A partial replacement trapezium prosthesis and a manufacturing method thereof

Abstract

A partial trapezium replacement prosthesis and a manufacturing method thereof, the prosthesis comprises a prosthesis body, wherein the palm side, the dorsal side and the radial side of the body are provided with arc-shaped connecting holes, the arc-shaped cylindrical holes are arranged obliquely with the bottom surface of the body, the proximal end of the central axis of the body is provided with a connecting column integrally formed with the body, and the side of the prosthesis body close to the first metacarpal bone has an arc surface that cooperates with the first metacarpal bone. The manufacturing method comprises performing wrist CT scans on healthy volunteers and patients respectively, performing three-dimensional reconstruction using medical software, performing simulated cutting on the reconstructed trapezium model, scaling the trapezium model remaining after the removal of the healthy volunteer in equal proportions to match the size and curved surface of the base joint surface of the first metacarpal bone of the patient, and obtaining the trapezium prosthesis by 3D printing. The present invention can partially replace part of the trapezium in hand osteoarthritis, can well preserve the stability of the wrist joint structure, prevent the first metacarpal bone from settling, relieve joint pain, increase joint activity, and has a good clinical prospect.

Description

Technical Field

[0001] The invention relates to the field of medical supplies, in particular to a partial replacement trapezium prosthesis and a manufacturing method thereof. Background Art

[0002] Osteoarthritis is one of the common diseases in the middle-aged and elderly. The most common site of osteoarthritis in the hand is the first carpometacarpal joint. According to statistics, up to 8% of men and 25% of women over the age of 50 suffer from degenerative arthritis of the thumb carpometacarpal joint (CMC). The imaging manifestations of CMC arthritis are mainly narrow joint space, marginal bone sclerosis and bone proliferation; the main clinical manifestations are pain and fatigue in the first carpometacarpal joint. In severe cases, joint subluxation, reduced range of motion or stiffness occur, which leads to reduced range of motion of the thumb, especially decreased grip and pinch strength.

[0003] For the above-mentioned CMC diseases, when drug treatment is ineffective, surgical intervention is required. Depending on the severity of the disease, in the past 30 years, there have been many studies on the surgical methods of CMC arthritis at home and abroad, mainly based on the different stages of disease progression, including partial or complete resection of the trapezium with or without loop plate fixation, partial or complete resection of the trapezium with or without pseudoarthrosis molding, tendon packing, joint replacement, joint fusion, decellularized matrix filling, etc.

[0004] However, the above surgical methods have their own disadvantages: the use of silicone prosthesis filling technology can cause complications such as periarticular synovitis and prosthesis detachment after surgery. There is a certain degree of fusion failure after CMC fusion surgery, and the postoperative non-union rate can reach 13%. In addition, elderly patients rarely have isolated first carpometacarpal arthritis, and there is a risk of scaphoid and trapezium osteoarthritis after fusion. The gap left after trapezium resection poses a potential risk for the sinking of the first metacarpal bone, further affecting the stability of the joint structure after surgery. Other studies have shown that trapezium resection can cause distal instability of the scaphoid bone, leading to secondary non-separable dorsal insertion segment wrist instability. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a partial replacement trapezium prosthesis and a manufacturing method thereof to solve the problems raised in the above technical background.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A partial trapezium replacement prosthesis comprises a prosthesis body, wherein the palm side, dorsal side and radial side of the prosthesis body are respectively provided with arcuate cylindrical holes, wherein the arcuate cylindrical holes are inclined to the bottom surface of the prosthesis body, a connecting column integrally formed with the prosthesis body is provided at the proximal end of the central axis of the prosthesis body, and the palm side of the prosthesis body has an arcuate surface cooperating with the first metacarpal bone.

[0008] Furthermore, the connecting column is in a rectangular parallelepiped shape, with a length of 5 mm and a bottom area of ​​4 mm*4 mm.

[0009] Furthermore, the arc-shaped cylindrical hole has a depth of 1 mm and a diameter of 0.5 mm.

[0010] Furthermore, the prosthesis body is made of hydrogel material.

