JP6043605B2 - Artificial joint - Google Patents

Description

The present invention relates to artificial joints for prosthetic human joint.

  For joint portions of artificial joints such as artificial elbow joints, artificial knee joints and artificial hip joints for prosthetic human joints, composite molded bodies in which resin and metal are integrally molded are generally used. For example, Patent Document 1 discloses a technique related to an artificial joint in which a resin having a methylene group, specifically, Ultra High Molecular Weight Polyethylene (abbreviated as UHMWPE) is used as a resin.

JP 2010-180410 A

  In the composite molded body of the prior art, the adhesiveness of the resin to the metal is not necessarily high at the boundary between the resin and the metal, and the resin may be partially peeled from the metal. As described above, when the peeled portion is generated in the composite molded body, the composite molded body cannot sufficiently perform the function as the joint portion in the artificial joint. As a result, it becomes necessary to replace the artificial joint embedded in the human body, which is a heavy burden on the patient.

  An object of the present invention is a composite molded body in which a resin and a metal are integrally molded, in which the resin is fixed with high adhesion to the metal, and generation of a peeling portion is suppressed. The present invention provides a method for producing a composite molded body, and an artificial joint including the composite molded body.

  As a result of analyzing the peeled portion in a composite molded body in which a resin and a metal are integrally molded, the present inventors have found that the adhesion of the resin to the metal is closely related to the surface roughness of the metal. The present invention has been completed.

That is, the present invention includes a resin portion molecular weight is 1 million or more ultra-high molecular weight polyethylene resin,
A metal part made of metal having a contact surface in contact with the resin part, the resin part being fixed on the contact surface, and an arithmetic average roughness of the contact surface being not less than 9.3 μm and not more than 20 μm. A composite molded body in which a resin and a metal are integrally molded, and
An artificial joint comprising a contact member that slidably contacts at least a part of the resin part of the composite molded body other than the part fixed to the metal part .

Or the present invention, the complex formation body, and ulna plate is a resin part, an ulnar component comprising the ulnar stem is metal portion, the contact member constitutes an artificial elbow joint is humeral component It is an artificial joint .

According to the present invention, a composite molded body used in artificial joints, and tree fat and metals is configured to include a integrally molded becomes, the resin portion and the metal portion. The resin part is made of an ultra-high molecular weight polyethylene resin having a molecular weight of 1 million or more, and the metal part has a contact surface in contact with the resin part, and the resin part is fixed to the contact surface. In the composite molded body of the present invention having such a configuration, since the metal part has at least the arithmetic average roughness of the contact surface set to 9.3 μm or more and 20 μm or less, the contact area with the resin on the metal contact surface The resin is fixed with high adhesion to the metal. As a result, the resin can be prevented from partially peeling from the metal at the boundary between the resin and the metal.
The artificial joint has a joint part, and the joint part includes the composite molded body and the contact member. The contact member is provided in slidable contact with at least a part of the composite molded body other than the part fixed to the metal part. The artificial joint of the present invention includes a composite molded body in which the resin is prevented from being partially separated from the metal at the boundary between the resin and the metal. In this case, the frequency of replacement due to the occurrence of the peeled portion can be reduced, and the burden on the patient can be reduced.

According to or present invention, in the boundary portion between the ulna plate and ulna stem, since ulna plate is configured to include a ulnar component is suppressed to be partially peeled off from the ulnar stem, artificial elbow joint When embedded and used in the human body, the frequency of replacement can be reduced due to the occurrence of a peeled portion, and the burden on the patient can be reduced.

It is a figure which shows schematically the structure of the composite molded object 1 which concerns on one Embodiment of this invention. It is process drawing which shows the 1st example of the manufacturing method of the composite molded object 1 which concerns on one Embodiment of this invention. It is process drawing which shows the 2nd example of the manufacturing method of the composite molded object 1 which concerns on one Embodiment of this invention. It is a figure showing roughly composition of artificial elbow joint 100 which is an example of an artificial joint concerning one embodiment of the present invention. It is a figure showing roughly composition of artificial knee joint 200 which is an example of an artificial joint concerning one embodiment of the present invention. It is a figure which shows schematically the structure of the artificial hip joint 300 which is an example of the artificial joint which concerns on one Embodiment of this invention.

  FIG. 1 is a diagram schematically showing a configuration of a composite molded body 1 according to an embodiment of the present invention. The composite molded body 1 of the present embodiment is formed by integrally molding a resin and a metal used for an artificial joint for prosthetic a human joint, and includes a resin part 2 and a metal part 3. .

