A 3D printed ankle joint system prosthesis

Abstract

The present invention provides a 3D printed ankle joint system prosthesis, which includes a titanium alloy talar prosthesis, a cobalt-chromium-molybdenum talar prosthesis, a polyethylene pad, and a distal tibial prosthesis. A matching structure is provided on the top of the titanium alloy talar prosthesis; a bone screw hole is also provided on the titanium alloy talar prosthesis, and a calcaneal fixing hole is provided on the rear end convex part of the titanium alloy talar prosthesis; a microporous structure is provided at the bottom of the titanium alloy talar prosthesis; a fixing structure is provided at the bottom of the cobalt-chromium-molybdenum talar prosthesis; the top of the cobalt-chromium-molybdenum talar prosthesis has an installation opening, and the bottom of the installation opening is provided with a joint sliding surface; the bottom of the polyethylene pad is limited in the installation opening, and the bottom surface of the polyethylene pad is a joint surface; the distal tibial prosthesis is connected to the polyethylene pad, and a locking nail bone plate and an intramedullary nail are provided on the top of the distal tibial prosthesis; and a microporous structure is provided on the distal tibial prosthesis. The present invention can not only achieve the replacement of large-segment bone defects in the ankle joint and restore the range of motion of the ankle joint, but also achieve bone ingrowth and achieve long-term stability of the prosthesis.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a 3D printed ankle joint system prosthesis. Background Art

[0002] Bone defects in the ankle joint caused by arthritis, trauma or tumors can cause serious functional impairment in patients, long-term pain and poor quality of life. Currently, the main treatments for ankle dysfunction are conservative treatment and surgical treatment. Surgical treatment includes joint-preserving treatment and non-joint-preserving treatment. Joint-preserving treatment includes osteotomy to correct force alignment, joint cavity cleaning, joint traction machine joint stabilization surgery, etc. Non-joint-preserving treatment includes joint fusion and joint replacement. The only way to treat joint defects is ankle replacement.

[0003] Ankle joint defects will cause loss of joint surface, so joint replacement is the only option. The indications for ankle replacement prostheses currently on the market are as follows: low functional requirements for the prosthesis; patients over 50 years old; suitable for rheumatoid patients. Contraindications include: severe geometric defects in the ankle joint; severe osteoporosis or osteonecrosis; foot infection; vascular disease or severe neurological disease; ligament instability and foot deformity that affects the position.

[0004] In summary, there is currently no suitable prosthesis to solve ankle bone defect conditions, especially large bone defect areas, including large bone defects in the talus and distal tibia. Summary of the invention

[0005] The purpose of the present invention is to provide a 3D printed ankle joint system prosthesis to solve the above-mentioned technical problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A 3D printed ankle joint system prosthesis, comprising a titanium alloy talar prosthesis, a cobalt-chromium-molybdenum talar prosthesis, a polyethylene pad, and a distal tibial prosthesis, wherein the top of the titanium alloy talar prosthesis is provided with a matching structure for connecting with the cobalt-chromium-molybdenum talar prosthesis, and the front and rear sides of the matching structure are provided with limited surfaces; the titanium alloy talar prosthesis is also provided with a bone screw hole, the rear side of the titanium alloy talar prosthesis has a convex portion, and the convex portion is provided with a calcaneal fixation hole for suturing; the bottom of the titanium alloy talar prosthesis is provided with a microporous structure suitable for bone ingrowth; the bottom of the cobalt-chromium-molybdenum talar prosthesis is provided with two ridges which are respectively connected to the matching structure and the limiting surface. Adaptive fixing structure and matching surface; the top of the cobalt-chromium-molybdenum talar prosthesis has a mounting opening, and the bottom of the mounting opening is provided with a joint sliding surface; the bottom of the polyethylene pad is limited in the mounting opening, and the bottom surface of the polyethylene pad is a joint surface that slides with the joint sliding surface; the bottom of the distal tibial prosthesis is connected to the top of the polyethylene pad, and the top of the distal tibial prosthesis is provided with a locking nail plate and an intramedullary nail, the locking nail plate is provided with a locking nail hole, and the intramedullary nail is provided with a nail hole opposite to the locking nail hole; the area on the distal tibial prosthesis for contacting the bone is provided with a microporous structure suitable for bone ingrowth.

