

[0004] This invention is achieved through the following technical solution: A restrictive prosthesis for use in mixed cervical spine surgery includes an upper plate, a lower plate, and a limiting component; The upper end face of the lower plate is provided with a movable groove with a circular cross-section in the transverse direction and an arc-shaped cross-section in the longitudinal direction; The lower end face of the upper plate is provided with a movable protrusion that matches the movable groove; the upper plate is disposed on the upper end face of the lower plate through the cooperation of the movable protrusion and the movable groove. The limiting component is disposed on the upper end face of the lower plate or the lower end face of the upper plate, and is used to limit the relative deflection angle between the upper plate and the lower plate.

[0005] To better realize the present invention, further optimizations are made to the above structure. The limiting component is a ring structure, the inner diameter of the limiting component is larger than the diameter of the transverse cross-sectional shape of the movable groove, and the limiting component is coaxially disposed on the upper end surface of the lower plate or the lower end surface of the upper plate.

[0006] To better realize the present invention, the above structure is further optimized by providing at least two toothed ratchet A on the upper end face of the upper plate, and all the toothed ratchet A are arranged in the same direction.

[0007] To better realize the present invention, the above structure is further optimized. The lower end face of the lower plate is provided with two rows of parallel toothed rows, each row of toothed rows including at least two toothed ratchet B.

[0008] In addition, the present invention provides another restrictive movable prosthesis for use in mixed cervical spine surgery, which includes an upper plate, a lower plate and a limiting component; The lower end face of the upper plate is provided with a movable groove with a circular cross-section in the transverse direction and an arc-shaped cross-section in the longitudinal direction; The upper end face of the lower plate is provided with a movable protrusion that matches the movable groove; the upper plate is disposed on the upper end face of the lower plate through the cooperation of the movable protrusion and the movable groove. The limiting component is disposed on the upper end face of the lower plate or the lower end face of the upper plate, and is used to limit the relative deflection angle between the upper plate and the lower plate.

[0009] Compared with the prior art, the present invention has the following advantages: The restrictive movement prosthesis provided by this invention for use in mixed cervical spine surgery has a limiting component that restricts the range of motion between the upper and lower plates, that is, restricts the relative deflection angle between the upper and lower plates. For patients undergoing mixed cervical spine surgery, this restrictive movement prosthesis can improve the biomechanical environment of the fusion segment by restricting movement, thereby promoting early fusion of the fusion segment in mixed surgery and improving postoperative recovery. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of a restrictive movable prosthesis for use in mixed cervical spine surgery according to the present invention.

[0012] Figure 2 This is a cross-sectional view of one embodiment of a restricted movable prosthesis for mixed cervical spine surgery according to the present invention.

[0013] Figure 3 This is an exploded view of one embodiment of a restrictive movable prosthesis for mixed cervical spine surgery according to the present invention.

[0014] Figure 4 This is a cross-sectional view of another embodiment of a restricted movable prosthesis for mixed cervical spine surgery according to the present invention.

[0015] In the picture: 1. Upper plate; 11. Tooth ratchet A; 2. Lower plate; 21-toothed ratchet B; 3. Movable slot; 4. Movable protrusions; 5. Limiting components. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0017] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0019] In the embodiments of this application, such as Figures 1 to 4 As shown, the restrictive prosthesis includes an upper plate 1, a lower plate 2, and a limiting assembly 5; wherein, The upper end face of the lower plate 2 is provided with a movable groove 3 with a circular cross-section in the transverse direction and an arc-shaped cross-section in the longitudinal direction; The lower end face of the upper plate 1 is provided with a movable protrusion 4 that matches the movable groove 3. That is, the cross-sectional shape of the movable protrusion 4 is circular and the longitudinal cross-sectional shape is arc. The upper plate 1 is set on the upper end face of the lower plate 2 through the cooperation of the movable protrusion 4 and the movable groove 3, so that the upper plate 1 can move freely in the movable groove 3 of the lower plate 2. Specifically, the upper plate 1 can freely deflect around the axis of the movable groove 3 to meet the movement requirements of the replacement segment. The limiting component 5 is disposed on the upper end surface of the lower plate 2 or the lower end surface of the upper plate 1. In this embodiment, the limiting component 5 is disposed on the lower end surface of the upper plate 1. See [link to relevant documentation]. Figure 1 , Figure 2 and Figure 3 It is used to limit the relative deflection angle of the upper plate 1 and the lower plate 2. For patients undergoing mixed surgery, this restrictive prosthesis can effectively limit the range of motion of the replaced segment, improve the biomechanical environment of the fused segment, thereby promoting the early fusion of the fused segment, improving the early stability of mixed surgery, and accelerating postoperative recovery.