  The resin part 2 is made of an ultra high molecular weight polyethylene (abbreviated UHMWPE) resin having a molecular weight of 1 million or more, preferably 1 million or more and 7 million or less. As UHMWPE, a commercially available product can be used.

Here, the molecular weight of UHMWPE constituting the resin part 2 is determined by the following formula (1) by measuring the viscosity of a decahydronaphthalene (decalin) solution at 135 ° C.
Molecular weight = 5.37 × 10 ⁴ (Intrinsic viscosity) ^1.49 (1)

  The metal part 3 has a contact surface 3A in contact with the resin part 2, and the resin part 2 is fixed to the contact surface 3A. Although the metal part 3 is comprised with a metal material and the metal seed | species is not specifically limited, It is preferable to consist of a metal chosen from titanium, a titanium alloy, and a cobalt chromium alloy.

  In the composite molded body 1 of this embodiment, the metal part 3 has at least an arithmetic average roughness (Ra) of the contact surface 3A of 9.3 μm or more, preferably 9.3 μm or more and 20 μm or less, more preferably 9.3 μm or more. It is set to 10 μm or less. Here, the arithmetic average roughness is measured in accordance with JIS B0601: 2001.

  In the composite molded body 1 of the present embodiment, since the metal part 3 has at least the arithmetic average roughness of the contact surface 3A set to 9.3 μm or more, the metal part 3 and the resin part 2 on the contact surface 3A of the metal part 3 The contact area can be increased, and the resin part 2 is fixed to the metal part 3 with high adhesion. As a result, it is possible to prevent the resin part 2 from being partially separated from the metal part 3 at the boundary part between the resin part 2 and the metal part 3.

  Even when the arithmetic average roughness of the contact surface 3A of the metal part 3 exceeds 20 μm, the adhesiveness of the resin part 2 to the metal part 3 is not changed from the arithmetic average roughness of 20 μm. The upper limit value is set to 20 μm. Moreover, the adhesiveness of the resin part 2 with respect to the metal part 3 can be evaluated visually, and when there is no part which the resin part 2 does not adhere | attach over the whole contact surface 3A of the metal part 3, "high adhesiveness" Can be determined.

  Next, the manufacturing method of the composite molded object 1 of this embodiment is demonstrated. As a manufacturing method of the composite molded body 1, there are two manufacturing methods in which the forming procedure of the resin portion 2 is different.

  FIG. 2 is a process diagram showing a first example of a method for producing a composite molded body 1 according to an embodiment of the present invention. The 1st example of the manufacturing method of the composite molded object 1 contains the surface processing process s1 and the resin part formation process s2.

  In the surface processing step s1, at least a part of the outer surface of the metal member constituting the metal part 3 has an arithmetic average roughness of 9.3 μm or more, preferably 9.3 μm or more and 20 μm or less, more preferably 9.3 μm or more and 10 μm or less. The surface is processed so that Surface processing so that the arithmetic average roughness is in the above range includes mechanical polishing that mechanically rubs the surface of the metal member by physically rubbing the abrasive, chemical polishing as well as mechanical polishing. CMP polishing combined with the above, chemical polishing for polishing the surface of the metal member by a chemical reaction, electrolytic polishing for polishing the surface of the metal member by an electrochemical method, and the like.

  The metal member subjected to the surface processing in the surface processing step s1 is used for the resin portion forming step s2. In the resin part formation step s2, the molecular weight is 1 million or more, preferably 1 million or more by compression-molding the surface of the metal member subjected to the surface processing in the surface processing step s1 under pressure and heating. The resin part 2 made of UHMWPE of 7 million or less is formed. A portion of the metal member constituting the metal portion 3 that has been subjected to surface processing becomes a contact surface 3A to which the resin portion 2 is fixed. The resin part forming step s2 includes a normal temperature compression stage s2-1, a pressure drop temperature rise stage s2-2, a high temperature and high pressure maintenance stage s2-3, and a cooling stage s2-4.

  In the room temperature compression stage s 2-1, a resin powder made of UHMWPE is put into a molding die in a state where a metal member constituting the metal part 3 is arranged at a predetermined position of the molding die, and a pressure of 200 to 250 MPa (eg, 225 MPa) ), And compression (press) at a temperature of 25 ° C. (normal temperature) for 1 to 10 minutes (for example, 7 minutes).

  Next, in the pressure drop temperature rising stage s2-2, the pressure is lowered from the value set in the room temperature compression stage s2-1 to 20 to 35 MPa (for example, 28 MPa), and the temperature is changed from 25 ° C. to 140 to 275 ° C. (for example, , 204 ° C.) and hold for 10 to 40 minutes (for example, 25 minutes).