[0008] Preferably, the matching structure is a conical hole and a circular hole arranged oppositely, the diameter of the upper end of the conical hole is larger than the diameter of the lower end of the conical hole; the cobalt fixing structure is a frustum of a cone and a cylinder, the frustum of a cone matches with the conical hole, and the cylinder matches with the circular hole.

[0009] Preferably, the bottom of the distal tibial prosthesis is snap-connected to the top of the polyethylene pad.

[0010] Preferably, a groove is provided at the bottom of the distal tibial prosthesis, and a clamping groove is provided on the inner wall of the groove; the top of the polyethylene pad is used to extend into the groove, and a limiting protrusion for cooperating with the clamping groove is provided on the outer wall of the top of the polyethylene pad.

[0011] Preferably, a side of the limiting protrusion away from the joint surface is an inclined surface.

[0012] Preferably, anti-slip limit grooves are arranged on the inner walls on both sides of the installation opening; anti-slip wings are arranged on both sides of the bottom of the polyethylene pad, and the anti-slip wings are clearance-matched with the anti-slip limit grooves.

[0013] Preferably, the outer surface of the upper side wall of the anti-slip limiting groove is an arc-shaped surface.

[0014] Preferably, the front and rear planes of the bottom of the polyethylene pad are both limiting inclined surfaces.

[0015] Preferably, the average pore size of the microporous structure is 500-700 μm, and the porosity is 60-80%.

[0016] Preferably, the distal tibial prosthesis is made of titanium alloy material.

[0017] The beneficial effects of the present invention are:

[0018] The 3D printed ankle joint system prosthesis of the present invention has a titanium alloy talar prosthesis and a cobalt-chromium-molybdenum talar prosthesis connected by a matching structure and a fixing structure, a top of a polyethylene pad is connected to a distal tibial prosthesis, and a bottom of the polyethylene pad is limited in an installation opening of the cobalt-chromium-molybdenum talar prosthesis. Through the sliding cooperation between the joint sliding surface of the cobalt-chromium-molybdenum talar prosthesis and the joint surface of the polyethylene pad, plantar flexion of the ankle joint can be achieved, that is, the range of motion of the ankle joint is achieved, thereby better achieving ankle replacement for patients with ankle bone defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0020] Figure 1 A schematic diagram of a 3D printed ankle joint system prosthesis provided by an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a titanium alloy talar prosthesis provided in an embodiment of the present invention;

[0022] Figure 3 Another schematic diagram of a titanium alloy talar prosthesis provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of a cobalt-chromium-molybdenum talar prosthesis provided in an embodiment of the present invention;

[0024] Figure 5 A schematic diagram of a polyethylene mat provided in an embodiment of the present invention;

[0025] Figure 6 A schematic diagram of a distal tibial prosthesis provided by an embodiment of the present invention;

[0026] Figure 7 Another schematic diagram of a distal tibial prosthesis provided by an embodiment of the present invention.

[0027] Markings in the accompanying drawings:

[0028] 1. Titanium alloy talar prosthesis 1-1, bone screw hole 1-2, conical hole 1-3, round hole

[0029] 1-4, limiting surface 1-5, calcaneal fixation hole 1-6, microporous structure

[0030] 2. Cobalt-chromium-molybdenum talar prosthesis 2-1, cone 2-2, cylinder 2-3, joint sliding surface

[0031] 2-4, anti-drop limit groove 2-5, arc surface 3, polyethylene pad 3-1, top

[0032] 3-2, limit protrusion 3-3, anti-drop wing 3-4, limit inclined surface 3-5, joint surface

[0033] 4. Distal tibial prosthesis 4-1, locking plate 4-2, intramedullary nail

[0034] 4-3, microporous structure 4-4, groove 4-5, nail hole 4-6, nail hole DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the solution will be further described in detail below in conjunction with specific embodiments.