[0020] According to follow-up findings (see Table 1), in the three-segment hybrid surgery, when the range of motion of the artificial cervical intervertebral disc (the range of angles of deflection around the axis of the movable groove 3) was 4°-8°, the fusion rate of the artificial cervical intervertebral disc and the fusion segment at 3 months reached 45.95%, which was significantly higher than 25% for 0°-4° and 14.29% for above 8°. Furthermore, the chi-square test showed that at 3 months, there was a correlation between the range of motion of the artificial cervical intervertebral disc and the fusion rate of the artificial cervical intervertebral disc and the fusion segment. Therefore, limiting the range of motion of the restrictive prosthesis to a certain extent can further improve the early fusion rate between the restrictive prosthesis and the fusion segment.

[0021] Table 1: Statistics on the fusion rate of artificial cervical intervertebral discs and fused segments after grouping according to range of motion:

[0022] Table 2: Results of chi-square test, etc. Chi-square test (3 months) χ²=6.4921, P=0.0389 There was a significant overall correlation (P<0.05), and the grouping of range of motion affected the early fusion of the artificial cervical intervertebral disc and the fusion segment. Chi-square test (6 months) χ²=2.8214, P=0.2440 Although there were differences overall, there was no statistically significant correlation (P>0.05); therefore, the following three analyses only analyzed the situation in March. Fisher Precision Inspection P=0.0412 Verify the reliability of the chi-square results (0°-4° group fusion cases = 3, expected frequency < 5, more suitable for exact test). Bonferroni Post-incident Examination Comparison between 4°-8° and above 8°; P=0.027 There was a significant difference only between the 4°-8° group and the above 8° group (P<0.05), while there was no statistically significant difference between the 0°-4° group and the other two groups. Effect size (Cramér's V) 0.303 The association strength is medium (0.2 < Cramér's V < 0.4), and this value indicates that the influence of the activity range on early fusion is considerable. Of course, the positions of the movable groove 3 and the movable protrusion 4 can be interchanged; that is, the movable groove 3 can be placed on the lower end face of the upper plate 1, and the movable protrusion 4 can be placed on the upper end face of the lower plate 2. See [reference needed]. Figure 4 This setup still allows for the relative deflection of the upper plate 1 and the lower plate 2, thus meeting the usage requirements of this restrictive prosthesis.

[0023] It should be noted that the aforementioned mixed surgery refers to a procedure that simultaneously performs artificial cervical disc replacement and anterior cervical discectomy with interbody fusion and internal fixation. Currently, the selection of replacement and fusion segments adopts an "individualized" strategy based on the differences in degeneration of different segments. That is, relatively mild segments undergo replacement surgery, while relatively severe segments undergo fusion surgery. On the one hand, this avoids the long-term safety concerns and high costs associated with full-length replacement. On the other hand, compared to long-segment ACDF, it helps maintain a more physiologically-like overall biomechanical environment of the cervical spine by preserving the mobility of some segments, thereby theoretically reducing stress concentration and compensatory overactivity in adjacent segments.

