CN109464226B

CN109464226B - Silicon nitride ceramic artificial knee joint

Info

Publication number: CN109464226B
Application number: CN201711177602.4A
Authority: CN
Inventors: 丁华丹
Original assignee: Suzhou Spade Medical Technology Co ltd
Current assignee: Suzhou spade Medical Technology Co.,Ltd.
Priority date: 2017-09-08
Filing date: 2017-11-22
Publication date: 2021-09-17
Anticipated expiration: 2037-11-22
Also published as: CN109464226A

Abstract

The invention discloses a silicon nitride ceramic artificial knee joint, which consists of an artificial femoral condyle, an artificial tibial plateau and an artificial patella and relates to the technical field of artificial joints. The artificial femoral condyle, the artificial tibial plateau and the artificial patella are all made of silicon nitride ceramic materials, and the silicon nitride ceramic artificial knee joint has various excellent performances of a biological ceramic implant, high hardness, high bending strength, high fatigue strength, high fracture toughness, excellent friction performance, good bone length and bone growth capacity, good anti-infection capacity and good developability, and can solve the problems of abrasion and stress shielding of the artificial knee joint.

Description

Silicon nitride ceramic artificial knee joint

Technical Field

The invention relates to the technical field of artificial joints, in particular to a silicon nitride ceramic artificial knee joint.

Background

The knee joint is the largest joint of the human body and consists of the distal part of the femur (femur), the proximal end of the tibia, and the patella (patella) in front of the knee joint, covered externally with tough tendons. The knee joint is also an important load bearing joint of a human body, the main function is stretching and bending activities, and the size of the stretching and bending activity range of the knee joint directly influences the daily life of people.

However, diseases such as osteoarthritis, rheumatoid arthritis, traumatic arthritis, etc. cause pain in the knee joint and loss of its function, thereby seriously affecting the life of patients. Currently, artificial knee joint replacement surgery has become an effective means for treating knee joint diseases. However, the inventor of the present application found in a long-term research and development process that most of the existing artificial knee joints are made of metal materials or polymer materials, and have a major wear problem in clinical applications, for example, wear occurs between a metal femoral condyle and a polyethylene liner, between a polyethylene liner and a metal tibial plateau, or between a plastic patella and a metal femoral condyle, and generates wear debris particles; these less worn individuals can lead to osteolysis, aseptic loosening and infection of the prosthesis, and, more so, failure of the prosthesis. In addition, due to the difference of material characteristics between the metal material and the human native bone, stress shielding can occur during clinical application, and the existence of the stress shielding can cause a series of problems such as osteolysis and the like, thereby shortening the service life of the prosthesis.

Disclosure of Invention

The invention mainly solves the technical problem of providing a silicon nitride ceramic artificial knee joint which can improve the problems of abrasion and stress shielding of the artificial knee joint.

In order to solve the technical problems, the invention adopts a technical scheme that: the artificial femoral condyle comprises a medial condyle and a lateral condyle, wherein the medial condyle and the lateral condyle are respectively provided with mutually independent spherical areas at the distal ends and are connected with each other at the proximal ends to form a connecting area, the middle of the connecting area is sunken to form a patella pulley groove, the patella pulley groove is used for accommodating a patella, and the material of the femoral condyle is silicon nitride ceramic.

In order to solve the technical problem, the invention adopts another technical scheme that: an artificial tibial plateau is provided, the tibial plateau including a lower surface for contacting a human tibia to form a fixed connection, an upper surface for contacting a femoral condyle to form a tibiofemoral articulating friction pair, and a concave anterior surface for contacting a patella to form the friction pair, the tibial plateau being formed of a silicon nitride ceramic.

In order to solve the technical problem, the invention adopts another technical scheme that: providing an artificial patella, wherein the patella is an ovoid, and comprises a connecting mechanism for fixedly connecting with an original patella of a human body and an outer peripheral surface for contacting with a femoral condyle and a tibial plateau to form a joint movable friction pair, the connecting mechanism is arranged on the bottom surface of the ovoid, and the outer peripheral surface corresponds to the spherical surface of the ovoid; the material of the patella is silicon nitride ceramic.