[0036] like Figures 1 to 7 As shown, an embodiment of the present invention provides a 3D printed ankle joint system prosthesis, which includes a titanium alloy talar prosthesis 1, a cobalt-chromium-molybdenum talar prosthesis 2, a polyethylene pad 3, and a distal tibial prosthesis 4. The top of the titanium alloy talar prosthesis is provided with a matching structure, and limited surfaces 1-4 are provided on both sides of the matching structure; a bone screw hole 1-1 is also provided on the titanium alloy talar prosthesis, and the rear side of the titanium alloy talar prosthesis has a convex portion, and a calcaneal fixing hole 1-5 is provided on the convex portion; a microporous structure 1-6 is provided on the bottom of the titanium alloy talar prosthesis; the bottom of the cobalt-chromium-molybdenum talar prosthesis 2 is provided with respectively adapted to the matching structure and the limiting surface Fixing structure and mating surface; the top of the cobalt-chromium-molybdenum talar prosthesis has a mounting opening, and the bottom of the mounting opening is provided with a joint sliding surface 2-3; the bottom of the polyethylene pad is limited in the mounting opening, and the bottom surface of the polyethylene pad is a joint surface 3-5 that slidably cooperates with the joint sliding surface; the bottom of the distal tibial prosthesis is connected to the top of the polyethylene pad, and the top of the distal tibial prosthesis is provided with a locking nail plate 4-1 and an intramedullary nail 4-2, and the locking nail plate and the intramedullary nail are respectively provided with locking nail holes 4-5 and nail holes 4-6; the connection between the distal tibial prosthesis and the intramedullary nail is provided with a microporous structure 4-3 suitable for bone ingrowth.

[0037] The 3D printed ankle joint system prosthesis provided by the embodiment of the present invention has a titanium alloy talar prosthesis 1 and a cobalt-chromium-molybdenum talar prosthesis 2 connected by a matching structure and a fixing structure, the top of the polyethylene pad is connected to the distal tibial prosthesis 4, and the bottom of the polyethylene pad 3 is limited in the installation opening of the cobalt-chromium-molybdenum talar prosthesis. Through the sliding cooperation between the joint sliding surface of the cobalt-chromium-molybdenum talar prosthesis and the joint surface of the polyethylene pad, plantar flexion movement of the ankle joint can be achieved, that is, the range of motion of the ankle joint is achieved, thereby better achieving ankle replacement of patients with ankle bone defects; the pore size of the microporous structure is 500-700μm on average, and the porosity is 60-80%, which is conducive to bone ingrowth and can achieve long-term stability of the prosthesis.

[0038] Furthermore, the matching structure is a conical hole 1-2 and a circular hole 1-3 that are arranged opposite to each other, and the diameter of the upper end of the conical hole is greater than the diameter of the lower end of the conical hole; the fixed structure is a truncated cone 2-1 and a cylinder 2-2, and the truncated cone matches the conical hole, and the cylinder matches the circular hole. By adopting this scheme, a tight anti-rotation fit between the titanium alloy talar prosthesis and the cobalt-chromium-molybdenum talar prosthesis is achieved. The tight cone fit between the two is achieved by the cooperation of the truncated cone 2-1 and the conical hole 1-2, ensuring that the titanium alloy talar prosthesis 1 and the cobalt-chromium-molybdenum talar prosthesis 2 will not separate. At the same time, the cooperation of the cylinder 2-2 and the circular hole 1-3 can prevent the titanium alloy talar prosthesis 1 and the cobalt-chromium-molybdenum talar prosthesis 2 from relative rotation. It can be understood that the connection between the titanium alloy talar prosthesis 1 and the cobalt-chromium-molybdenum talar prosthesis 2 can also be achieved by other structures with anti-rotation and stable connection.

[0039] Specifically, the bottom of the distal tibial prosthesis 4 is snap-connected to the top of the polyethylene pad 3 .

