Three-acting acetabular prosthesis implant

Abstract

The invention relates to a three-action type acetabulum prosthesis implant which comprises a main body kinematic pair, a first kinematic pair, a second kinematic pair and a third kinematic pair which are sequentially meshed, the main body kinematic pair is fixed in an acetabulum, the third kinematic pair is coupled with a femoral stem head, and the freedom degree of front-back, rotation and lateral movement of a femur relative to the acetabulum is achieved. Compared with the prior art, the three-action type acetabular prosthesis implant copies a natural anatomical structure of a hip joint, the three-action type acetabular prosthesis implant forms a ball-and-socket joint and has three degrees of freedom which are the same as those of a natural hip joint, and front-back, rotating and lateral movement is achieved through movement of each kinematic pair. According to the three-acting acetabular prosthesis implant, the movement range of the three-acting acetabular prosthesis implant is greatly enlarged through cooperation of the four parts. The tri-acting acetabular prosthetic implants provided herein include, but are not limited to, use to replace the hip joint of a patient.

Description

Technical Field

[0001] The 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 the process of fixing an artificial prosthesis, including the femoral part and the acetabulum part, to normal bone using bone cement and screws to replace the diseased joint.

[0003] The natural anatomy of the hip joint is based on a ball-and-socket joint, with the "ball" being the head of the femur or thigh bone and the "socket" being the acetabulum of 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 in the direction of twisting the leg 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 to avoid an obstacle.

[0004] The traditional acetabular cup connection method is through a ball-and-socket structure. After the ball head is matched with the femoral stem, the movement of the hip joint is achieved by rotating the ball head. However, this movement mechanism greatly limits the patient's movement ability after the prosthesis is implanted. The patient cannot do large-scale hip joint movements such as squats, which will lead to a series of problems such as implant detachment.

[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 fixed to the patient's acetabulum by any suitable method (including bone cement, screws and / or bone growth inducing materials). The configuration of the known femoral head component is similar to that of the natural femoral head. It is known that the component extending from the femoral head is a femoral stem that engages with 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, suitable for bonding 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, and they form a ball and socket joint.

[0006] Chinese patent CN104546227A discloses a modular dual-motion acetabular prosthesis, which is designed to solve the high risk of hip dislocation caused by developmental hip dysplasia, bone loss, joint or soft tissue relaxation, etc.; it includes a metal acetabular outer cup, a metal liner, a polyethylene liner and a metal ball head connected to a femoral stem; the metal acetabular outer cup is fixed by press-fitting and assisted by acetabular screws to enhance the initial mechanical stability of the acetabular prosthesis until the metal acetabular outer cup is biologically fixed; the metal liner and the metal acetabular outer cup are locked by taper fitting, and the ridge on the end face of the metal liner is placed in the groove of the metal acetabular outer cup to prevent the metal liner from rotating in the metal acetabular outer 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 the 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 the patient to have a larger angle of motion after implantation, but it does not enable the patient 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. They form a ball-and-socket joint with the same three degrees of freedom as the natural hip joint, and the front-back, rotational and lateral movements are achieved 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 which are meshed in sequence. 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 forward and backward, rotate and laterally relative to the acetabulum.

[0010] Further, the third kinematic pair is composed of a third outer kinematic pair and a third inner kinematic pair, 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 kinematic pair is provided with a third inner kinematic pair groove matching the femoral stem head, and the femoral stem head is rigidly coupled to the third inner kinematic pair groove.

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

[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 an outer surface of the second kinematic pair, and the second inner kinematic pair refers to an 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] Thereby, after the second kinematic joint and the third kinematic joint are assembled, the third kinematic joint can rotate within the second kinematic joint, so that the prosthesis can move laterally (abduction / adduction), which mainly occurs when the leg is swung sideways, such as when the leg is extended to maintain balance or bypass an obstacle.

