An adaptive metatarsal prosthesis

Abstract

The present invention provides an adaptive metatarsal prosthesis, which specifically includes: a fixing cup, which is two symmetrically arranged hemispherical hollow bodies, and a fixing hole is arranged at the exact center of the fixing cup; a first rotating part, which is two symmetrically arranged hollow cylinders, and one end of the hollow cylinder is rotatably connected to the aforementioned fixing cup; a second rotating part, which is two symmetrically arranged internal meshing gears, and internal meshing helical teeth are arranged inside the second rotating part; a fixed gear, which is two symmetrically arranged external meshing gears, and external meshing helical teeth are arranged on the outer surface of the fixed gears; the external meshing helical teeth and the internal meshing helical teeth of the aforementioned second rotating part are meshed with each other; a transmission rod, which is fixedly arranged on a sleeve, and the sleeve is fixedly connected to the aforementioned fixing gear. The technical solution of the present application effectively solves the technical problem of the prosthesis not fitting well due to the growth of human bones after the metatarsal prosthesis is implanted.

Description

Technical Field

[0001] The invention relates to the field of medical instruments, and in particular to a metatarsal prosthesis. Background Art

[0002] A metatarsal prosthesis is an artificial device used to replace or reconstruct the function of the metatarsal bones (the sole of the foot). It is usually used to repair metatarsal injuries caused by trauma, disease (such as bone tumors, fractures, degenerative diseases) or deformities. Metatarsal prosthesis can help patients restore foot support and mobility and improve their quality of life.

[0003] Metatarsal prostheses can be divided into several types according to the materials and functions, including: Metal metatarsal prostheses: often made of titanium alloy, stainless steel or cobalt-chromium alloy, with high strength and durability, suitable for parts of the bones that bear more weight. Ceramic metatarsal prostheses: Ceramic materials have good biocompatibility and are usually used to reduce friction and wear of the prosthesis and reduce damage to surrounding tissues. Polymer or composite prostheses: This type of prosthesis is lighter and has elasticity close to natural bones. It is suitable for specific patients or needs and is usually used to repair part of the foot.

[0004] Metatarsal prostheses are designed to provide support and mobility to patients who have lost normal function due to disease or trauma. However, as the human skeleton grows and develops, especially during childhood and adolescence, the size and shape of the metatarsal prosthesis may no longer match the developed bone structure. This mismatch can cause several problems: When the prosthesis does not fit the bone effectively, it can cause discomfort to the patient during walking and other daily activities, which in turn affects mobility and quality of life. Ill-fitting prostheses may produce excessive stress in certain areas, increasing wear between the bone and the prosthesis, which can cause pain or injury. As the bone changes, the interaction of the prosthesis with the surrounding soft tissue and bone may also be affected, leading to rejection or soft tissue damage. Over time, patients may need to frequently adjust or replace the prosthesis to accommodate bone growth, which increases medical costs and the psychological burden on patients. Inappropriate prostheses may hinder normal bone development, cause deformities or other complications, and affect long-term bone health.

[0005] Therefore, the design of metatarsal prostheses needs to take into account the anatomical changes of the human body at different growth stages to ensure that the prosthesis can maintain good fit and functionality throughout life. Summary of the invention

[0006] The purpose of the present invention is to provide an adaptive metatarsal prosthesis to solve the technical problem of poor fit of the prosthesis due to the growth of human bones after the metatarsal prosthesis is implanted.

[0007] In order to solve the above problems, the present invention provides an adaptive metatarsal prosthesis, which specifically includes: a fixing cup, which is two symmetrically arranged hemispherical hollow bodies, and a fixing hole is arranged at the center of the fixing cup; a first rotating part, which is two symmetrically arranged hollow cylinders, and one end of the hollow cylinder is rotatably connected to the aforementioned fixing cup; a second rotating part, which is two symmetrically arranged internal meshing gears, and internal meshing helical teeth are arranged inside thereof; a fixed gear, which is two symmetrically arranged external meshing gears, and external meshing helical teeth are arranged on the outer surface thereof; the external meshing helical teeth and the internal meshing helical teeth of the aforementioned second rotating part are meshed with each other; a transmission rod, which is fixedly arranged on a sleeve, and the sleeve is fixedly connected to the aforementioned fixed gear.