The invention has the beneficial effects that: compared with the existing ceramic materials, high polymer materials and metal materials, the silicon nitride ceramic artificial knee joint has the excellent performances of a biological ceramic implant, high hardness, high bending strength, high fatigue strength, high fracture toughness, excellent friction performance, good bone length and bone length insertion capacity, good ageing resistance, good anti-infection capacity and good developing performance, and can improve the problems of abrasion and stress shielding of the artificial knee joint.

Drawings

FIG. 1 is a schematic view of the components of an artificial knee joint;

FIG. 2 is a schematic view of a coronal plane of an embodiment of an artificial femoral condyle of the present application;

FIG. 3a is a schematic view of an embodiment of an artificial femoral condyle of the present application in a coronal plane;

FIG. 3b is a schematic view of an embodiment of an artificial femoral condyle of the present application in the sagittal plane;

FIG. 4 is a schematic view of the coronal plane of an embodiment of an artificial femoral condyle of the present application;

FIG. 5 is a schematic view of an embodiment of an artificial femoral condyle according to the present application shown in cross-section at 90 ° of knee flexion;

FIG. 6 is a schematic view of an embodiment of an artificial femoral condyle according to the present application on the coronal plane of a 90 ° knee flexion;

FIG. 7 is a schematic view of an embodiment of an artificial femoral condyle according to the present application shown in cross-section at 0 ° flexion;

FIG. 8a is a schematic view of an embodiment of an artificial femoral condyle of the present application;

FIG. 8b is a schematic view of an embodiment of an artificial femoral condyle of the present application;

FIG. 9 is a schematic view of an embodiment of an artificial femoral condyle according to the present application shown in cross-section at 0 ° flexion;

FIG. 10 is a schematic view in the sagittal plane of an embodiment of the artificial femoral condyle of the present application;

FIG. 11 is a schematic structural view of an embodiment of the artificial tibial plateau of the present application;

FIG. 12a is a schematic view of an embodiment of an artificial tibial plateau and artificial femoral condyle combination of the present application in the sagittal plane;

FIG. 12b is a schematic view of an embodiment of the present invention in combination with an artificial tibial plateau and an artificial femoral condyle on the coronal plane;

FIG. 13a is a schematic cross-sectional view along direction AA in FIG. 12 a;

FIG. 13b is a schematic cross-sectional view of FIG. 12b along the BB and CC directions, respectively;

FIG. 14 is a schematic view of an active configuration of an embodiment of the upper surface of the artificial tibial plateau of the present application in the sagittal plane;

FIG. 15 is a schematic view of an embodiment of an artificial knee joint of the present application;

FIG. 16 is a schematic view of a structure of an embodiment of the artificial patella of the present application;

FIG. 17 is a schematic view of an embodiment of the present application in combination with an artificial patella and an artificial femoral condyle;

FIG. 18 is a schematic view of an embodiment of the present application of an artificial patella in combination with an artificial femoral condyle during flexion and extension.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples.

The artificial femoral condyle, the artificial tibial plateau and the artificial patella provided by the application belong to the technical field of biological medical treatment, and a plurality of anatomical terms are used in the structural description or the effect description, and are only used for clearly describing the structural characteristics and cannot bring limitation to the application.

Specifically, the basic anatomical poses are: the body is upright, the eyes look at the front, the two feet are closed, and the toe points are forward; the upper limbs are perpendicular to the two sides of the trunk, and the palms face to the front (the thumbs are on the outer sides); explaining directions of all parts based on a basic anatomical posture, wherein the head is on the top, the feet are on the bottom, the proximal head side is the upper end, and the distal head side is the lower end; the relationship between the common ends and the far ends of the limbs is described, that is, the root part close to the trunk is the proximal end, and the part relatively far away or the tail end is the far end; front and back, with the front facing the abdomen and the back facing the abdomen; the medial and lateral sides are the medial side, the side closer to the midline, and the lateral side, the side relatively far from the midline, wherein the tibia and fibula are juxtaposed in the lower leg, the tibia is medial and the fibula is lateral, so the sides of the tibia and fibula can be called as the medial side and the lateral side.