[0040] like Figure 7 As shown, the bottom of the distal tibial prosthesis is provided with a groove 4-4, and the inner wall of the groove 4-4 is provided with a slot; the top of the polyethylene pad 3 is used to extend into the groove, and the outer wall of the top of the polyethylene pad is provided with a limiting protrusion 3-2 for matching with the slot, so that the polyethylene pad can be better prevented from falling out of the distal tibial prosthesis, ensuring the stability of the ankle joint system prosthesis. The groove can be preferably a rectangular groove, and in this case, the four inner walls of the groove can be provided with slots, so as to prevent relative rotation during movement.

[0041] Preferably, the side of the limiting protrusion 3-2 away from the articular surface is an inclined surface, so as to facilitate the installation between the polyethylene pad and the distal tibial prosthesis. It can be understood that the articular surface is adapted to the joint sliding surface.

[0042] Furthermore, anti-slip limit grooves 2-4 are relatively arranged on the inner walls on both sides of the installation opening; anti-slip wings 3-3 are arranged on both sides of the bottom of the polyethylene pad, and the anti-slip wings are matched with the anti-slip limit grooves, so that the anti-slip wings can be limited by the side walls of the anti-slip limit grooves to prevent the polyethylene pad from falling out of the installation opening. It can be understood that the joint sliding surface of the cobalt-chromium-molybdenum talar prosthesis and the joint surface of the polyethylene pad together form a joint activity interface that conforms to the natural ankle plantar flexion movement trajectory of normal people; wherein the anti-slip limit grooves 2-4 can prevent the joint surface from being dislocated, and during normal movement, the anti-slip limit grooves do not participate in the contact, and when inversion or eversion occurs, they play a role of limiting, and at the same time, the limiting inclined surface 3-4 prevents excessive plantar flexion movement from occurring at the joint activity interface.

[0043] Specifically, the outer surface of the upper side wall of the anti-dislocation limit groove is an arc surface 2-5, so that the gap consistency can be maintained during joint movement. It can be understood that the connection between the cobalt-chromium-molybdenum talar prosthesis 2 and the polyethylene pad 3 can also be achieved through other structures with a certain degree of internal and external rotation and internal and external eversion activities; the microporous structure can facilitate the growth of bone tissue to ensure the long-term stability of the ankle joint system prosthesis after implantation into the human body.

[0044] Preferably, the front and rear planes of the bottom of the polyethylene pad are both limiting inclined surfaces 3-4, so that the joint surface can be limited on the joint sliding surface, that is, the joint surface 3-5 at the bottom of the polyethylene pad has the same curvature as the joint sliding surface 2-3, which can ensure the contact area of ​​the joint surface and reduce contact stress. It can be understood that the cobalt-chromium-molybdenum talar prosthesis 2 is made of cobalt-chromium-molybdenum material.

[0045] Specifically, the average pore size of the microporous structure is 500-700 μm, and the porosity is 60-80%.

[0046] Preferably, the distal tibial prosthesis 4 is made of a titanium alloy material. The titanium alloy talar prosthesis is also made of a titanium alloy material, which can be processed by additive manufacturing and machined to ensure the matching size. It is understandable that the distal tibial prosthesis, the intramedullary nail 4-2, and the locking nail plate 4-1 can be an integrated structure to achieve stable fixation with the bone defect area, and at the same time, the locking nail hole 4-5 on the locking nail plate cooperates with the guide sleeve frequently used in clinical practice to ensure that the locking screw can correctly pass through the intramedullary nail channel during surgery.

[0047] The structure of the 3D printed ankle joint system prosthesis provided by the embodiment of the present invention can be customized according to the patient's design and combined with additive manufacturing. The geometric shapes of the titanium alloy talar prosthesis 1, the cobalt-chromium-molybdenum talar prosthesis 2, the polyethylene pad 3 and the distal tibial prosthesis 4 can be customized according to different patients; the geometric shape of the ankle joint system prosthesis is matched with the bone shape; the distal tibial prosthesis and the retained tibia can achieve bone geometry matching and restore the tibial morphology and mechanical structure; the titanium alloy talar prosthesis matches the retained foot bone structure and can restore the foot's geometry and mechanical structure. The cobalt-chromium-molybdenum talar prosthesis and the polyethylene pad realize the range of motion of the ankle joint, and the cobalt-chromium-molybdenum joint surface of the polyethylene can be used to ensure low wear. At the same time, in the absence of ligaments, the activity of the joint can be limited, and dislocation due to excessive activity will not be caused. The present invention can not only better achieve the replacement of large-segment bone defects in the ankle joint and restore the range of motion of the ankle joint, but also achieve bone ingrowth and achieve long-term stability of the prosthesis.