[0008] Furthermore, two driven balls are arranged on the inner surface of the first rotating part.

[0009] Furthermore, a cam is disposed on the outer surface of the transmission rod, and the cam is a spherical groove track wound on the transmission rod, and the cam and the driven ball of the first rotating part are rotatably matched with each other.

[0010] Furthermore, the outer surface of the hemispherical hollow body of the fixing cup is provided with a trabecular-like structure to promote the growth of bone tissue and increase the long-term stability of the prosthesis.

[0011] Furthermore, the pitches of the external meshing helical teeth and the internal meshing helical teeth are set with different specifications, and the rotational transmission ratio of the prosthesis is changed by adjusting the pitches to adapt to the gait requirements of different patients.

[0012] Furthermore, the tooth profiles of the external meshing helical teeth and the internal meshing helical teeth are involute-arc compound tooth profiles, so as to improve the smoothness of gear meshing and transmission accuracy during rotation.

[0013] Furthermore, the inner wall of the hollow cylinder of the first rotating part is provided with a polytetrafluoroethylene coating, which has good wear resistance and chemical stability, so as to reduce the friction generated during the rotation process and improve the rotation flexibility and service life of the prosthesis.

[0014] According to the technical solution of the present invention, the fixed cup is two symmetrically arranged hemispherical hollow bodies, a fixing hole is arranged at the exact center of the fixed cup, the first rotating part is two symmetrically arranged hollow cylinders, one end of the hollow cylinder is rotatably connected to the aforementioned fixed cup, the second rotating part is two symmetrically arranged internal meshing gears, internally arranged with internal meshing helical teeth, and the fixed gear is two symmetrically arranged external meshing gears, external meshing helical teeth are arranged on the outer surface; the external meshing helical teeth and the internal meshing helical teeth of the aforementioned second rotating part are meshed with each other, the transmission rod is fixedly arranged on the sleeve, and the sleeve is fixedly connected to the aforementioned fixed gear. Two driven balls are arranged on the inner surface of the first rotating part, and a cam is arranged on the outer surface of the transmission rod, and the cam and the driven ball of the first rotating part are rotatably matched with each other. A fixed cup at one end of the metatarsal prosthesis is connected to the proximal phalanx, and a fixed cup at the other end is connected to the medial cuneiform. When the phalanx and the medial cuneiform grow, the adaptive phalanx prosthesis will be squeezed. Under the action of the squeezing force, the first rotating block is tightened inward along the cam, thereby driving the second rotating block to rotate. Under the action of the external meshing oblique teeth and the internal meshing oblique teeth, the adaptive phalanx prosthesis will stretch to both sides, thereby achieving a better adaptation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0016] Figure 1 A cross-sectional view of an adaptive metatarsal prosthesis is shown;

[0017] Figure 2 An assembly diagram of an adaptive metatarsal prosthesis is shown;

[0018] Figure 3 a cross-sectional view showing an assembly view of an adaptive metatarsal prosthesis;

[0019] Figure 4 A positive triaxial view of the second rotating part is shown;

[0020] Figure 5 A schematic diagram of the internal structure of the adaptive metatarsal prosthesis is shown;

[0021] Among them, the above-mentioned drawings include the following figure marks: 10, fixed cup; 101, fixed hole; 20, first rotating part; 201, driven ball; 30, second rotating part; 301, internal meshing helical teeth; 40, fixed gear; 401, external meshing helical teeth; 50, sleeve; 60, transmission rod; 601, cam. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0025] like Figure 1-4 As shown: an adaptive metatarsal prosthesis, comprising: a fixing cup 10, which is two symmetrically arranged hemispherical hollow bodies, and a fixing hole 101 is arranged at the exact center of the fixing cup; a first rotating part 20, which is two symmetrically arranged hollow cylinders, one end of which is rotatably connected to the fixing cup 10; a second rotating part 30, which is two symmetrically arranged internal meshing gears, and internal meshing helical teeth 301 are arranged inside; a fixing gear 40, which is two symmetrically arranged external meshing gears, and external meshing helical teeth 401 are arranged on the outer surface; the external meshing helical teeth 401 and the internal meshing helical teeth 301 of the second rotating part 30 are meshed with each other; a transmission rod 60, which is fixedly arranged on a sleeve 50, and the sleeve 50 is fixedly connected to the fixing gear 40. Two driven balls 201 are arranged on the inner surface of the first rotating part 20. A cam 601 is disposed on the outer surface of the transmission rod 60 . The cam is a spherical groove track wound on the transmission rod. The cam 601 and the driven ball 201 of the first rotating part 20 are rotatably matched with each other.