Based on the basic anatomical posture, the human body can be provided with three typical mutually vertical axes, wherein the sagittal axis is a horizontal line in the front-back direction; the coronal (frontal) axis is a horizontal line in the left-right direction; the vertical axis is a vertical line which is vertical to the horizontal line in the vertical direction. The human body or organs can be cut into different sections according to the axis, the sagittal plane is a vertical section made along the sagittal axis direction and is a longitudinal section which divides the human body into a left part and a right part; the coronal plane is a vertical section made along the coronal axis and is a longitudinal section dividing the human body into a front part and a rear part; the horizontal plane or the cross section is a horizontal cross section made along a horizontal line, and divides the human body into an upper part and a lower part which are vertical to the two longitudinal sections.

The knee joint is the largest joint of the human body and consists of the distal part of the femur (femur), the proximal end of the tibia, and the patella (patella) in front of the knee joint, covered externally with tough tendons. The distal femur bulges bilaterally as if the two spheres come together, referred to as the medial and lateral condyles, respectively. A concave groove is arranged between the two condyles and is called a patellar pulley, and when the knee joint is stretched and bent, the patella (patella) slides up and down in the groove to form a patellar-femoral joint. The proximal end of the tibia is high in the middle and flat on both sides, and is called the medial and lateral tibial plateau. The inner and outer condyles of the femur form a joint movable friction pair with the inner and outer platforms of the tibia respectively. In general, the knee joint comprises three bones forming two articular surfaces (patellofemoral and tibiofemoral).

Accordingly, the artificial knee joint is also composed of a plurality of components. Referring to fig. 1, fig. 1 is a schematic structural view of each component of the artificial knee joint. These artificial products, which are implanted into the human body to function, are commonly referred to medically as "prostheses". The artificial knee joint comprises three parts: a femoral condyle prosthesis 101, a tibial prosthesis 102, and a patellar prosthesis 103, wherein the tibial prosthesis 102 may be comprised of a tibial plateau shim 1021 and a tibial plateau 1022.

The existing artificial femoral condyle is generally made of a metal material, and due to the difference of material characteristics between the metal material and the human native bone, a stress shielding phenomenon can occur in clinical application, so that a series of problems such as osteolysis and the like can be caused by the existence of the stress shielding, and the service life of the prosthesis is shortened. On the basis, the application provides an artificial femoral condyle which is made of a silicon nitride ceramic material.

Specifically, please refer to fig. 2, fig. 2 is a schematic structural diagram of an embodiment of the artificial femoral condyle of the present application on the coronal plane. In one embodiment, the femoral condyle 20 includes a medial condyle 201 and a lateral condyle 202, the medial condyle 201 and the lateral condyle 202 are formed with separate

spherical areas

2011 and 2021 at distal ends, respectively, and are joined to each other at proximal ends to form a joining area, a medial concavity of the joining area forms a patellar trochlear groove 203, the patellar trochlear groove 203 is used for receiving a patella, wherein the material of the femoral condyle 20 is silicon nitride ceramic.

The artificial femoral condyle 20 provided by the embodiment is made of a silicon nitride ceramic material, and compared with the existing ceramic femoral condyle and metal femoral condyle, the artificial femoral condyle has various excellent performances of a biological ceramic implant, and also has high hardness, high bending strength, high fatigue strength, high fracture toughness, excellent friction performance, good bone length and bone growth capacity, good ageing resistance, good anti-infection capacity and good developing performance, and can improve the problems of abrasion and stress shielding of the artificial femoral condyle.

Referring to fig. 3a and 3b, fig. 3a is a schematic view of an embodiment of an artificial femoral condyle of the present application in a coronal plane, and fig. 3b is a schematic view of an embodiment of an artificial femoral condyle of the present application in a sagittal plane. In one embodiment, the bulbous regions 2011 of the medial condyle 201 and the bulbous regions 2021 of the lateral condyle 202 have the same single spherical radius in the coronal and sagittal planes. By providing the spherical zone 2011 of the medial condyle 201 and the spherical zone 2021 of the lateral condyle 202 with the same single spherical diameter in the coronal plane and the sagittal plane, the tension of the soft tissue around the knee joint during flexion can be kept constant, thereby improving the stability of the knee joint.

With continued reference to fig. 2, in one embodiment, a constriction region 204 is formed at the transition position from the spherical region 2011 of the medial condyle 201 to the connection region, and the constriction region 204 can ensure good stability and contact area of the artificial patella in contact therewith, and can also reduce the pain in the anterior knee and reduce the soft tissue interference phenomenon during hyperextension of the knee joint.