[0011] Furthermore, the inclination angle between the arc-shaped cylindrical hole and the bottom surface of the prosthesis body is 45°

[0012] A method for manufacturing a partially replaced trapezium prosthesis, the manufacturing method comprising the following steps:

[0013] S1. Perform wrist CT scans on healthy volunteers and patients, and import the scanned imaging data into medical software to reconstruct a complete trapezium model;

[0014] S2. Perform simulated cutting on the reconstructed trapezium model of a healthy volunteer to determine the best cutting path and remove the proximal 3 / 4 along the vertical direction of the central axis of the trapezium model;

[0015] S3, simulate cutting on the reconstructed trapezium model of the patient, determine the best cutting path, and remove the distal 1 / 4 along the vertical direction of the central axis of the trapezium model;

[0016] S4, replacing the 1 / 4 trapezium model of the patient with the 1 / 4 trapezium model remaining after resection of the healthy volunteer, and then scaling the 1 / 4 trapezium model of the healthy volunteer with medical software to match the size and surface of the articular surface of the base of the first metacarpal bone of the patient;

[0017] S5. Design a connecting column at the proximal end of the central axis of the matched 1 / 4 trapezium model;

[0018] S6. Design arc-shaped cylindrical holes on the palmar, dorsal and radial sides of the matched 1 / 4 trapezium model;

[0019] S7. Use 3D printing to print out the designed simulation model to obtain a partial replacement trapezium prosthesis.

[0020] Furthermore, in step S1, the medical software is Mimics16.0.

[0021] The beneficial effects of the present invention are as follows: the present invention can partially replace part of the trapezium in hand osteoarthritis, and can well match the size and curved surface of the base articular surface of the patient's first metacarpal bone, thereby well preserving the stability of the wrist joint structure, preventing the first metacarpal bone from settling, alleviating joint pain, and increasing joint activity. Furthermore, the present invention can form a stable fixed relationship with the patient's trapezium, is not easy to slip, and has a good clinical prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the back structure of the prosthesis body of the present invention;

[0023] Figure 2 It is a schematic diagram of the palmar structure of the prosthesis body of the present invention;

[0024] Figure 3 is a side view of the prosthesis body of the present invention;

[0025] Figure 4 It is a schematic diagram of the connection between the prosthesis of the present invention and the trapezium.

[0026] In the figure, 1-prosthesis body, 2-arc cylindrical hole, 3-connecting column, 4-arc surface, 5-trapezium, 6-first metacarpal bone. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated. Example

[0029] A partial replacement trapezium prosthesis, see Appendix Figure 1 -Attached Figure 3As shown, the prosthesis includes a prosthesis body 1, and the palm side, dorsal side and radial side of the prosthesis body 1 are respectively provided with arc-shaped cylindrical holes 2, and the arc-shaped cylindrical holes 2 are inclined to the bottom surface of the prosthesis body 1. The proximal end of the central axis of the prosthesis body 1 is provided with a connecting column 3 integrally formed with the prosthesis body, and the palm side of the prosthesis body 1 has an arc surface 4 that cooperates with the first metacarpal bone.

[0030] In the above embodiment, preferably, the connecting column 3 is in a rectangular parallelepiped shape with a length of 5 mm and a bottom area of ​​4 mm*4 mm.

[0031] In the above embodiment, preferably, the arc-shaped cylindrical hole 2 has a depth of 1 mm and a diameter of 0.5 mm.

[0032] In the above embodiment, preferably, the prosthesis body 1 is made of hydrogel material.

[0033] In the above embodiment, it is most preferred that the inclination angle between the arc-shaped cylindrical hole 2 and the bottom surface of the prosthesis body 1 is 45°.

[0034] A method for manufacturing a partially replaced trapezium prosthesis, the manufacturing method comprising the following steps:

[0035] S1. Perform wrist CT scans on healthy volunteers and patients, and import the scanned imaging data into medical software to reconstruct a complete trapezium model;

[0036] S2. Perform simulated cutting on the reconstructed trapezium model of a healthy volunteer to determine the best cutting path and remove the proximal 3 / 4 along the vertical direction of the central axis of the trapezium model;

[0037] S3, simulate cutting on the reconstructed trapezium model of the patient, determine the best cutting path, and remove the distal 1 / 4 along the vertical direction of the central axis of the trapezium model;

[0038] S4, replacing the 1 / 4 trapezium model of the patient with the 1 / 4 trapezium model remaining after the resection of the healthy volunteer, and then scaling the 1 / 4 trapezium model of the healthy volunteer with the medical software to match the size and surface of the basal articular surface of the first metacarpal bone 6 of the patient;

[0039] S5. Design a connecting column 3 at the proximal end of the central axis of the matched 1 / 4 trapezium model;

[0040] S6. Design 2 arc-shaped cylindrical holes on the palmar, dorsal and radial sides of the matched 1 / 4 trapezium model;

[0041] S7. Use 3D printing to print out the designed simulation model to obtain a partial replacement trapezium prosthesis.