  Next, in the high-temperature and high-pressure maintenance stage s2-3, the temperature is maintained at the high temperature set in the pressure drop temperature rise stage s2-2, and the pressure is set to 100 from the value set in the pressure drop temperature rise stage s2-2. The pressure is increased to ˜180 MPa (for example, 140 MPa) and held for 1 to 10 minutes (for example, 5 minutes).

  Next, in the cooling stage s2-4, the temperature is maintained for 10 to 50 minutes (for example, 30 minutes) while maintaining the pressure at the value set in the high temperature and high pressure maintenance stage s2-3. Cool gradually from the value set in -3 to 25 ° C (room temperature).

  Thus, the composite molded body 1 including the resin part 2 and the metal part 3 can be manufactured. In the manufacturing method of the composite molded body 1 of the present embodiment, the arithmetic average roughness is 9.3 μm or more, preferably 9.3 μm, in the portion where the resin part 2 is formed on the outer surface of the metal member constituting the metal part 3. Since the surface processing is performed in the surface processing step s1 so as to be 20 μm or less, more preferably 9.3 μm or more and 10 μm or less, the resin portion 2 can be fixed to the metal portion 3 with high adhesion. . As a result, it is possible to obtain a composite molded body 1 in which the resin part 2 is suppressed from being partially peeled from the metal part 3.

  FIG. 3 is a process diagram showing a second example of the method for manufacturing the composite molded body 1 according to the embodiment of the present invention. The 2nd example of the manufacturing method of the composite molded object 1 contains the surface processing process a1 and the resin part formation process a2.

  In the surface processing step a1, at least a part of the outer surface of the metal member constituting the metal part 3 has an arithmetic average roughness of 9.3 μm or more, preferably 9.3 μm or more and 20 μm or less, more preferably 9.3 μm or more and 10 μm or less. The surface is processed so that As a method of surface processing so that the arithmetic average roughness is in the above range, as in the surface processing step s1 in the first example of the manufacturing method of the composite molded body 1 described above, mechanical polishing, CMP polishing, chemical polishing, Examples thereof include electrolytic polishing.

  The metal member subjected to the surface processing in the surface processing step a1 is subjected to the resin part forming step a2. In the resin part forming step a2, on the outer surface of the metal member, the portion subjected to the surface processing in the surface processing step a1 is compression-molded under pressure and heating to have a molecular weight of 1 million or more, preferably 1 million or more. The resin part 2 made of UHMWPE of 7 million or less is formed. A portion of the metal member constituting the metal portion 3 that has been subjected to surface processing becomes a contact surface 3A to which the resin portion 2 is fixed. The resin part forming step a2 includes a preformed product preparation stage a2-1, a pressure heating stage a2-2, a temperature drop pressure increase stage a2-3, and a cooling stage a2-4.

  In the preform production stage a2-1, a resin powder made of UHMWPE is put into the molding die in a state where the metal member constituting the metal part 3 is arranged at a predetermined position of the molding die, and the pressure is 0.5 to 4 MPa. Compress (press) for 10 to 50 minutes (for example, 30 minutes) under pressure and heating (for example, 0.98 MPa) at a temperature of 140 to 180 ° C. (for example, 160 ° C.). Thereafter, while maintaining the pressure, the temperature is gradually cooled to 25 ° C. (ordinary temperature) over 10 to 50 minutes (for example, 30 minutes) to prepare a preform.

  Next, in the pressure heating stage a2-2, the preform formed in the preform preparation stage a2-1 is compression molded under pressure heating. In this pressurization and heating stage a2-2, pressure is 0.1 to 1 MPa (for example, 0.5 MPa) and temperature is 140 to 200 ° C. (for example, 180 ° C.) for 30 to 90 minutes (for example, 55 minutes). ) Compress (press).

  Next, in the temperature drop pressure increase stage a2-3, the temperature is lowered from the value set in the pressure heating stage a2-2 to 120 to 150 ° C., and the pressure is set in the pressure heating stage a2-2. To 0.98-4 MPa (for example, 2 MPa).

  Next, in the cooling stage a2-4, the temperature is raised to the temperature drop pressure over 10 to 50 minutes (for example, 30 minutes) while maintaining the pressure at the value set in the temperature drop pressure rise stage a2-3. Cool gradually from the value set in step a2-3 to 25 ° C. (room temperature).