Referring to fig. 4, fig. 4 is a schematic view of a coronal plane of an embodiment of an artificial femoral condyle of the present application. In one embodiment, the patellar trochlear groove 203 is inclined 3 to 8 degrees, e.g., 5 degrees, 7 degrees, etc., to the lateral condyle 202 side with respect to the sagittal axis, thereby reducing tension in the lateral support band and reducing unnecessary excessive soft tissue loosening.

Referring to FIG. 5, FIG. 5 is a schematic view of an artificial femoral condyle according to an embodiment of the present invention shown in a 90 ° flexed knee cross section. The present embodiment provides a femoral condyle 502 having a patellar trochlear groove depth that is closer to the native human patellar trochlear groove depth. As shown in fig. 5, 501 is a human native femoral condyle, 502 is a femoral condyle provided in the present embodiment, and 503 is a femoral condyle made by other methods; the depth of the patellar trochlear groove of the femoral condyle 502 is set to be closer to the depth of the native patellar trochlear groove of the human body, so that the excessive filling can be reduced, and the artificial knee joint can operate more bionically.

Referring to fig. 6, fig. 6 is a schematic view of an artificial femoral condyle according to an embodiment of the present invention on a 90 ° coronal plane of a knee flexion. The present embodiment provides a femoral condyle 601 with the patellar trochlear groove extending distally longer. As shown in fig. 6, 601 is a femoral condyle provided in the present embodiment, and 602 is a femoral condyle made by other methods; by extending the patellar trochlear groove of the femoral condyle 601 to the distal end, when the knee joint is highly flexed, the patella still can keep a sufficient contact area with the femoral condyle, so that the occurrence of patellofemoral syndrome is remarkably reduced.

Referring to FIG. 7, FIG. 7 is a schematic view of an artificial femoral condyle according to an embodiment of the present invention shown in a cross-section of a knee at 0 °. In the present embodiment, the highest point of the lateral condyle 202 is higher than the bottom surface of the patella trochlear groove 203 by 2 to 6mm, for example, 3mm, 5mm or the like on the side of the joint region, and this makes it possible to provide a good patella track, and in particular, to prevent lateral dislocation of the patella at the early stage of knee joint flexion.

Referring to fig. 8 and 9, fig. 8a is a schematic structural view of an embodiment of the artificial femoral condyle of the present application, fig. 8b is a schematic structural view of an embodiment of the artificial femoral condyle of the present application, and fig. 9 is a schematic structural view of an embodiment of the artificial femoral condyle of the present application on a 0 ° flexion cross section. In this embodiment, the posterior surface of the patellar trochlear groove has a first end surface 801, a second end surface 802, and a third end surface 803, and the posterior surface of the medial condyle spherical region has a fourth end surface 804, a fifth end surface 805; the posterior surface of the lateral condyle spherical region has a sixth end surface 806 and a seventh end surface 807, wherein the lateral edge of the lateral condyle has a sagittal axis as a reference, and the second end surface 802 contracts 8-16 degrees, such as 10 degrees, 12 degrees, 14 degrees and the like, towards the lateral condyle side, and the lateral edge of the medial condyle has a sagittal axis as a reference, and contracts 16-24 degrees, such as 18 degrees, 20 degrees, 22 degrees and the like, towards the lateral condyle side, in such a way, the interference of the femoral condyle 20 with the soft tissues on both sides of the knee joint can be reduced.

Referring to fig. 8 and 10, fig. 10 is a schematic view of an embodiment of the artificial femoral condyle of the present application in the sagittal plane. In the present embodiment, the included angle between the first end surface 801 and the projection of the fifth end surface 805/the seventh end surface 807 on the sagittal plane is 6 degrees, so that excessive cutting of the anterior cortical bone of the femur during the operation can be avoided.

The projection of the acute angle between the second end surface 802 and the third end surface 803 on the sagittal plane is 45 degrees, and the projection of the acute angle between the third end surface 803 and the fourth end surface 804/sixth end surface 806 on the sagittal plane is also 45 degrees, so that the ideal contact stress area between the artificial femoral condyle and the native femur can be ensured, and the quick operation of the operation is facilitated.

