A three-action acetabular prosthesis implant

Abstract

The present invention relates to a three-motion acetabular prosthetic implant, comprising a main kinematic pair, a first kinematic pair, a second kinematic pair and a third kinematic pair that are meshed in sequence, wherein the main kinematic pair is fixed in the acetabulum, and the third kinematic pair is coupled with the femoral stem head to realize the freedom of the femur to move in the anterior-posterior, rotational and lateral directions relative to the acetabulum. Compared with the prior art, the three-motion acetabular prosthetic implant replicates the natural anatomical structure of the hip joint, and they form a ball-and-socket joint with the same three degrees of freedom as the natural hip joint, achieving anterior-posterior, rotational and lateral movements through the movement of each kinematic pair. The present invention realizes a large range of motion of the three-motion acetabular prosthetic implant by cooperating with four parts. The three-motion acetabular prosthetic implant provided by the present invention includes but is not limited to being used for replacing a patient's hip joint.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a three-motion acetabular prosthesis implant. Background Art

[0002] Joint replacement, also known as artificial hip replacement, is a procedure in which an artificial prosthesis, consisting of the femoral part and the acetabulum part, is fixed to normal bone using bone cement and screws to replace the diseased joint.

[0003] The natural anatomy of the hip is based on a ball-and-socket joint, with the "ball" being the head of the femur, or thighbone, and the "socket" being the acetabulum, in the pelvis. The ball can rotate within the socket with three degrees of freedom. The first degree of freedom represents forward and backward movement (flexion / extension) of the femur relative to the pelvis, which occurs primarily when the leg swings back and forth, such as when walking, running, or kicking a ball. The second degree of freedom represents rotation (medial / lateral rotation) of the femur relative to the pelvis, which occurs primarily when the leg twists relative to the torso, such as when rotating the body to plant the foot on the ground or into a cross-legged sitting position. The third degree of freedom represents lateral movement of the femur relative to the pelvis (abduction / adduction), which occurs primarily when the leg swings sideways, such as when extending the leg for balance or avoiding an obstacle.

[0004] The traditional acetabular cup connection method uses a ball-and-socket structure. After the ball head mates with the femoral stem, hip joint movement is achieved by rotating the ball head. However, this movement mechanism greatly limits the patient's mobility after implantation. Patients cannot perform large hip joint movements such as squats, which can lead to a series of problems such as implant dislodgement.

[0005] Hip prostheses known for total hip replacement may include two key components: an acetabular component and a femoral head component. Known acetabular prostheses can replicate the function and general shape of the acetabular socket and can be secured to the patient's acetabulum by any suitable method, including bone cement, screws and / or bone growth inducing materials. Known femoral head components are configured to resemble and replicate the function and general shape of a natural femoral head. Extending from the femoral head is a known component that engages the patient's femoral shaft. Some known femoral head and femoral stem components are integrally formed (as a whole) of a single material, such as stainless steel or cobalt-chromium alloy. Other known femoral head and stem components are formed separately, adapted to be joined to each other, and can be formed of the same or different materials. In the latter case, the femoral head can be formed of a ceramic material, such as alumina, or a metal, such as stainless steel or cobalt-chromium alloy. Known hip prostheses replicate the natural anatomical structure of the hip joint, forming a ball-and-socket joint.

[0006] Chinese patent CN104546227A discloses a modular dual-motion acetabular prosthesis designed to address the high risk of hip dislocation caused by developmental dysplasia of the hip, bone loss, joint or soft tissue relaxation, etc.; it includes a metal acetabular cup, a metal liner, a polyethylene liner and a metal ball head connected to the femoral stem; the metal acetabular cup is fixed by press-fit and supplemented by acetabular screws to enhance the initial mechanical stability of the acetabular prosthesis until the metal acetabular cup is biologically fixed; the metal liner and the metal acetabular cup are locked by tapered fit, and the end face ridge of the metal liner is placed in the groove of the metal acetabular cup to prevent the metal liner from rotating in the metal acetabular cup; the inner and outer surfaces of the polyethylene liner and the inner spherical surface of the metal liner are both smooth spherical surfaces, and the metal ball head is pressed into the polyethylene liner by a special tool; the movement of the joint prosthesis is achieved by the movement of two joint bearing surfaces between the outer spherical surface of the metal ball head and the inner spherical surface of the polyethylene liner, and between the outer spherical surface of the polyethylene liner and the inner spherical surface of the metal liner. However, this patent is for a dual-action acetabular cup, which uses two kinematic pairs to increase the angle of motion, allowing patients to have a larger angle of motion after implantation, but it cannot enable patients to squat and other movements. Summary of the Invention

[0007] The purpose of the present invention is to provide a three-motion acetabular prosthetic implant. The three-motion acetabular prosthetic implant replicates the natural anatomical structure of the hip joint, forming a ball-and-socket joint with the same three degrees of freedom as the natural hip joint, achieving forward, backward, rotational, and lateral movement through the movement of each kinematic pair. The present invention achieves a large range of motion of the three-motion acetabular prosthetic implant through the coordination of four parts. The three-motion acetabular prosthetic implant provided by the present invention includes but is not limited to being used to replace a patient's hip joint.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A three-motion acetabular prosthetic implant comprises a main kinematic pair, a first kinematic pair, a second kinematic pair and a third kinematic pair that are engaged in sequence. The main kinematic pair is fixed in the acetabulum, and the third kinematic pair is coupled to the femoral stem head to realize the freedom of the femur to move in the anterior-posterior, rotational and lateral directions relative to the acetabulum.

[0010] Furthermore, the third kinematic pair is composed of a third outer kinematic pair and a third inner kinematic pair, wherein the third outer kinematic pair refers to the outer surface of the third kinematic pair, and the third inner kinematic pair refers to the inner surface of the third kinematic pair.

[0011] The third inner motion pair is provided with a third inner motion pair groove matching the femoral stem head, and the femoral stem head is rigidly coupled to the third inner motion pair groove.