[0024] In some embodiments, the limiting component 5 described above is a ring-shaped structure, and the inner diameter of the limiting component 5 is larger than the diameter of the transverse cross-sectional shape of the movable groove 3. See [reference needed]. Figure 2 , Figure 3 and Figure 4 The limiting component 5 is coaxially disposed on the upper end face of the lower plate 2 or the lower end face of the upper plate 1; When the upper plate 1 deflects around the axis of the movable groove 3, the limiting component 5 can limit the maximum deflection angle of the upper plate 1 to limit the relative deflection angle of the upper plate 1 and the lower plate 2, thereby better promoting the fusion of the restricted movable prosthesis with the fusion segment.

[0025] Preferably, according to the contents of Tables 1 and 2 above, the relative deflection angle of the upper plate 1 and the lower plate 2 is limited to less than 8°, so as to improve the fusion effect of the restricted movable prosthesis and the fusion segment.

[0026] In some embodiments, the upper end face of the upper plate 1 is provided with at least two toothed ratchet A11s, all of which are arranged in the same direction; the lower end face of the lower plate 2 is provided with two rows of parallel toothed rows, each row including at least two toothed ratchet B21s, see [reference]. Figures 1 to 4 .

[0027] Tooth spines A11 and B21 can embed into the endplates of the upper and lower vertebral bodies, eventually forming plate-bone integration with the upper and lower vertebral bodies to maintain overall stability.

[0028] It is worth noting that the fusion of fused segments can be determined in the following ways: 1. Continuous bone bridge formation was observed on sagittal or coronal CT scans of the cervical spine.

[0029] 2. The distance between the spinous processes of the superior and inferior vertebrae measured on a dynamic cervical spine X-ray is <1mm.

[0030] When any of the above conditions are met in a fusion segment, it is considered that the current fusion segment has been fused. For multiple fusion segments, only when all fusion segments meet the above fusion criteria is it considered that the entire fusion has been completed; otherwise, they are considered that the fusion has not been complete.

[0031] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A restrictive prosthesis for use in mixed cervical spine surgery, characterized in that: It includes an upper plate (1), a lower plate (2), and a limiting component (5); The upper end face of the lower plate (2) is provided with a movable groove (3) with a circular cross-section in the transverse direction and an arc-shaped cross-section in the longitudinal direction. The lower end face of the upper plate (1) is provided with a movable protrusion (4) that matches the movable groove (3); the upper plate (1) is provided on the upper end face of the lower plate (2) through the cooperation of the movable protrusion (4) and the movable groove (3); The limiting component (5) is disposed on the upper end face of the lower plate (2) or the lower end face of the upper plate (1) to limit the relative deflection angle of the upper plate (1) and the lower plate (2).

2. The restrictive prosthesis for cervical spine mixed surgery according to claim 1, characterized in that: The limiting component (5) is a ring structure. The inner diameter of the limiting component (5) is larger than the diameter of the transverse cross-section of the movable groove (3). The limiting component (5) is coaxially arranged on the upper end face of the lower plate (2) or the lower end face of the upper plate (1).

3. The restrictive prosthesis for cervical spine mixed surgery according to claim 1 or 2, characterized in that: The upper end face of the upper plate (1) is provided with at least two toothed ratchet A (11), and all the toothed ratchet A (11) are arranged in the same direction.

4. The restrictive prosthesis for cervical spine mixed surgery according to claim 3, characterized in that: The lower end face of the lower plate (2) is provided with two rows of parallel toothed rows, each row of toothed rows including at least two toothed ratchet B (21).

5. A restrictive prosthesis for use in mixed cervical spine surgery, characterized in that: It includes an upper plate (1), a lower plate (2), and a limiting component (5); The lower end face of the upper plate (1) is provided with a movable groove (3) with a circular cross-section in the transverse direction and an arc-shaped cross-section in the longitudinal direction. The upper end face of the lower plate (2) is provided with a movable protrusion (4) that matches the movable groove (3); the upper plate (1) is provided on the upper end face of the lower plate (2) through the cooperation of the movable protrusion (4) and the movable groove (3); The limiting component (5) is disposed on the upper end face of the lower plate (2) or the lower end face of the upper plate (1) to limit the relative deflection angle of the upper plate (1) and the lower plate (2).

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