In clinical application, for a traditional metal implant, two ways of forming biological fixation are generally available, one is to use bone cement as a fixing medium, but the bone cement itself brings many problems, such as grinding particles, bonding reliability between raw bone and bone cement, bonding reliability between bone cement and metal implant, chemical heat release, coating of cement sheath, generation and distribution, stress shielding, removal during revision, and the like, which all increase the risk of operation failure. The other fixing mode is that bone cement is not used, generally, the roughness of the surface of the implant can be increased, such as plasma titanium slurry spraying, so that osteoblasts can grow on bones as soon as possible to form reliable biological fixation, a native trabecular bone structure of a human body can be simulated, a similar porous structure, such as a tantalum metal trabecular bone, is constructed on the surface of the implant, and a hydroxyapatite coating and the like are used for inducing the osteoblasts to grow in, so that good biological fixation is formed. In this way, space can be reserved for the later revision surgery, which is particularly suitable for young and active patients, but the bonding between the two different metals of the coating and the implant itself still presents reliability problems.

Based on this, the surface of the femoral condyle, which is in contact with the native femur, is provided with the porous rough structure, so that on one hand, the roughness of the contact surface can be increased, and osteoblasts can be helped to grow on the bone as soon as possible; on the other hand, the porous rough structure is similar to the native trabecular bone structure of a human body, and can induce osteoblast bone to grow in, so that the artificial femoral condyle and the native femur are effectively and fixedly connected to form good biological fixation. Wherein the average porosity of the porous rough structure is 30-70%, the average pore diameter is 100-1000 microns, and the average void intercept is 500-1500 microns.

In an embodiment, the femoral condyle is smooth on the surface which is not contacted with the native femur, namely the femoral condyle is smooth on the surface which is contacted with the tibial plateau and the patella, and the wear among all the components can be reduced and the service life of the prosthesis can be prolonged by setting the femoral condyle to be the smooth surface. Wherein the roughness value Ra of the smooth surface is 0.01-1.6 microns.

On this basis, this application still provides silicon nitride ceramic material's artifical tibial plateau and artifical patella, because of silicon nitride ceramic material's good performance, silicon nitride ceramic material's tibial plateau and patella all have good performance.

Specifically, please refer to fig. 11, fig. 11 is a schematic structural diagram of an embodiment of the artificial tibial plateau of the present application. In this embodiment, the tibial plateau 110 includes a lower surface 1101 for contacting the human tibia to form a fixed connection, an upper surface 1102 for contacting the femoral condyle to form a tibiofemoral joint, and a concave anterior surface 1103 for contacting the patella to form a friction pair, the material of the tibial plateau 110 being a silicon nitride ceramic. The tibial plateau 110 provided in this embodiment has corresponding properties of silicon nitride ceramics, and please refer to the description of the above embodiment for details, which are not described herein.

With continuing reference to fig. 11 and with reference to fig. 12, 13 and 14, fig. 12a is a schematic view of an embodiment of the present invention of an artificial tibial plateau and artificial femoral condyle in a sagittal plane, fig. 12b is a schematic view of an embodiment of the present invention of an artificial tibial plateau and artificial femoral condyle in a coronal plane, and fig. 13a is a schematic view of a cross-section of fig. 12a along direction AA; fig. 13b is a schematic cross-sectional view of fig. 12b along the BB and CC directions, respectively, and fig. 14 is a schematic view of the upper surface of the artificial tibial plateau of the present application in an active configuration along the sagittal plane. In one embodiment, superior surface 1102 of tibial plateau 110 is provided with medial condyle receiving area 11021 and lateral condyle receiving area 11022 for receiving the medial and lateral condyles of the femoral condyle, respectively, wherein medial condyle receiving area 11021 and lateral condyle receiving area 11022 have the same single spherical diameter in the coronal and sagittal planes. The medial condyle receiving area 11021 is ball and socket shaped to receive the medial condyle of the ball to form a limited active friction pair; the lateral condyle receiving area 11022 is shaped as a concave saddle for coupling to receive the spherical lateral femoral condyle, thereby forming a lower restriction, movable friction pair than the medial side, such that the medial femoral condyle can move in situ on the medial receiving area 11021 of the tibial plateau as the knee joint moves from extension to flexion, and the lateral femoral condyle can follow the lateral receiving area 11022 of the tibial plateau by 10-25 degrees around the medial condyle as the knee is flexed.