[0012] After coupling, the femoral stem head and the third kinematic pair can be regarded as a linked and inseparable integral component. Conversely, the lateral movement of the third kinematic pair is driven by the lateral movement of the femoral stem head.

[0013] Furthermore, the cross section of the groove of the third inner motion pair is elliptical, and the third outer motion pair is formed by symmetrically splicing circular wheels.

[0014] Furthermore, the second kinematic pair is composed of a second outer kinematic pair and a second inner kinematic pair, wherein the second outer kinematic pair refers to the outer surface of the second kinematic pair, and the second inner kinematic pair refers to the inner surface of the second kinematic pair.

[0015] The second inner kinematic pair is provided with a second inner kinematic pair groove matching the third outer kinematic pair, and the third outer kinematic pair is engaged with the second inner kinematic pair groove to realize the freedom of lateral movement of the femur relative to the acetabulum.

[0016] Thus, after the second kinematic pair and the third kinematic pair are assembled, the third kinematic pair can rotate within the second kinematic pair, achieving the purpose of lateral movement (abduction / adduction) of the prosthesis, which mainly occurs when swinging the leg sideways, such as when extending the leg to maintain balance or bypass an obstacle.

[0017] Furthermore, the second notch is provided vertically below the central axis of the second kinematic pair, the third notch is provided at the front end of the second outer kinematic pair, and the first notch is provided at the rear end of the second outer kinematic pair.

[0018] The vertical projection of the second notch is identical in shape to the vertical projection of the third kinematic pair and has a matching size. The second notch enables the third kinematic pair to enter the second kinematic pair vertically from the lower end of the central axis of the second kinematic pair.

[0019] The third notch is provided in the horizontal direction of the second kinematic pair, and the third notch is used to enable the third kinematic pair to achieve a rotation range of 180° during the rotation process when the femoral stem is attached to the third kinematic pair;

[0020] The depths of the first notch and the third notch are arranged on the same horizontal plane, so that the rotation of the femoral stem reaches 180°.

[0021] The first notch, the second notch and the third notch are designed according to the projection surface shapes in the horizontal and vertical directions of the motion trajectory generated when the femoral stem rotates in the third kinematic pair. The first notch, the second notch and the third notch of the second kinematic pair can allow the third kinematic pair to enter from the vertical direction and be assembled with the second kinematic pair, allowing the femoral stem to complete nearly 180° of lateral movement after assembly.

[0022] Furthermore, in the above, the cross section of the second inner motion pair groove and the second outer motion pair are both formed by splicing two ellipses of the same size.

[0023] Furthermore, the first kinematic pair is composed of a first outer kinematic pair and a first inner kinematic pair, wherein the first outer kinematic pair refers to the outer surface of the first kinematic pair, and the first inner kinematic pair refers to the inner surface of the first kinematic pair.

[0024] The first inner kinematic pair is provided with a first inner kinematic pair groove matching the second outer kinematic pair, and the second outer kinematic pair is engaged with the first inner kinematic pair groove to realize the freedom of rotation of the femur relative to the acetabulum.

[0025] Thus, after the first kinematic pair and the second kinematic pair are assembled, the second kinematic pair can rotate within the first kinematic pair, thereby achieving the purpose of the three-motion acetabular prosthetic implant being able to perform rotational movement (medial / lateral rotation), which mainly occurs when the leg is twisted relative to the direction of the torso, such as when the foot is placed on the ground to rotate the body or enter a cross-legged sitting position.

[0026] Furthermore, in the above, the cross section of the first inner motion secondary groove is formed by splicing two ellipses of the same size.

[0027] Furthermore, the first external motion pair is composed of a first rotating pair, a first fixed groove and a first enveloping pair. The first rotating pair is arranged at one end connected to the main motion pair. The first rotating pair, the first fixed groove and the first enveloping pair constitute a train wheel structure. Through the circular disc structure on the side of the first rotating pair, the first motion pair can rotate stably and directionally in the main motion pair.

[0028] As a preferred technical solution, the maximum outer diameter of the first rotating pair is 28 mm, the thickness is 5 mm, and the roundness of the first fixing groove is 1.8 mm.

[0029] As a preferred technical solution, the first rotational pair is a circular pancake structure on the first outer motion pair.

[0030] Furthermore, the main body motion pair is composed of a main body outer motion pair and a main body inner motion pair, the main body outer motion pair refers to the outer surface of the main body motion pair, and the main body inner motion pair refers to the inner surface of the main body motion pair.

[0031] The main body inner motion pair is provided with a main body inner motion pair groove that matches the first external motion pair. The first external motion pair is engaged with the main body inner motion pair groove to achieve the freedom of the femur to move forward and backward relative to the acetabulum.

[0032] This allows the first kinematic pair to remain within the main body kinematic pair, allowing the first kinematic pair to rotate within the main body kinematic pair, thereby achieving the purpose of the three-motion acetabular prosthetic implant being able to move forward and backward (flexion / extension), which mainly occurs when the legs swing back and forth, such as walking, running or kicking a ball.

[0033] Furthermore, the outer motion pair of the main body is provided with an assembly positioning groove, and the assembly positioning groove is provided on the central axis of the outer motion pair of the main body and is located at the top end of the outer motion pair of the main body.

[0034] As a preferred technical solution, the depth of the assembly positioning groove is 5.5 mm;

[0035] The assembly positioning groove is approximately in the shape of an isosceles triangle on the vertical projection plane. This design prevents the main motion pair from loosening, rotating or other displacement risks after implantation and assembly. The unique geometric design of the assembly positioning groove, which changes from large to small, makes the geometric shape of the assembly positioning groove simple and clear, ensuring that the physician can easily and correctly determine the positioning direction of the implant during the operation, ensuring a safe and reliable implantation process during the operation, and the implantation process is carried out accurately. If the positioning is wrong, the assembly positioning groove will give obvious feedback, that is, the main motion pair is not snapped into the assembly positioning groove, and the physician can immediately correct the positioning direction, ensuring the correctness and efficiency of the operation.