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

[0018] The vertical projection surface shape of the second notch is the same as the vertical projection surface shape of the third kinematic pair and the size matches, and the second notch enables the third kinematic pair to enter the second kinematic pair from the lower end of the central axis of the second kinematic pair in a vertical direction;

[0019] The third notch is arranged 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 third kinematic pair is provided with a femoral stem;

[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° lateral movement after assembly.

[0022] Furthermore, in the above, the cross-sections 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 an outer surface of the first kinematic pair, and the first inner kinematic pair refers to an 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] Thereby, after the first kinematic pair and the second kinematic pair are assembled, the second kinematic pair can rotate within the first kinematic pair, so as to achieve the purpose that the three-motion acetabular prosthetic implant can perform rotational movement (medial / lateral rotation), which mainly occurs when the leg is twisted relative to the direction of the trunk, 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 kinematic 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 kinematic pair, the first rotating pair, the first fixed groove and the first enveloping pair constitute a train wheel structure, and the first kinematic pair is stably and directional rotated in the main kinematic pair through the circular disc structure on the side of the first rotating 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 rotation 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 matching the first outer motion pair, and the first outer motion pair is engaged with the main body inner motion pair groove to realize 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's internal kinematic pair, allowing the first kinematic pair to rotate within the main body's internal 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 forward and backward, such as walking, running or kicking a ball.

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

[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 ensures that the main motion pair will not have the risk of loosening, rotating or other displacements after implantation and assembly. The unique large-to-small slot design of the assembly positioning groove makes the geometry of the assembly positioning groove simple and clear, ensuring that the physician can easily and correctly determine the positioning direction of the implant during surgery, ensuring a safe and reliable implantation process during surgery, 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 accuracy 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, the assembly ring grooves are arranged around the outer moving pair of the main body, and 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, and the cross-section of each of the assembly ring grooves 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 with the implantation 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, and during the doctor's implantation process, 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 will be received, which reduces the surgical risks such as implantation failure and positioning errors, and provides protection for the safety of patients.

[0039] As a preferred technical solution, the shape and size of the main motion pair match the acetabulum of the patient, 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 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, which reduces 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 exercises a large range of motion in daily life, and the head of the femoral stem will not collide with the acetabular prosthesis due to a large rotation angle. The maximum opening angle of each kinematic pair is the same, which ensures that each kinematic pair will not collide with the femoral stem when the femoral stem rotates, which reduces the risk of dislocation or collision of the acetabular prosthesis implant due to the patient's 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 head of the femoral stem 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; the ceramic material can be aluminum oxide (AI2O3), zirconium oxide (ZrC>2) or any suitable technical ceramic material. Polymer materials are used alternately with metal or ceramic materials, and they can show excellent wear resistance when friction occurs.

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

[0046] In the present invention, Fig.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 to design 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 and directional.

[0047] like Fig.10 As shown, the first outer kinematic pair is composed 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 by the main kinematic pair. Fig.26 It is a symmetrical train wheel structure. At this time, 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 caused by wear of the prosthetic implant after a long period of friction, which causes the moving pair to shake or shift in the main pair; the first envelope 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 envelope 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 envelope pair allows the second moving pair to enter horizontally and cooperate with the first inner moving pair through a horizontal opening.

[0048] like Fig.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 Fig. 22 As shown, the third outer kinematic pair is composed of an enveloping rotation pair and a positioning groove to form a symmetrical train wheel structure. The enveloping rotation pair guides the third kinematic pair to rotate in a directional manner in the second inner kinematic pair through the circular disks on the left and right sides; the positioning groove stabilizes the third kinematic pair in 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 rotation pair allows the femoral stem to enter and cooperate with the third inner kinematic pair through a horizontal opening.