Meanwhile, by the mode, the tibial plateau 110 and the femoral condyle have the largest contact area, particularly the medial condyle part forms a friction pair similar to a spherical hinge, the contact stress is reduced, the abrasion is reduced, the medial high stability of the knee joint is ensured, and the problem of moderate buckling instability is solved.

In one embodiment, the lower surface 1101 is a porous roughness structure, wherein the porous roughness structure has an average porosity of 30% to 70%, an average pore size of 100 to 1000 microns, and an average void intercept of 500 to 1500 microns. By providing a porous rough structure, the lower surface 1101 can have good bone in-growth and bone in-growth performance, thereby effectively fixedly connecting the tibial plateau 110 with the native tibia to form good biological fixation. For details of the principle, please refer to the description of the above embodiments, which is not repeated herein.

In one embodiment, the upper surface 1102 and the front surface 1103 are smooth surfaces having a roughness value Ra in the range of 0.01 to 1.6 microns; since the upper surface 1102 is used for contacting with the femoral condyle to form a tibia-femur movable friction pair, and the front surface 1103 is used for contacting with the patella to form a knee movable friction pair, abrasion is easily caused during the joint movement, so that the upper surface 1102 and the front surface 1103 are provided with smooth surfaces with extremely low roughness, the abrasion between the tibial plateau 110 and the femoral condyle can be reduced, and the service life of the prosthesis can be prolonged.

Further, referring to fig. 15, fig. 15 is a schematic structural diagram of an embodiment of the artificial knee joint of the present application, and the upper surface of the artificial tibial plateau 1501 provided in the present embodiment is a smooth surface, so that the artificial tibial plateau 1501 can be directly used in cooperation with the artificial femoral condyle 1502 and the artificial patella 1503 without using a tibial plateau liner in clinical application. Through this kind of mode, not only can reduce the wearing and tearing between current tibial plateau gasket and the tibial plateau, can also simplify the operation procedure, shorten the operation time.

Referring to fig. 16, fig. 16 is a schematic structural view of an embodiment of the artificial patella of the present application. In this embodiment, the patella 160 is an ovoid, and includes a connection structure 1601 for fixedly connecting with an original patella of a human body and an outer circumferential surface 1602 for contacting with a femoral condyle and a tibial plateau to form a joint movable friction pair, wherein the connection structure 1601 is disposed on a bottom surface of the ovoid, and the outer circumferential surface 1602 corresponds to a spherical surface of the ovoid; the material of the patella 160 is silicon nitride ceramic. The patella 160 provided in this embodiment has corresponding properties of silicon nitride ceramics, and please refer to the description of the above embodiment for details, which are not described herein again.

Referring to fig. 17 and 18, fig. 17 is a schematic structural view of an embodiment of the artificial patella and artificial femoral condyle combination of the present application, and fig. 18 is a schematic structural view of an embodiment of the artificial patella and artificial femoral condyle combination of the present application during flexion and extension. In this embodiment, the outer peripheral surface 1602 is used to contact the patella sliding groove of the femoral condyle and the anterior surface of the tibial plateau to form a movable joint friction pair, and the outer peripheral surface 1602 and the correspondingly coupled patella sliding groove have the same single spherical diameter, so that the contact area between the patella and the femoral condyle can be maximized, and even if the alignment of the patella is poor, the patella can still maintain good contact and sliding in the sliding groove.

In one embodiment, the edges of the ovoid are rounded in a manner that reduces the problem of interference of the patella 160 with the surrounding soft tissue.

In one embodiment, the coupling mechanism 1601 has three coupling portions, which can enhance the fixation of the patella 160 to the original patella.

In one embodiment, the outer peripheral surface 1602 of the patella 160 is smooth with a roughness value Ra in the range of 0.01-1.6 microns; because the outer peripheral surface 1602 contacts with the femoral condyle and the tibial plateau to form a joint movement friction pair, wear is easily caused in the joint movement process, so that the outer peripheral surface 1602 is set to be a smooth surface with extremely low roughness, the wear between the patella 160 and the femoral condyle and the tibial plateau can be reduced, and the service life of the prosthesis is prolonged.