[0036] The assembly positioning groove enables the main kinematic pair to be accurately fixed in the patient's body. During the movement of each kinematic pair, the main kinematic pair is always fixed in the patient's body at the positioning angle. The main kinematic pair serves as the most important basic firmware in the acetabular prosthesis described in the present invention.

[0037] Furthermore, the outer moving pair of the main body is provided with a plurality of assembly ring grooves, which are arranged around the outer moving pair of the main body. The assembly ring grooves are composed of three groups of ring grooves with an equal distance of 5 mm. Starting from the assembly positioning groove from top to bottom, the cross-section of each assembly ring groove is a circle with a radius of 0.6 mm, 0.8 mm, and 1 mm respectively.

[0038] As a preferred technical solution, after the main kinematic pair is implanted and assembled, the assembly ring groove generates compressive stress on the implant surface through its circular grooves equidistant by 5 mm, so that the main kinematic pair can be firmly implanted into the patient's body without the risk of shaking, loosening or even dislocation; the assembly ring groove cooperates with the above-mentioned assembly positioning groove. During the implantation process by the physician, when the main kinematic pair is correctly positioned in the direction of the assembly positioning groove, the assembly ring groove and the assembly surface are clamped in sequence in the vertical direction. During the correct implantation process, positive feedback from the assembly ring groove is received, which reduces surgical risks such as implant failure and positioning errors, and provides protection for the patient's safety.

[0039] As a preferred technical solution, the shape and size of the main motion pair match the patient's acetabulum, and the main motion pair can use screws, bone cement, bone growth inducing material or any other combination to fix the three-motion acetabular prosthesis implant into the acetabulum;

[0040] The external kinematic pair of the main body can be adjusted in any way according to the actual usage. To a certain extent, it can be easily combined with the patient's acetabulum, which will reduce the possibility of prosthesis loosening or surgical failure.

[0041] Furthermore, the opening directions of the third inner kinematic pair groove, the second inner kinematic pair groove, the first inner kinematic pair groove, and the inner kinematic pair groove of the main body are all the same. This opening design allows the third kinematic pair to be assembled in a vertical direction, the second kinematic pair to be assembled in a horizontal direction, and the first kinematic pair to be assembled in a vertical direction. Each adjacent kinematic pair is assembled in a different direction, thereby reducing the risk of dislocation of each kinematic pair when the patient exercises in daily life. The opening design also takes into account the situation that the patient may make large movements in daily life. The femoral stem head will not collide with the acetabular prosthesis due to a large rotation angle. The maximum opening angle of each kinematic pair is the same, ensuring that each kinematic pair will not collide with the femoral stem when the femoral stem rotates, thereby reducing the risk of dislocation or collision of the acetabular prosthesis implant due to patient movement in daily life. When the patient squats in daily life, the opening allows the three-motion acetabular prosthesis implant to move without the risk of dislocation or collision of the femoral stem head connected to the third kinematic pair.

[0042] As a preferred technical solution, the structures of the main body external kinematic pair, the main body internal kinematic pair, the first external kinematic pair, the first internal kinematic pair, the second external kinematic pair, the second internal kinematic pair, the third external kinematic pair and the third internal kinematic pair are all smooth and continuous transitions. When they contact and rub against each other, there are no protrusions, grooves, edges or any other sudden geometric changes, thereby further improving the wear resistance of the prosthetic implant.

[0043] As a preferred technical solution, the main kinematic pair, the first kinematic pair, the second kinematic pair and the third kinematic pair are made of "alternating polymer and metal materials" or "alternating polymer and ceramic materials" or any combination of "polymer, metal and ceramic materials".

[0044] As a preferred technical solution, the polymer material can be polyethylene, such as ultra-high molecular weight polyethylene (UHMWPE) or cross-linked polyethylene (XPE), or other suitable polymers; the metal material can be stainless steel, cobalt-chromium alloy, or any other suitable metal alloy; and the ceramic material can be aluminum oxide (Al2O3), zirconium oxide (ZrC>2), or any suitable technical ceramic material. The polymer material is used alternately with the metal or ceramic material, and they can exhibit excellent wear resistance when friction occurs.

[0045] The working principle of the present invention is as follows:

[0046] In the present invention, Figure 25 The train wheel structure design shown is applied to the first kinematic pair, the second kinematic pair, and the third kinematic pair, which guides the direction of wheel rotation by enveloping the rails through the large discs protruding on both sides of the train wheel. This structural feature is used in the design of the kinematic pair in the present invention, so that the kinematic pair can achieve the purpose of enveloping through the train wheel structure and the corresponding grooves, so that the kinematic pair can rotate stably in a directional manner.

[0047] like Figure 10 As shown, the first outer kinematic pair consists of a first rotating pair, a first fixed groove, and a first enveloping pair. The first rotating pair guides the directional rotation of the first kinematic pair in the main kinematic pair through a circular disk on the side. Its flat design takes into account the overall size of the first kinematic pair. This asymmetric train wheel structure reduces the overall volume of the first kinematic pair, allowing the first kinematic pair to be enveloped in it by the main kinematic pair. Figure 26 It is a symmetrical train wheel structure. The overall volume of the first moving pair is huge, which affects the volume of the main moving pair, making the main moving pair too large and not meeting the size of the prosthetic implant; the first fixing groove stabilizes the first moving pair in the main moving pair through a unique groove structure. This design avoids the risk of structural defects of the prosthetic implant due to wear after a long period of friction, which causes the moving pair to shake or displace in the main pair; the first enveloping pair guides the first moving pair to rotate in the main moving pair through a circular surface, but unlike the first rotating pair, the first enveloping pair has a larger roundness radius, which allows the first inner moving pair to have enough space to accommodate the second and third moving pairs. The enveloping pair allows the second moving pair to enter horizontally and cooperate with the first inner moving pair through a horizontal opening.