[0050] The head of the femoral stem is rigidly coupled through the third inner kinematic pair groove of the third inner kinematic pair; the third kinematic pair is engaged through the second inner kinematic pair groove of the second inner kinematic pair; the second kinematic pair is engaged through the first inner kinematic pair groove included in the first inner kinematic pair; the first kinematic pair is engaged through the main body inner kinematic pair groove included in the main body inner kinematic pair; the main body kinematic pair fixes the three-motion acetabular prosthesis 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 regarded as an integral kinematic pair. Therefore, the following principle explanation will skip the motion conduction of the femoral stem, because it is not a part of the prosthesis in the present invention.

[0052] The working principle will explain the status of each component when the movement occurs in reverse order. When the 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] When lateral movement (abduction / adduction) occurs, the femoral stem transmits the lateral movement trend to the third kinematic pair. The third kinematic pair is restricted by the groove of the second inner kinematic pair and only allows lateral movement. The third kinematic pair allows about 180° rotation in the groove, that is, lateral movement. The remaining kinematic pair components will not move due to their respective movement restrictions.

[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. 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 the 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 meshing 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 limitation of the grooves that mesh with the third kinematic pair and the second kinematic pair, the forward and backward movement cannot be achieved. Therefore, when the 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 meshes with the groove of the kinematic pair in the main body, it is allowed to move forward and backward. Therefore, when the movement occurs, the first kinematic pair can 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 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 in three degrees of freedom in the acetabulum. 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 swings 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 direction of 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 the leg is extended to maintain balance or bypass an obstacle.

[0058] 2. The three-motion acetabular prosthesis implant provided by the present invention is composed of a main kinematic pair, a first kinematic pair, a second kinematic pair and a third kinematic pair. This design can effectively produce a larger contact area. The existing traditional acetabular prosthesis has one contact surface, and the three-motion acetabular prosthesis implant provided by the present invention contains three contact surfaces, which significantly increases the contact area. Therefore, the same load is applied to the joint with a larger contact surface, resulting in three pairs of surfaces, and the contact pressure value of each pair of surfaces is lower than the pressure value of the ordinary ball and socket joint, thereby effectively reducing the amount of wear generated.

[0059] 3. In the technical solution of the three-motion acetabular prosthesis implant described in the present invention, by making each kinematic pair cooperate with each other, the third kinematic pair cannot rotate with the first kinematic pair during movement, so that it cannot be dislocated through the groove of the first inner kinematic pair. Each kinematic pair can follow this design, so when the prosthesis moves as a whole, each kinematic pair is in a chain state and will not be dislocated due to excessive large-scale movement of other components. Each kinematic pair relies on the movement of the designed groove and has a wide range of movement angles. In this chained movement relationship that does not restrict each other, the risk of dislocation of the prosthesis when used by the patient is greatly reduced.

[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 movements occur, each component will interlock with other components due to the limitations of their respective grooves. This interlocking relationship makes it unnecessary for the first kinematic pair, the second kinematic pair, and the third kinematic pair in the three-motion acetabular prosthetic implant described in the present invention to have any form of attachments or connections. This interlocking relationship reduces the risk of inadvertent dislocation of each component during movement, as each is restricted to move within the corresponding groove. This greatly reduces the possibility of the implant falling off during exercise in patients.

[0061] 5. In the technical solution of the three-motion acetabular prosthesis implant described in the present invention, the unique groove design on the inner side of each kinematic pair, that is, each groove only allows the kinematic pair it is meshing with to move in one direction. For example, the third kinematic pair can only move sideways and cannot move forward and backward independently. In addition, due to the design of the mutual meshing of the kinematic pairs, the size of each component is also different. For example, there is a significant difference in the size of the main kinematic pair and the first kinematic pair. 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 when the doctor is performing surgery, and there will be no mistakes.

[0062] 6. In the technical solution of the three-motion acetabular prosthesis implant described in the present invention, the main kinematic pair, the first kinematic pair, and the second kinematic pair all have an opening in the same direction and position, so that when the patient squats in daily life, the opening allows the acetabular prosthesis to move without the risk of dislocation or collision of the femoral stem head connected to the third kinematic pair. This unique opening allows this embodiment to have an intuitive structural correspondence during the installation process, that is, the opening of each component maintains a consistent direction and position. This reduces the possibility of incorrect installation during the installation process.