In one embodiment, the bottom surface of the patella 160 has a porous rough structure, that is, the contact surface between the patella 160 and the native patella is a porous rough structure, and the porous rough structure can make the contact surface between the patella 160 and the native patella have good bone growth performance and bone ingrowth performance, so as to effectively fix and connect the patella 160 and the native patella, thereby forming good biological fixation. For details of the principle, please refer to the description of the above embodiments, which is not repeated herein. Wherein the average porosity of the porous rough structure is 30-70%, the average pore diameter is 100-1000 microns, and the average void intercept is 500-1500 microns.

With continued reference to fig. 15, the present application further provides an artificial knee joint comprising: the artificial femoral condyle, the artificial tibial plateau and the artificial patella have the same technical characteristics as the artificial femoral condyle, the artificial tibial plateau and the artificial patella in the above embodiment, and specific reference is made to the description of the above embodiment, which is not repeated herein.

In one embodiment, the present application also provides a method of making the above-described artificial femoral condyle, artificial tibial plateau, and artificial patella. The specific steps for preparing the artificial femoral condyle are as follows:

the method comprises the following steps: preparing raw material powder, and fully mixing silicon nitride ceramic powder, yttrium oxide and aluminum oxide according to a preset proportion; wherein the silicon nitride ceramic powder accounts for 88 percent of the total weight, and the yttrium oxide and the aluminum oxide account for 12 percent of the total weight.

Step two: and fully ball-milling the mixed raw material powder for 10 hours in a ball mill by using zirconia grinding balls.

Step three: granulating and drying the raw material powder subjected to ball milling through a spray granulator, wherein the specific granulation conditions are as follows: the granulation atmosphere is air, the solid content of the slurry is 45-55%, the rotation speed of the atomizer is 8000 rpm, the feeding rate is 0.4 liter per minute, the drying temperature is 80 ℃, and the drying time is 15 hours.

Step four: placing the granulated and dried raw material powder into a mould for cold press molding to obtain a first green body; wherein the pressure of cold press molding is 30 MPa.

Step five: and carrying out cold isostatic pressing treatment on the first blank to obtain a blank piece.

Step six: and (3) processing the blank piece to obtain a semi-finished product to be sintered by machining and molding according to the shape requirement of the femoral condyle and related technological parameters.

Step seven: sintering for 150 minutes at the temperature of 2200 ℃ under the protection of nitrogen and sintering and pore-forming to obtain the finished product blank of the silicon nitride ceramic femoral condyle.

Step eight: and then carrying out hot isostatic pressing treatment on the silicon nitride ceramic femoral condyle finished product blank, wherein the specific conditions are as follows: the time is 15 hours, the temperature is 2000 ℃, and the pressure is 200 MPa.

Step nine: and (3) carrying out post-pore-forming treatment, polishing treatment, surface pickling treatment, laser marking and proper cleaning on the silicon nitride ceramic femoral condyle finished product blank according to the technical requirements of the finished femoral condyle, and then obtaining the finished femoral condyle.

Similarly, on the basis of the above-mentioned technological steps, the artificial tibial plateau, artificial patella and the like can be prepared by properly adjusting technological parameters.

Above scheme, the artificial knee joint of silicon nitride ceramic that this application provided, it comprises artifical thighbone condyle, artifical tibial plateau and artifical patella, artifical thighbone condyle, artifical tibial plateau and artifical patella all are made by silicon nitride ceramic material, compare current oxide ceramic material, macromolecular material and metal material, it is except having each item excellent property of biological ceramic implant, still has high rigidity, high bending strength, high fatigue strength, high fracture toughness, excellent frictional property, go up with the bone length ability of going into in the good bone length, good ageing resistance, good anti-infective ability, good developing ability, can improve the wearing and tearing and the stress shielding problem of artifical knee joint.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The artificial femoral condyle is characterized by comprising an inner condyle and an outer condyle, wherein the inner condyle and the outer condyle are respectively provided with mutually independent spherical areas at the far ends and are connected with each other at the near ends to form a connection area, the middle of the connection area is sunken to form a patella pulley groove which is used for accommodating a patella, the femoral condyle is made of silicon nitride ceramics, the femoral condyle is integrally formed, the surface of the femoral condyle, which is contacted with a tibial platform and the patella, is a smooth surface, and the roughness Ra of the smooth surface is 0.01-1.6 microns;

wherein the spherical regions of the medial and lateral condyles have the same single spherical radius in the coronal and sagittal planes;

a converging region is formed at the transition of the spherical region of the medial condyle to the connecting region;