  Thus, the composite molded body 1 including the resin part 2 and the metal part 3 can be manufactured. In the manufacturing method of the composite molded body 1 of the present embodiment, the arithmetic average roughness is 9.3 μm or more, preferably 9.3 μm, in the portion where the resin part 2 is formed on the outer surface of the metal member constituting the metal part 3. Since the surface processing is performed in the surface processing step a1 so as to be 20 μm or less, more preferably 9.3 μm or more and 10 μm or less, the resin portion 2 can be fixed to the metal portion 3 with high adhesion. . As a result, it is possible to obtain a composite molded body 1 in which the resin part 2 is suppressed from being partially peeled from the metal part 3.

  Next, an example in which the composite molded body 1 of the present embodiment is applied to an artificial joint will be described with reference to FIGS. The composite molded body 1 can be used, for example, for a joint portion of an artificial joint such as an artificial elbow joint, an artificial knee joint, or an artificial hip joint.

  FIG. 4 is a diagram schematically showing a configuration of an artificial elbow joint 100 which is an example of an artificial joint according to an embodiment of the present invention. The artificial elbow joint 100 of the present embodiment is a non-hinge type artificial elbow joint, and includes an ulna component 11 fixed to the proximal part of the ulna and a humerus component 41 fixed to the distal part of the humerus. And are fixed to the respective epiphysis in a separated state.

  The ulna component 11 corresponds to the composite molded body 1. The ulna component 11 includes an ulna plate 21 corresponding to the resin part 2 of the composite molded body 1 and an ulna stem 31 corresponding to the metal part 3 of the composite molded body 1 and fixing the ulna plate 21 to the ulna. Yes.

  The ulna plate 21 has a shape obtained by cutting out a part of the annular member in the radial direction, and the inner surface is a sliding surface 214 that contacts the humeral component 41. The sliding surface 214 of the ulna plate 21 swells from the edge on both sides in the width direction toward the center, and forms a protruding portion 213 extending in the circumferential direction.

  The ulna plate 21 has a tray base material 211 formed from UHMWPE, and the sliding surface 214 of the tray base material 211 may be covered with a polymer film 212. The polymer film 212 is made of, for example, a compound having a phosphorylcholine group. Specifically, the polymer film 212 has a structure in which polymer chains having a phosphorylcholine group are arranged on the surface. Such a structure is similar to the structure of a biological membrane. By covering the sliding surface 214 of the tray base material 211 with the polymer film 212 having a phosphorylcholine group, the sliding characteristics can be improved and the wear resistance can be improved.

  The film thickness of the polymer film 212 is preferably 10 to 200 nm. When the film thickness of the polymer film 212 is less than 10 nm, the wear resistance is insufficient and the durability deteriorates in a short period, which is not preferable. Further, when the film thickness of the polymer film 212 is thicker than 200 nm, the homogeneity of the polymer film 212 tends to be lowered, and a part of the film is thin or no film is generated. This is not preferable because the film 212 is peeled off or the tray base material 211 is worn and wear resistance is lowered.

  Further, as a method of fixing the polymer film 212 to the sliding surface 214 of the tray base material 211, for example, by bonding a polymerizable monomer having a phosphorylcholine group to the sliding surface 214 by graft polymerization using ultraviolet rays. The polymer film 212 can be fixed. In this fixing method, only the sliding surface 214 can be modified without degrading the performance such as the strength of the resin material constituting the tray base material 211, the bonding portion is chemically stable, and a large amount The density of the polymer film 212 can be increased by forming the phosphorylcholine group on the sliding surface 214 of the tray base material 211.

  For the formation of the polymer film 212, a polymerizable monomer having a phosphorylcholine group is used. In particular, a monomer having a phosphorylcholine group at one end and a functional group capable of graft polymerization with the resin material constituting the tray substrate 211 at the other end. Is selected, the polymer film 212 can be grafted to the sliding surface 214 of the tray base material 211.

  Examples of the polymerizable monomer used when forming the polymer film 212 include 2-methacryloyloxyethyl phosphorylcholine, 2-acryloyloxyethyl phosphorylcholine, 4-methacryloyloxybutylphosphorylcholine, 6-methacryloyloxyhexylphosphorylcholine, and ω-methacryloyloxy. Examples include ethylene phosphorylcholine and 4-styryloxybutylphosphorylcholine. In particular, 2-methacryloyloxyethyl phosphorylcholine is preferable.

  The polymer film 212 is formed not only from a homopolymer composed of a single polymerizable monomer having a phosphorylcholine group, but also from a copolymer composed of a monomer having a phosphorylcholine group and, for example, another vinyl compound monomer. You can also Thereby, functions such as improvement of mechanical strength can be added to the polymer film 212.