[0048] like Figure 14As shown, the second outer kinematic pair is composed of a second rotating pair, a second fixed groove and a second enveloping pair to form a symmetrical train wheel structure. The second rotating pair guides the second kinematic pair to rotate in a directional manner in the first kinematic pair through the circular disk on the top; the second fixed groove stabilizes the second kinematic pair in the first kinematic pair through a unique groove structure. This design also avoids the risk of shaking or displacement of the second kinematic pair during movement due to wear; the second enveloping pair guides the second kinematic pair to rotate in the first kinematic pair through the circular surface, and the second enveloping pair allows the third kinematic pair to enter in a vertical direction and cooperate with the second inner kinematic pair through the lower end opening.

[0049] like Figure 22 As shown, the third external kinematic pair consists of an enveloping revolute pair and a positioning groove, forming a symmetrical train wheel structure. The enveloping revolute pair guides the third kinematic pair's directional rotation within the second internal kinematic pair via circular discs on its left and right sides. The positioning groove stabilizes the third kinematic pair within the second kinematic pair through a unique groove structure. Similarly, this design avoids the risk of shaking or even displacement caused by wear. The enveloping revolute pair, through a horizontal opening, allows the femoral stem to enter and mate with the third internal kinematic pair.

[0050] The femoral stem head is rigidly coupled through the third internal kinematic pair groove of the third internal kinematic pair; the third kinematic pair is engaged through the second internal kinematic pair groove of the second internal kinematic pair; the second kinematic pair is engaged through the first internal kinematic pair groove included in the first internal kinematic pair; the first kinematic pair is engaged through the main body internal kinematic pair groove included in the main body internal kinematic pair; the main body kinematic pair fixes the three-motion acetabular prosthetic implant to the acetabulum through screws, bone cement, bone growth inducing material or any other combination.

[0051] When the femoral stem head moves, due to its rigid coupling with the third kinematic pair, the two components can be considered as a single kinematic pair. Therefore, the following principle explanation will skip the motion transmission of the femoral stem, as it is not part of the prosthesis in this invention.

[0052] The working principle will be described in reverse order to explain the status of each component when movement occurs. When movement occurs, the movement trend is transmitted in the order of femoral stem, third kinematic pair, second kinematic pair, first kinematic pair, and main kinematic pair.

[0053] During lateral motion (abduction / adduction), the femoral stem transmits lateral motion to the third kinematic pair. The third kinematic pair is constrained by the groove in the second internal kinematic pair, allowing only lateral motion. The third kinematic pair allows approximately 180° of rotation within the groove, i.e., lateral motion. The remaining kinematic pair components, however, are constrained by their respective motion limitations and do not move.

[0054] When rotation (inside / outside rotation) occurs, the third kinematic pair transmits the rotational trend to the second kinematic pair. The third kinematic pair cannot perform rotational motion alone due to the limitation of its engagement with the groove of the second inner kinematic pair. And because the groove of the second inner kinematic pair only allows the third kinematic pair to perform lateral motion, when rotational motion occurs, the third kinematic pair is restricted in the groove of the second inner kinematic pair in an interlocking relationship, and no lateral motion occurs. At this time, the third kinematic pair and the second kinematic pair can be regarded as an integral component. The second kinematic pair is restricted by the groove of the first inner kinematic pair and rotational motion occurs. The groove of the first inner kinematic pair allows the second kinematic pair to rotate about 180°, that is, the previously assumed rotational motion occurs. In this process, the third kinematic pair is included in the second kinematic pair in an interlocking manner, and a rotational motion dominated by the second kinematic pair occurs together.

[0055] When forward and backward movement (flexion / extension) occurs, the third kinematic pair and the second kinematic pair transmit the forward and backward movement trend to the first kinematic pair in an interlocked state. Due to the limitation of the second kinematic pair's engagement with the groove of the first inner kinematic pair, it is impossible for the third kinematic pair to move forward and backward alone. In addition, due to the limitations of the grooves that mesh with each other between the third kinematic pair and the second kinematic pair, forward and backward movement cannot be achieved. Therefore, when forward and backward movement occurs, the third kinematic pair, the second kinematic pair and the first kinematic pair will be regarded as an integral component. Because the first kinematic pair is engaged with the groove of the kinematic pair in the main body, it is allowed to move forward and backward. Therefore, when movement occurs, the first kinematic pair will be able to rotate about 180° to move forward and backward due to the transmission of the forward and backward movement trend. At this time, the third kinematic pair and the second kinematic pair are contained in the first kinematic pair and move forward and backward together with the first kinematic pair in an interlocking manner.

[0056] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0057] 1. The present invention uses a three-motion acetabular prosthetic implant to allow the femur to rotate within the acetabulum with three degrees of freedom. The first degree of freedom represents the forward and backward movement of the femur relative to the acetabulum (flexion / extension), which mainly occurs when the leg is swung back and forth, such as walking, running, or kicking a ball. The second degree of freedom represents the rotation of the femur relative to the acetabulum (medial / lateral rotation), which mainly occurs when the leg is twisted relative to the trunk, such as when the foot is placed on the ground to rotate the body or enter a cross-legged sitting position. The third degree of freedom represents the lateral movement of the femur relative to the acetabulum (abduction / adduction), which mainly occurs when the leg is swung sideways, such as when extending the leg to maintain balance or to bypass an obstacle.

[0058] 2. The three-action acetabular prosthetic implant provided by the present invention consists of a main kinematic pair, a first kinematic pair, a second kinematic pair, and a third kinematic pair. This design effectively creates a larger contact area. While existing conventional acetabular prostheses have a single contact surface, the three-action acetabular prosthetic implant provided by the present invention has three contact surfaces, significantly increasing the contact area. Therefore, applying the same load to the joint with the larger contact surface creates three pairs of surfaces, each with a contact pressure lower than that experienced by a conventional ball-and-socket joint, effectively reducing wear.

[0059] 3. In the technical solution of the three-motion acetabular prosthetic implant described in the present invention, by coordinating each kinematic pair, the third kinematic pair is unable to rotate with the first kinematic pair during movement, thereby preventing it from dislocating through the groove of the first internal kinematic pair. Each kinematic pair can follow this design, so when the prosthesis moves as a whole, each kinematic pair forms an interlocking state without causing other components to dislocate due to excessive movement. Each kinematic pair relies on the designed groove for movement and has a wide range of motion angles. This interlocking, non-interfering motion relationship greatly reduces the risk of dislocation of the prosthesis when used by the patient.