on one side of the connecting area, the highest point of the lateral condyle is 2-6 mm higher than the bottom surface of the patellar sliding groove;

the patellar sliding groove is inclined by 3-8 degrees towards one side of the lateral condyle by taking a sagittal axis as a reference;

the back of the patellar trochlear groove has a first end face, a second end face and a third end face, and the back of the medial condyle spherical region has a fourth end face and a fifth end face; the posterior surface of the lateral condyle spherical region has a sixth end surface and a seventh end surface, wherein,

the second end surface is contracted by 8-16 degrees towards one side of the medial condyle on the basis of a sagittal axis at the lateral edge of the lateral condyle, and the second end surface is contracted by 16-24 degrees towards one side of the lateral condyle on the basis of the sagittal axis at the lateral edge of the medial condyle;

the included angle of the projection of the first end face and the fifth end face/the seventh end face on the sagittal plane is 6 degrees, the included angle of the projection of the second end face and the third end face on the sagittal plane is 45 degrees, and the included angle of the projection of the third end face and the fourth end face/the sixth end face on the sagittal plane is 45 degrees;

the surface of the femoral condyle, which is in contact with the femur, is provided with a porous rough structure, wherein the average porosity of the porous rough structure is 30-70%, the average pore diameter is 100-1000 micrometers, and the average void intercept is 500-1500 micrometers.

2. An artificial knee joint comprising the artificial femoral condyle of claim 1, an artificial tibial plateau and an artificial patella, both of which are silicon nitride ceramics.

3. The artificial knee joint according to claim 2,

the artificial tibial plateau includes a lower surface for contacting a human tibia to form a fixed connection, an upper surface for contacting a femoral condyle to form a tibiofemoral articulating friction pair, and a concave anterior surface for contacting a patella to form a friction pair.

4. The artificial knee of claim 3, wherein the tibial plateau upper surface is provided with medial and lateral condyle receiving areas for receiving medial and lateral condyles of a femoral condyle, respectively, wherein the medial and lateral condyle receiving areas have the same single spherical diameter in the coronal and sagittal planes.

5. The artificial knee joint of claim 4, wherein said medial condyle receiving area is ball and socket shaped for coupling receipt of the spherical medial femoral condyle thereby forming a limited play friction pair; the lateral condyle receiving area is in a concave saddle shape and is used for coupling and receiving the spherical lateral condyle of the femur, so that a limited movable friction pair lower than the inner side is formed, the medial condyle receiving area on the tibial plateau moves in situ along with the motion process from extension to flexion of the knee joint, and the lateral condyle follows the lateral condyle receiving area on the tibial plateau by 10-25 degrees along with the knee flexion motion around the medial condyle.

6. The artificial knee joint according to any one of claims 2 to 5, wherein the lower surface of the tibial plateau has a porous coarse structure having an average porosity of 30% to 70%, an average pore diameter of 100 to 1000 microns, and an average void intercept of 500 to 1500 microns;

the upper surface and the front surface of the tibial plateau are smooth surfaces, and the roughness value Ra of the smooth surfaces is 0.01-1.6 microns.

7. The artificial knee joint according to claim 2,

the artificial patella is an ovoid and comprises a connecting mechanism fixedly connected with the original patella of the human body and an outer peripheral surface which is used for being in contact with the femoral condyle and the tibial plateau to form a joint movable friction pair, the connecting mechanism is arranged on the bottom surface of the ovoid, and the outer peripheral surface corresponds to the spherical surface of the ovoid.

8. The artificial knee of claim 7, wherein the outer peripheral surface of the artificial patella is configured to contact the patellar trochlear groove of the femoral condyle and the anterior surface of the tibial plateau to form an articulating friction pair, and the outer peripheral surface has the same single spherical radius as a correspondingly coupled patellar trochlear groove.

9. The artificial knee joint according to claim 7 or 8, wherein the outer peripheral surface of the artificial patella is a smooth surface having a roughness value Ra of 0.01 to 1.6 μm;

the bottom surface of the ovoid is provided with a porous rough structure, the average porosity of the porous rough structure is 30-70%, the average pore diameter is 100-1000 microns, and the average void intercept is 500-1500 microns;

the edge of the ovoid is set to be a round angle; the connecting mechanism is provided with three connecting parts.