[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 manner and in sequence. In the installation of 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 It is a schematic structural diagram 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 It is a 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 It is a schematic diagram of the top view structure of the main body kinematic pair in the present invention;

[0070] Figure 7 It is a side view structural diagram of the main body kinematic pair in the present invention;

[0071] Figure 8 It is a front view structural diagram of the main body kinematic pair in the present invention;

[0072] Fig. 9 It is a bottom view structural schematic diagram of the first kinematic pair in the present invention;

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

[0074] Fig.11 is a schematic side view of the structure of the first kinematic pair in the present invention;

[0075] Fig.12 It is a front view structural schematic diagram of the first kinematic pair in the present invention;

[0076] Fig.13 is a schematic diagram of the overall structure of the second kinematic pair in the present invention;

[0077] Fig.14 is a schematic side view of the structure of the second kinematic pair in the present invention;

[0078] Fig.15 is a schematic diagram of the top view of the second kinematic pair in the present invention;

[0079] Fig.16 is a front view structural schematic diagram of the second kinematic pair in the present invention;

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

[0081] Fig.18 for Fig.17 A partial enlarged view of the shaded part;

[0082] Fig.19 It is a schematic diagram of the coordinated use of the second kinematic pair, the third kinematic pair and the femoral stem in the present invention;

[0083] Fig. 20 is a front view structural schematic diagram of the third kinematic pair in the present invention;

[0084] Fig.21 is a schematic side view of the structure of the third kinematic pair in the present invention;

[0085] Fig. 22 is a schematic diagram of the overall structure of the third kinematic pair in the present invention;

[0086] Fig.23 It is a schematic diagram of the overall structure of the femoral stem in the present invention;

[0087] Fig.24 It is a schematic diagram of the use of the femoral stem and the three-motion acetabular prosthesis implant in the present invention;

[0088] Fig.25 It is a structural schematic diagram of a train wheel in the working principle of the present invention;

[0089] Fig.26 It is a schematic structural 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 enveloping 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 enveloping 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 in conjunction with 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, further definition and explanation thereof is not required in subsequent drawings.

[0093] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0094] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0095] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. 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 kinematic pair 1, a first kinematic pair 2, a second kinematic pair 3 and a third kinematic pair 4 that are engaged in sequence, 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 achieve 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 kinematic pair 42 is provided with a third inner kinematic pair groove 421 matching the femoral stem head 5, and the femoral stem head 5 is rigidly coupled to the third inner kinematic pair groove 421.

[0100] After coupling, the femoral stem head 5 and the third kinematic pair 4 can be regarded as an integral and inseparable 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, and the third outer kinematic pair 41 is engaged with the second inner kinematic pair groove 321 to realize the freedom of lateral movement of the femur relative to the acetabulum.

[0104] Thereby, after the second kinematic joint 3 and the third kinematic joint 4 are assembled, the third kinematic joint 4 can rotate inside the second kinematic joint 3, so as to achieve the purpose of the prosthesis being able to move laterally in abduction / adduction, which mainly occurs when the leg is swung sideways, such as when the leg is extended 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 arranged 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;

[0108] 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°.

[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° 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, and the second outer kinematic pair 31 is engaged with the first inner kinematic pair groove 221 to realize the freedom of rotation of the femur relative to the acetabulum.