[0060] 4. In the technical solution of the three-motion acetabular prosthetic implant described in the present invention, when lateral, rotational, and forward and backward movement occurs, each component will interlock with other components due to the limitations of its own groove. This interlocking relationship eliminates the need for any form of attachments or connections in the first, second, and third kinematic pairs of the three-motion acetabular prosthetic implant described in the present invention. This interlocking relationship reduces the risk of inadvertent dislocation of the components during movement, as each is restricted to movement within its corresponding groove. This greatly reduces the possibility of the implant falling out during exercise.

[0061] 5. In the technical solution of the three-motion acetabular prosthetic implant described in the present invention, each kinematic pair has a unique groove design on its inner side. Each groove only allows the kinematic pair it engages to move in one direction. For example, the third kinematic pair only allows lateral movement and cannot independently move forward and backward. Furthermore, due to the interlocking design of the kinematic pairs, the dimensions of each component vary. For example, the main kinematic pair and the first kinematic pair are significantly different in size. The unique groove of the main kinematic pair intuitively reflects the meshing relationship with the first kinematic pair. This simple and intuitive structural design makes the installation of the acetabular prosthesis of this embodiment simple and intuitive, making it error-free during surgery.

[0062] 6. In the technical solution of the three-motion acetabular prosthesis implant described in the present invention, the main kinematic joint, the first kinematic joint, and the second kinematic joint all have openings in the same direction and position. This allows the acetabular prosthesis to move in daily life, such as when squatting, without the risk of dislocation or impact of the femoral stem head connected to the third kinematic joint. This unique opening provides intuitive structural correspondence during installation, with the openings of each component maintaining the same direction and position. This reduces the possibility of installation errors.

[0063] 7. In the technical solution of the three-motion acetabular prosthetic implant described in the present invention, the unique groove contained in each component is also a feature that greatly distinguishes it from the known ball-and-socket prosthesis. The known ball-and-socket prosthesis will be axially symmetrical during installation, and precise alignment, marking, etc. are required to correctly guide the physician to choose the correct implantation method during installation. The unique groove of this embodiment is like a "one-to-one precise snap", and each kinematic pair can be implanted in the correct order. During installation in this embodiment, the installation steps may be: first engage the first kinematic pair and the second kinematic pair, and rotate 180° to ensure their engagement. Fix the main kinematic pair to the patient's acetabulum. Engage the engaged first and second kinematic pairs with them. Fix the third kinematic pair to the patient's femur. Engage the third kinematic pair with other engaged components. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of the structure of the three-motion acetabular prosthesis implant of the present invention;

[0065] Figure 2 is a cross-sectional view of the three-motion acetabular prosthesis implant of the present invention;

[0066] Figure 3 A physical diagram of the three-motion acetabular prosthesis implant of the present invention;

[0067] Figure 4 Schematic diagram of the disassembled structure of the three-motion acetabular prosthesis implant of the present invention;

[0068] Figure 5 This is a disassembled physical diagram of the three-motion acetabular prosthesis implant of the present invention;

[0069] Figure 6 Schematic diagram of the top view of the main body kinematic pair in the present invention;

[0070] Figure 7 Schematic diagram of the side view of the main body kinematic pair in the present invention;

[0071] Figure 8 Schematic diagram of the front view structure of the main body kinematic pair in the present invention;

[0072] Figure 9 Schematic diagram of the bottom view of the first kinematic pair in the present invention;

[0073] Figure 10 Schematic diagram of the top view of the first kinematic pair in the present invention;

[0074] Figure 11 Schematic diagram of the side structure of the first kinematic pair in the present invention;

[0075] Figure 12 Schematic diagram of the front view of the first kinematic pair in the present invention;

[0076] Figure 13 Schematic diagram of the overall structure of the second kinematic pair in the present invention;

[0077] Figure 14 Schematic diagram of the side structure of the second kinematic pair in the present invention;

[0078] Figure 15 Schematic diagram of the top view of the second kinematic pair in the present invention;

[0079] Figure 16 Schematic diagram of the front view of the second kinematic pair in the present invention;

[0080] Figure 17 A bottom view of the second kinematic pair in the present invention;

[0081] Figure 18 for Figure 17 A partial enlarged view of the middle shaded area;

[0082] Figure 19 Schematic diagram of the coordinated use of the second kinematic pair, the third kinematic pair, and the femoral stem in the present invention;

[0083] Figure 20 Schematic diagram of the front view of the third kinematic pair in the present invention;

[0084] Figure 21 Schematic diagram of the side structure of the third kinematic pair in the present invention;

[0085] Figure 22 Schematic diagram of the overall structure of the third kinematic pair in the present invention;

[0086] Figure 23 Schematic diagram of the overall structure of the femoral stem in the present invention;

[0087] Figure 24 Schematic diagram of the use of the femoral stem and the three-motion acetabular prosthesis implant in the present invention;

[0088] Figure 25 This is a schematic diagram of the structure of the train wheel in the working principle of the present invention;

[0089] Figure 26 It is a structural schematic diagram of the symmetrical first kinematic pair in the working principle of the present invention.