[0042] In the above embodiment, preferably, in step S1, the medical software is Mimics16.0.

[0043] Patients undergoing trapezium replacement should refer to the attached Figure 4 As shown, according to the cutting path in the medical software, the distal 1 / 4 is cut off in the vertical direction along the central axis of the trapezium 5, and then a mounting groove (not shown in the figure) matching the connecting column is designed on the incision surface of the remaining 3 / 4 of the trapezium 5 using surgical tools, and then the prosthesis body 1 is installed in the mounting groove (not shown in the figure) using the connecting column 3, and finally the titanium tube is installed in the arc cylindrical hole 2, and the ligament and joint capsule between the prosthesis body 1 and the first metacarpal bone 6 are sutured using the titanium tube and tendon sutures. In the present invention, the arc cylindrical hole 2 is inclined to the bottom surface of the prosthesis body 1, and the preferred inclination angle is 45°. In the process of suturing the ligament and the joint capsule, the suturing tool can pass through the prosthesis body 1 through the arc cylindrical hole 2, so as to facilitate the fixation of the prosthesis body 1 to the patient's trapezium 5.

[0044] It is necessary to explain the above embodiments that, since the palm side of the prosthesis provided by the present invention has an arc surface 4 that cooperates with the first metacarpal bone 6, it can be well matched with the size and curve of the basal articular surface of the patient's first metacarpal bone 6, thereby being able to well preserve the stability of the wrist joint structure, prevent the first metacarpal bone 6 from settling, reduce joint pain, and increase joint activity. Furthermore, the present invention is provided with a connecting column 3, which enables the prosthesis body 1 to stably cooperate with the patient's trapezium 5 after surgery and is not easy to slip. Finally, the present invention is provided with arc-shaped cylindrical holes 2 on the palm side, dorsal side and radial side of the prosthesis body 1, respectively, and a titanium tube can be installed in the arc-shaped cylindrical hole 2 to facilitate the suturing of the ligament and joint capsule between the prosthesis body 1 and the first metacarpal bone 6.

[0045] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a partially replaced trapezium prosthesis, characterized in that: The prosthesis comprises a prosthesis body, wherein the palm side, the dorsal side and the radial side of the prosthesis body are respectively provided with arc-shaped cylindrical holes, the arc-shaped cylindrical holes are arranged obliquely with the bottom surface of the prosthesis body, the proximal end of the central axis of the prosthesis body is provided with a connecting column integrally formed with the prosthesis body, the side of the prosthesis body near the first metacarpal bone has an arc surface that cooperates with the first metacarpal bone, the connecting column is in the shape of a rectangular parallelepiped, the length is 5 mm, the bottom surface area is 4 mm * 4 mm, the depth of the arc-shaped cylindrical hole is 1 mm, the diameter is 0.5 mm, the prosthesis body is made of hydrogel material, and the inclination angle between the arc-shaped cylindrical hole and the bottom surface of the prosthesis body is 45°; The production method comprises the following steps: S1. Perform wrist CT scans on healthy volunteers and patients, and import the scanned imaging data into medical software to reconstruct a complete trapezium model; S2. Perform simulated cutting on the reconstructed trapezium model of a healthy volunteer to determine the best cutting path and remove the proximal 3 / 4 along the vertical direction of the central axis of the trapezium model; S3, simulate cutting on the reconstructed trapezium model of the patient, determine the best cutting path, and remove the distal 1 / 4 along the vertical direction of the central axis of the trapezium model; S4, replacing the 1 / 4 trapezium model of the patient with the 1 / 4 trapezium model remaining after resection of the healthy volunteer, and then scaling the 1 / 4 trapezium model of the healthy volunteer with medical software to match the size and surface of the articular surface of the base of the first metacarpal bone of the patient; S5. Design a connecting column at the proximal end of the central axis of the matched 1 / 4 trapezium model; S6. Design arc-shaped cylindrical holes on the palmar, dorsal and radial sides of the matched 1 / 4 trapezium model; S7. Use 3D printing to print out the designed model to obtain a partial replacement trapezium prosthesis.

2. The method for manufacturing a partially replaced trapezium prosthesis according to claim 1, characterized in that: In step S1, the medical software is Mimics16.0.

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