[0113] Thereby, after the first kinematic joint 2 and the second kinematic joint 3 are assembled, the second kinematic joint 3 can rotate within the first kinematic joint 2, so as to achieve the purpose that the three-motion acetabular prosthesis implant can rotate medially / laterally, which mainly occurs when the leg is twisted relative to the direction of the trunk, 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 disk structure on the side of the first rotating pair 211, the first kinematic pair 2 can be stably and directional rotated 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 kinematic pair 12 is provided with a main body inner kinematic pair groove 121 matching the first outer kinematic pair 21, and the first outer kinematic pair 21 is engaged with the main body inner kinematic pair groove 121 to realize 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 that the three-motion acetabular prosthesis implant can 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 annular grooves 112 are further provided on the outer moving pair 11 of the main body. The assembly annular grooves 112 are arranged around the outer moving pair 11 of the main body. The assembly annular grooves 112 are composed of three groups of annular grooves with an equal distance of 5 mm. Starting from the assembly positioning groove 111 from top to bottom, the cross-section of each of the assembly annular grooves 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, for example, screws, bone cement, bone growth inducing materials 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 kinematic pair groove 421, the second inner kinematic pair groove 321, the first inner kinematic pair groove 221 and the inner kinematic pair groove 121 of the main body are the same. This opening design allows the third kinematic pair 4 to be assembled in a vertical direction, the second kinematic pair 3 to be assembled in a horizontal direction, and the first kinematic pair 2 to be assembled in a vertical direction. Each adjacent kinematic pair is assembled in a different direction, which reduces the risk of dislocation of each kinematic pair when the patient moves in daily life. The opening design also takes into account the situation that the patient moves a lot in daily life, and the femoral stem head 5 will not collide with the acetabular prosthesis due to a large rotation angle. The maximum opening angle of each kinematic pair is the same, which ensures that each kinematic pair will not collide with the femoral stem when the femoral stem rotates, which reduces the risk of dislocation or collision of the acetabular prosthesis implant due to the patient's movement in daily life. When the patient squats in daily life, the opening allows the three-motion acetabular prosthesis implant to move, and the femoral stem head 5 connected to the third kinematic pair 4 will not be dislocated or collided.

[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 joint 1, the first kinematic joint 2, the second kinematic joint 3 and the third kinematic joint 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; the ceramic material can be aluminum oxide AI2O3, 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 show excellent wear resistance when friction occurs.

[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 Figure 23 to Figure 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, so that the movement of the femoral stem is driven by the movement of the human thigh and 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 a 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. Figure 23 to Figure 24 Designed for conventional femoral stem structures, such as Fig.23 It is a conventional femoral stem design, the tip of which is implanted in the human femur, and the other end of the femoral stem head 5 structure is combined with the third inner kinematic pair groove 421. The femoral stem head 5 and the third inner kinematic pair groove 421 are pressed together to achieve rigid coupling, so in the process of motion trend transmission, in this embodiment, the femoral stem head 5 and the third kinematic pair 4 can be temporarily regarded as a linked integral part, so as to simplify but not ambiguously explain the working principle. Fig.24 This is the positional relationship between the femoral stem and the third kinematic pair 4 when they are 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 to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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-motion 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 meshed in sequence. The main kinematic pair (1) is fixed in the acetabulum, and the third kinematic pair (4) is coupled with a femoral stem head (5) to realize the freedom of the femur to move forward and backward, rotate and laterally relative to the acetabulum.

2. A 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). The third inner kinematic pair (42) is provided with a third inner kinematic pair groove (421) matching the femoral stem head (5), and the femoral stem head (5) is rigidly coupled to the third inner kinematic pair groove (421).

3. A 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) is engaged with the second inner kinematic pair groove (321) to realize the 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 the same as the vertical projection surface shape of the third kinematic pair (4) and the size is matched, 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 arranged 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: 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 inner kinematic pair (22) is provided with a first inner kinematic pair groove (221) matching the second outer kinematic pair (31), and the second outer kinematic pair (31) is meshed 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 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) form a train wheel structure; through the circular disc structure on the side of the first rotating pair (211), the first kinematic pair (2) can be stably and directional rotated in the main kinematic pair (1).

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

9. The three-motion acetabular prosthesis implant according to claim 8, characterized in that: The main body outer motion pair (11) is provided with an assembly positioning groove (111), and the assembly positioning groove (111) is arranged 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).

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

Images