[0090] Explanation of the accompanying figures: 1. Main body kinematic pair, 11. Main body external kinematic pair, 111. Assembly positioning groove, 112. Assembly ring groove, 12. Main body internal kinematic pair, 121. Main body internal kinematic pair groove, 2. First kinematic pair, 21. First external kinematic pair, 211. First rotational pair, 212. First fixed groove, 213. First envelope pair, 22. First internal kinematic pair, 221. First internal kinematic pair groove, 3. Second kinematic pair, 31. Second external kinematic pair, 311. First notch, 312. Second notch, 313. Third notch, 314. Second rotational pair, 315. Second fixed groove, 316. Second envelope pair, 32. Second internal kinematic pair, 321. Second internal kinematic pair groove, 4. Third kinematic pair, 41. Third external kinematic pair, 411. Enveloping rotational pair, 412. Positioning groove, 42. Third internal kinematic pair, 421. Third internal kinematic pair groove, 5. Femoral stem head. DETAILED DESCRIPTION

[0091] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0092] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0093] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0094] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0095] The following describes some embodiments of the present invention in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0096] Example 1

[0097] See also Figures 1 to 22 This embodiment provides a three-motion acetabular prosthetic implant, including a main motion pair 1, a first motion pair 2, a second motion pair 3 and a third motion pair 4 that are engaged in sequence. The main motion pair 1 is fixed in the acetabulum, and the third motion pair 4 is coupled with the femoral stem head 5 to realize the freedom of the femur to move forward and backward, rotationally and laterally relative to the acetabulum.

[0098] In this embodiment, the third kinematic pair 4 is composed of a third outer kinematic pair 41 and a third inner kinematic pair 42. The third outer kinematic pair 41 refers to the outer surface of the third kinematic pair 4, and the third inner kinematic pair 42 refers to the inner surface of the third kinematic pair 4.

[0099] The third inner motion pair 42 is provided with a third inner motion pair groove 421 that matches the femoral stem head 5. The femoral stem head 5 is rigidly coupled to the third inner motion pair groove 421.

[0100] After coupling, the femoral stem head 5 and the third kinematic pair 4 can be regarded as an interlocking and inseparable integral component. Conversely, the lateral movement of the third kinematic pair 4 is driven by the lateral movement of the femoral stem head 5 to drive the third kinematic pair 4 to move laterally.

[0101] In this embodiment, the cross section of the third inner motion pair groove 421 is elliptical, and the third outer motion pair 41 is formed by symmetrically splicing circular wheels.

[0102] In this embodiment, the second kinematic pair 3 is composed of a second outer kinematic pair 31 and a second inner kinematic pair 32 , wherein the second outer kinematic pair 31 refers to the outer surface of the second kinematic pair 3 , and the second inner kinematic pair 32 refers to the inner surface of the second kinematic pair 3 .

[0103] The second inner kinematic pair 32 is provided with a second inner kinematic pair groove 321 matching the third outer kinematic pair 41. The third outer kinematic pair 41 engages with the second inner kinematic pair groove 321 to achieve the degree of freedom of lateral movement of the femur relative to the acetabulum.

[0104] Thus, after the second kinematic pair 3 and the third kinematic pair 4 are assembled, the third kinematic pair 4 can rotate within the second kinematic pair 3, so that the prosthesis can move laterally in abduction / adduction, which mainly occurs when the leg is swung sideways, such as when extending the leg to maintain balance or bypass an obstacle.

[0105] In this embodiment, a second notch 312 is provided vertically below the central axis of the second kinematic pair 3, a third notch 313 is provided at the front end of the second outer kinematic pair 31, and a first notch 311 is provided at the rear end of the second outer kinematic pair 31.

[0106] The vertical projection shape of the second notch 312 is the same as the vertical projection shape of the third kinematic pair 4 and the size matches. The second notch 312 enables the third kinematic pair 4 to enter the second kinematic pair 3 from the lower end of the central axis of the second kinematic pair 3 in a vertical direction.

[0107] The third notch 313 is provided in the horizontal direction of the second kinematic pair 3, and the third notch 313 is used to enable the third kinematic pair 4 to achieve a rotation range of 180° during the rotation process when the femoral stem is attached;

[0108] The depths of the first notch 311 and the third notch 313 are set on the same horizontal plane, so that the rotation of the femoral stem reaches 180°.

[0109] The first notch 311, the second notch 312 and the third notch 313 are designed according to the projection surface shapes in the horizontal and vertical directions of the motion trajectory generated when the femoral stem rotates in the third kinematic pair 4. The first notch 311, the second notch 312 and the third notch 313 of the second kinematic pair 3 can allow the third kinematic pair 4 to enter from the vertical direction and be assembled with the second kinematic pair 3, allowing the femoral stem to complete nearly 180° of lateral movement after assembly.

[0110] In this embodiment, the cross sections of the second inner motion pair groove 321 and the second outer motion pair 31 are formed by splicing two ellipses of the same size.

[0111] In this embodiment, the first kinematic pair 2 is composed of a first outer kinematic pair 21 and a first inner kinematic pair 22. The first outer kinematic pair 21 refers to the outer surface of the first kinematic pair 2, and the first inner kinematic pair 22 refers to the inner surface of the first kinematic pair 2.

[0112] The first inner kinematic pair 22 is provided with a first inner kinematic pair groove 221 matching the second outer kinematic pair 31. The second outer kinematic pair 31 engages with the first inner kinematic pair groove 221 to achieve the degree of freedom of rotation of the femur relative to the acetabulum.

[0113] Thus, after the first kinematic pair 2 and the second kinematic pair 3 are assembled, the second kinematic pair 3 can rotate within the first kinematic pair 2, thereby achieving the purpose of the three-motion acetabular prosthetic implant being able to rotate medially / laterally, which mainly occurs when the leg is twisted relative to the direction of the torso, such as when the foot is placed on the ground to rotate the body or enter a cross-legged sitting position.

[0114] In this embodiment, the cross section of the first inner motion auxiliary groove 221 is formed by splicing two ellipses of the same size.

[0115] In this embodiment, the first external kinematic pair 21 is composed of a first rotating pair 211, a first fixed groove 212 and a first enveloping pair 213. The first rotating pair 211 is arranged at one end connected to the main kinematic pair 1. The first rotating pair 211, the first fixed groove 212 and the first enveloping pair 213 constitute a train wheel structure. Through the circular disc structure on the side of the first rotating pair 211, the first kinematic pair 2 can rotate stably and directionally in the main kinematic pair 1.

[0116] In this embodiment, the maximum outer diameter of the first rotation pair 211 is 28 mm, the thickness is 5 mm, and the roundness of the first fixing groove 212 is 1.8 mm.