[0048] The above are only preferred embodiments of the present invention. It should be pointed out that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, after reading the contents of the present invention, relevant technical personnel in the field may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A 3D printed ankle joint system prosthesis, characterized in that: It includes a titanium alloy talar prosthesis, a cobalt-chromium-molybdenum talar prosthesis, a polyethylene pad, and a distal tibial prosthesis. The top of the titanium alloy talar prosthesis is provided with a matching structure for connecting with the cobalt-chromium-molybdenum talar prosthesis, and the front and rear sides of the matching structure are provided with limited surfaces; the titanium alloy talar prosthesis is also provided with a bone screw hole, the rear side of the titanium alloy talar prosthesis has a convex part, and the convex part is provided with a calcaneal fixing hole for suturing; the bottom of the titanium alloy talar prosthesis is provided with a microporous structure suitable for bone ingrowth; the bottom of the cobalt-chromium-molybdenum talar prosthesis is provided with a fixing structure respectively matched with the matching structure and the limiting surface and a mating surface; the top of the cobalt-chromium-molybdenum talar prosthesis has a mounting opening, and the bottom of the mounting opening is provided with a joint sliding surface; the bottom of the polyethylene pad is limited in the mounting opening, and the bottom surface of the polyethylene pad is a joint surface that slidably matches with the joint sliding surface; the bottom of the distal tibial prosthesis is connected to the top of the polyethylene pad, and the top of the distal tibial prosthesis is provided with a locking nail plate and an intramedullary nail, the locking nail plate is provided with a locking nail hole, and the intramedullary nail is provided with a nail hole opposite to the locking nail hole; the area on the distal tibial prosthesis for contacting with the bone is provided with a microporous structure suitable for bone ingrowth; The bottom of the distal tibial prosthesis is snap-connected with the top of the polyethylene pad; Anti-dropout limiting grooves are arranged on the inner walls on both sides of the installation opening; anti-dropout wings are arranged on both sides of the bottom of the polyethylene pad, and the anti-dropout wings are clearance-matched with the anti-dropout limiting grooves.

2. The 3D printed ankle joint system prosthesis according to claim 1, characterized in that: The matching structure is a conical hole and a circular hole arranged opposite to each other, and the diameter of the upper end of the conical hole is larger than the diameter of the lower end of the conical hole; the fixed structure is a frustum and a cylinder, and the frustum matches with the conical hole, and the cylinder matches with the circular hole.

3. The 3D printed ankle joint system prosthesis according to claim 1, characterized in that: The bottom of the distal tibial prosthesis is provided with a groove, and the inner wall of the groove is provided with a clamping groove; the top of the polyethylene pad is used to extend into the groove, and the outer wall of the top of the polyethylene pad is provided with a limiting protrusion for matching with the clamping groove.

4. The 3D printed ankle joint system prosthesis according to claim 3, characterized in that: A side of the limiting protrusion away from the joint surface is an inclined surface.

5. The 3D printed ankle joint system prosthesis according to claim 1, characterized in that: The outer surface of the upper side wall of the anti-slip limiting groove is an arc-shaped surface.

6. The 3D printed ankle joint system prosthesis according to claim 1, characterized in that: The front and rear planes of the bottom of the polyethylene pad are both limiting inclined surfaces.

7. The 3D printed ankle joint system prosthesis according to claim 1, characterized in that: The average pore size of the microporous structure is 500-700 μm, and the porosity is 60-80%.

8. The 3D printed ankle joint system prosthesis according to any one of claims 1 to 7, characterized in that: The distal tibial prosthesis is made of titanium alloy material.

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