[0026] When in use, the fixing cup 10 at one end of the metatarsal prosthesis is connected to the proximal phalanx through the fixing hole 101, and the fixing cup 101 at the other end is connected to the medial cuneiform through the fixing hole 101. During the growth of the human femur, the phalanx and cuneiform on both sides of the prosthesis will apply pressure to the adaptive metatarsal prosthesis, and the pressure is transmitted to the first rotating part 20 through the fixing cup 10. When the first rotating part is subjected to pressure, the driven ball 201 inside it will move toward the middle of the prosthesis along the cam 601 on the transmission rod 60, and the first rotating part 20 will further drive the transmission rod 60 to rotate. Since the second rotating part 30 and the fixed gear 40 are provided with an internal meshing gear 301 and an external meshing gear 401, the second rotating part 30 will move to both sides, thereby pushing the first rotating part 20 outward, thereby achieving the effect of extending the prosthesis.

[0027] In order to further improve the fixation effect and overall stability, the outer surface of the hemispherical hollow body of the fixation cup is provided with a bone trabecular structure, the tooth profile of the external meshing helical teeth and the internal meshing helical teeth is an involute-arc composite tooth profile, and the inner wall of the hollow cylinder of the first rotating part is provided with a polytetrafluoroethylene coating. At the same time, in order to adapt to different human bodies and different degrees of illness, the pitch of the external meshing helical teeth and the internal meshing helical teeth is set with different specifications.

[0028] During the initial replacement, the doctor can manually adjust the size of the metatarsal prosthesis. After implantation, the rotating sleeve 50 drives the transmission rod 60 to rotate, and the fixed gear drives the second rotating part to move to both sides. At the same time, the cam on the transmission rod squeezes the first rotating part outward, thereby achieving the effect of lengthening the metatarsal prosthesis.

[0029] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0030] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein are interpreted accordingly.

[0031] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An adaptive metatarsal prosthesis, characterized in that: include: A fixing cup, wherein the fixing cup is two symmetrically arranged hemispherical hollow bodies, and a fixing hole is arranged at the center of the fixing cup; A first rotating part, wherein the first rotating part is two symmetrically arranged hollow cylinders, one end of each hollow cylinder is rotatably connected to the aforementioned fixed cup, and two driven balls are arranged on the inner surface of the first rotating part; A second rotating part, the second rotating part is two symmetrically arranged internal meshing gears, and internally arranged internal meshing helical teeth; The fixed gears are two symmetrically arranged externally meshed gears, and the outer surfaces of the fixed gears are provided with externally meshed helical teeth; the externally meshed helical teeth and the internally meshed helical teeth of the second rotating part mesh with each other; A transmission rod, wherein a cam is arranged on the outer surface of the transmission rod, wherein the cam is a spherical groove track wound on the transmission rod, wherein the cam and the driven ball of the first rotating part can rotatably cooperate with each other, and the transmission rod is fixedly arranged on a sleeve, and the sleeve is fixedly connected to the aforementioned fixed gear.

2. The metatarsal prosthesis according to claim 1, characterized in that: The outer surface of the hemispherical hollow body of the fixing cup is provided with a trabecular structure.

3. The metatarsal prosthesis according to claim 1, characterized in that: The tooth pitches of the external helical teeth and the internal helical teeth are arranged with different specifications.

4. The metatarsal prosthesis according to claim 3, characterized in that: The tooth profiles of the external meshing helical teeth and the internal meshing helical teeth are involute-arc compound tooth profiles.

5. The adaptive metatarsal prosthesis according to claim 1, characterized in that: The inner wall of the hollow cylinder of the first rotating part is provided with a polytetrafluoroethylene coating.

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