[0117] In this embodiment, the first rotational pair 211 is a circular structure on the first outer kinematic pair 21 .

[0118] In this embodiment, the main body motion pair 1 is composed of a main body outer motion pair 11 and a main body inner motion pair 12. The main body outer motion pair 11 refers to the outer surface of the main body motion pair 1, and the main body inner motion pair 12 refers to the inner surface of the main body motion pair 1.

[0119] The main body inner motion pair 12 is provided with a main body inner motion pair groove 121 that matches the first external motion pair 21. The first external motion pair 21 engages with the main body inner motion pair groove 121 to achieve the freedom of the femur to move forward and backward relative to the acetabulum.

[0120] Thereby, the first kinematic pair 2 is maintained in the kinematic pair 12 in the main body, and the first kinematic pair 2 can rotate in the kinematic pair 12 in the main body, so as to achieve the purpose of the three-motion acetabular prosthetic implant being able to move forward and backward in flexion / extension, which mainly occurs when the legs swing forward and backward, such as walking, running or kicking a ball.

[0121] In this embodiment, an assembly positioning groove 111 is provided on the main body outer motion pair 11 . The assembly positioning groove 111 is provided on the central axis of the main body outer motion pair 1 and is located at the top end of the main body outer motion pair 11 .

[0122] In this embodiment, the depth of the assembly positioning groove 111 is 5.5 mm;

[0123] In this embodiment, a plurality of assembly ring grooves 112 are further provided on the outer moving pair 11 of the main body. The assembly ring grooves 112 are arranged around the outer moving pair 11 of the main body. The assembly ring grooves 112 are composed of three groups of ring grooves with an equal distance of 5 mm. Starting from the assembly positioning groove 111 from top to bottom, the cross-section of each assembly ring groove 112 is a circle with a radius of 0.6 mm, 0.8 mm, and 1 mm respectively.

[0124] In this embodiment, the shape and size of the main kinematic pair 1 match the patient's acetabulum, and the main kinematic pair 1 can use screws, bone cement, bone growth inducing material or any other combination to fix the three-motion acetabular prosthesis implant into the acetabulum.

[0125] In this embodiment, the opening directions of the third inner motion pair groove 421, the second inner motion pair groove 321, the first inner motion pair groove 221 and the main body inner motion pair groove 121 are all the same. This opening design allows the third motion pair 4 to be assembled in a vertical direction, the second motion pair 3 to be assembled in a horizontal direction, and the first motion pair 2 to be assembled in a vertical direction. Each adjacent motion pair is assembled in a different direction, reducing the risk of each motion pair being dislocated when the patient exercises in daily life. The opening design also takes into account the situation that the patient exercises a large range of motion in daily life. The femoral stem head 5 will not collide with the acetabular prosthesis due to a large rotation angle. The maximum opening angle of each motion pair is the same, ensuring that each motion pair will not collide with the femoral stem when the femoral stem rotates, which reduces the risk of the acetabular prosthesis implant being dislocated or impacted due to the patient's movement in daily life. When the patient squats in daily life, the opening allows the femoral stem head 5 connected to the third motion pair 4 to be connected to the three-motion acetabular prosthesis implant during exercise without the risk of dislocation or impact.

[0126] In this embodiment, the structures of the main body external kinematic pair 11, the main body internal kinematic pair 12, the first external kinematic pair 21, the first internal kinematic pair 22, the second external kinematic pair 31, the second internal kinematic pair 32, the third external kinematic pair 41 and the third internal kinematic pair 42 are all smooth and continuous transitions. When they contact and rub against each other, there are no protrusions, grooves, edges or any other sudden geometric changes, thereby further improving the wear resistance of the prosthetic implant.

[0127] In this embodiment, the main kinematic pair 1, the first kinematic pair 2, the second kinematic pair 3 and the third kinematic pair 4 are made of "alternating polymer and metal materials" or "alternating polymer and ceramic materials" or any combination of "polymer, metal and ceramic materials".

[0128] In this embodiment, the polymer material can be polyethylene, such as ultra-high molecular weight polyethylene (UHMWPE) or cross-linked polyethylene (XPE), or other suitable polymers; the metal material can be stainless steel, cobalt-chromium alloy, or any other suitable metal alloy; and the ceramic material can be aluminum oxide (Al2O3), zirconium oxide (ZrC>2), or any other suitable technical ceramic material. The polymer material is used alternately with the metal or ceramic material, and when friction occurs, they exhibit excellent wear resistance.

[0129] In this embodiment, the size of the main kinematic pair 1 can be selected from #40mm to #72mm, and its size varies according to the size of the acetabulum and femur of each patient. When the main kinematic pair 1 is #52mm, the maximum size of the first kinematic pair 2 that matches #52 is approximately 40mm.

[0130] Example 2

[0131] See also Figures 23 to 24 The present embodiment provides a femoral stem, which is another artificial prosthesis combined with a three-motion acetabular prosthesis implant. The design of the stem head is similar to a cone, so that it can be rigidly coupled with the acetabular prosthesis. Both the femoral stem and the three-motion acetabular prosthesis implant are designed based on human bionics. In this way, the movement of the femoral stem is driven by the movement of the human thigh, and the movement is transmitted to the three-motion acetabular prosthesis implant, thereby realizing the movement of the human body in a bionic way.

[0132] This embodiment involves the assembly of the femoral stem, which is not part of the acetabulum implant of the present invention. Only the femoral stem head 5 is assembled with the third internal kinematic pair 42 during the implantation process. Therefore, this embodiment does not elaborate on the femoral stem. Figures 23 to 24 For conventional femoral stem structure design, such as Figure 23 It is a conventional femoral stem design, with the tip end implanted in the human femur, and the other end of the femoral stem head 5 structure is combined with the third inner motion pair groove 421. The femoral stem head 5 and the third inner motion pair groove 421 are press-fitted to achieve rigid coupling, so in the process of motion trend transmission, in this embodiment, the femoral stem head 5 and the third motion pair 4 can be temporarily regarded as a linked integral part, so as to simplify but not ambiguously explain the working principle. Figure 24 This is the positional relationship between the femoral stem and the third kinematic pair 4 when press-fitted, and the third inner kinematic pair 42 is "embedded" in the third inner kinematic pair groove 421.

[0133] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A three-action acetabular prosthesis implant, characterized in that: The invention comprises a main kinematic pair (1), a first kinematic pair (2), a second kinematic pair (3) and a third kinematic pair (4) which are engaged in sequence, wherein the main kinematic pair (1) is fixed in the acetabulum, and the third kinematic pair (4) is coupled with the femoral stem head (5) to realize the freedom of the femur to move in the anterior-posterior, rotational and lateral directions relative to the acetabulum; The first kinematic pair (2) is engaged with the main kinematic pair (1) to realize the freedom of the femur to move forward and backward relative to the acetabulum; the second kinematic pair (3) is engaged with the first kinematic pair (2) to realize the freedom of the femur to move in rotation relative to the acetabulum; the third kinematic pair (4) is engaged with the second kinematic pair (3) to realize the freedom of the femur to move in lateral direction relative to the acetabulum; The first kinematic pair (2) is composed of a first outer kinematic pair (21) and a first inner kinematic pair (22), wherein the first outer kinematic pair (21) refers to the outer surface of the first kinematic pair (2), and the first inner kinematic pair (22) refers to the inner surface of the first kinematic pair (2). The first outer kinematic pair (21) is composed of a first rotating pair (211), a first fixed groove (212) and a first enveloping pair (213). The first rotating pair (211) is provided at one end connected to the main kinematic pair (1). The first rotating pair (211), the first fixed groove (212) and the first enveloping pair (213) form an asymmetric train wheel structure. The first kinematic pair (2) is stably and directionally rotated in the main kinematic pair (1) through the circular disc structure on the side of the first rotating pair (211).

2. The three-motion acetabular prosthesis implant according to claim 1, characterized in that: The third kinematic pair (4) is composed of a third outer kinematic pair (41) and a third inner kinematic pair (42), wherein the third outer kinematic pair (41) refers to the outer surface of the third kinematic pair (4), and the third inner kinematic pair (42) refers to the inner surface of the third kinematic pair (4). A third inner motion pair groove (421) matching the femoral stem head (5) is provided in the third inner motion pair (42), and the femoral stem head (5) is rigidly coupled to the third inner motion pair groove (421).

3. The three-motion acetabular prosthesis implant according to claim 2, characterized in that: The cross section of the third inner motion pair groove (421) is elliptical, and the third outer motion pair (41) is formed by symmetrically splicing circular wheels.

4. The three-motion acetabular prosthesis implant according to claim 2, characterized in that: The second kinematic pair (3) is composed of a second outer kinematic pair (31) and a second inner kinematic pair (32), wherein the second outer kinematic pair (31) refers to the outer surface of the second kinematic pair (3), and the second inner kinematic pair (32) refers to the inner surface of the second kinematic pair (3). The second inner kinematic pair (32) is provided with a second inner kinematic pair groove (321) matching the third outer kinematic pair (41), and the third outer kinematic pair (41) engages with the second inner kinematic pair groove (321) to achieve the degree of freedom of lateral movement of the femur relative to the acetabulum.

5. The three-motion acetabular prosthesis implant according to claim 4, characterized in that: A second notch (312) is provided vertically below the central axis of the second kinematic pair (3), a third notch (313) is provided at the front end of the second outer kinematic pair (31), and a first notch (311) is provided at the rear end of the second outer kinematic pair (31). The vertical projection surface shape of the second notch (312) is identical to the vertical projection surface shape of the third kinematic pair (4) and matches the size thereof, and the second notch (312) enables the third kinematic pair (4) to enter the second kinematic pair (3) from the lower end of the central axis of the second kinematic pair (3) in a vertical direction; The third notch (313) is provided in the horizontal direction of the second kinematic pair (3), and the third notch (313) is used to enable the third kinematic pair (4) to achieve a rotation range of 180° during the rotation process when the third kinematic pair (4) is provided with a femoral stem; The depths of the first notch (311) and the third notch (313) are arranged on the same horizontal plane, so that the rotation of the femoral stem reaches 180°.

6. The three-motion acetabular prosthesis implant according to claim 4, characterized in that: A first inner kinematic pair groove (221) matching the second outer kinematic pair (31) is provided in the first inner kinematic pair (22), and the second outer kinematic pair (31) engages with the first inner kinematic pair groove (221) to achieve the degree of freedom of rotation of the femur relative to the acetabulum.

7. The three-motion acetabular prosthesis implant according to claim 6, characterized in that: The main body motion pair (1) is composed of a main body external motion pair (11) and a main body internal motion pair (12), wherein the main body external motion pair (11) refers to the outer surface of the main body motion pair (1), and the main body internal motion pair (12) refers to the inner surface of the main body motion pair (1). The main body inner motion pair (12) is provided with a main body inner motion pair groove (121) that matches the first outer motion pair (21), and the first outer motion pair (21) engages with the main body inner motion pair groove (121) to achieve the freedom of the femur to move forward and backward relative to the acetabulum.

8. The three-motion acetabular prosthesis implant according to claim 7, characterized in that: An assembly positioning groove (111) is provided on the main body outer motion pair (11), and the assembly positioning groove (111) is provided on the central axis of the main body outer motion pair (1) and is located at the top end of the main body outer motion pair (11).

9. The three-motion acetabular prosthesis implant according to claim 8, characterized in that: The outer motion pair (11) of the main body is also provided with a plurality of assembly ring grooves (112). The assembly ring grooves (112) are arranged around the outer motion pair (11) of the main body. The assembly ring grooves (112) are composed of three groups of ring grooves with an equal distance of 5 mm. Starting from the assembly positioning groove (111) from top to bottom, the cross-section of each assembly ring groove (112) is a circle with a radius of 0.6 mm, 0.8 mm, and 1 mm respectively.

Images