  The ulnar stem 31 is made of a metal selected from titanium, a titanium alloy, and a cobalt chromium alloy. The ulna stem 31 is for fixing the ulna plate 21 to the ulna, and has a contact surface 31A that comes into contact with the ulna plate 21, and the ulna plate 21 is fixed to the contact surface 31A. In the ulnar stem 31, the arithmetic average roughness of at least the contact surface 31A is set to 9.3 μm or more, preferably 9.3 μm to 20 μm, more preferably 9.3 μm to 10 μm.

  In the ulna component 11 including the ulna plate 21 and the ulna stem 31, the ulna stem 31 has at least the arithmetic average roughness of the contact surface 31 </ b> A set to 9.3 μm or more, so the ulna on the contact surface 31 </ b> A of the ulna stem 31. The contact area with the plate 21 can be increased, and the ulna plate 21 is fixed to the ulna stem 31 with high adhesion. As a result, it is possible to prevent the ulna plate 21 from being partially detached from the ulna stem 31 at the boundary portion between the ulna plate 21 and the ulna stem 31.

  The artificial elbow joint 100 includes the ulna component 11 in which the ulna plate 21 is prevented from being partially detached from the ulna stem 31 at the boundary between the ulna plate 21 and the ulna stem 31. When embedded and used in the body, the frequency of replacement can be reduced due to the occurrence of a peeled portion, and the burden on the patient can be reduced.

  The humerus component 41 of the artificial elbow joint 100 functions as a contact member that slidably contacts at least a part of the ulna plate 21 of the ulna component 11 other than the part fixed to the ulna stem 31. The humerus component 41 is formed from metal or ceramics, and has a substantially cylindrical shape partially cut away. The outer surface of the humeral component 41 is slightly constricted in the middle to form a pulley 41A. By fitting the pulley 41 </ b> A of the humeral component 41 and the protruding portion 213 of the ulna plate 21, the artificial elbow joint 100 that can bend and stretch forward and backward is formed.

  FIG. 5 is a diagram schematically showing a configuration of an artificial knee joint 200 that is an example of an artificial joint according to an embodiment of the present invention. The artificial knee joint 200 of the present embodiment is a non-hinge type artificial knee joint, and includes a tibial component 12 fixed to the proximal portion of the tibia and a femoral component 42 fixed to the distal portion of the femur. And are fixed to the respective epiphysis in a separated state.

  The tibial component 12 corresponds to the composite molded body 1. The tibial component 12 includes a tibial plate 22 corresponding to the resin portion 2 of the composite molded body 1 and a tibial tray 32 corresponding to the metal portion 3 of the composite molded body 1 and fixing the tibial plate 22 to the tibia. Yes.

  On the upper surface of the tibial plate 22, a curved dent extending from the front direction (the direction of the kneecap) A to the rear direction (the direction of the back of the knee) P is formed, and this dent is a femoral component 42 described later. The sliding surface 223 is in contact with the two curved projections 42A.

  The tibial plate 22 has a tray base material 221 formed from UHMWPE, and the sliding surface 223 of the tray base material 221 may be covered with the polymer film 222. Similar to the polymer film 212 formed on the ulna plate 21, the polymer film 222 is formed of a phosphorylcholine group-containing polymer chain grafted to the sliding surface 223.

  The tibial tray 32 is made of a metal selected from titanium, a titanium alloy, and a cobalt chromium alloy. The tibial tray 32 is for fixing the tibial plate 22 to the tibia and has a contact surface 32A that comes into contact with the tibial plate 22, and the tibial plate 22 is fixed to the contact surface 32A. In the tibial tray 32, the arithmetic average roughness of at least the contact surface 32A is set to 9.3 μm or more, preferably 9.3 μm to 20 μm, more preferably 9.3 μm to 10 μm.

  In the tibial component 12 including the tibial plate 22 and the tibial tray 32, the tibial tray 32 has an arithmetic average roughness of at least the contact surface 32A set to 9.3 μm or more. The contact area with the plate 22 can be increased, and the tibial plate 22 is fixed to the tibial tray 32 with high adhesion. As a result, it is possible to prevent the tibial plate 22 from being partially detached from the tibial tray 32 at the boundary portion between the tibial plate 22 and the tibial tray 32.

  The artificial knee joint 200 includes the tibial component 12 in which the tibial plate 22 is prevented from being partially detached from the tibial tray 32 at the boundary portion between the tibial plate 22 and the tibial tray 32. When embedded and used in the body, the frequency of replacement can be reduced due to the occurrence of a peeled portion, and the burden on the patient can be reduced.

  The femoral component 42 of the knee prosthesis 200 functions as a contact member that slidably contacts at least a portion of the tibial plate 22 of the tibial component 12 other than the portion secured to the tibial tray 32. The femoral component 42 is formed of metal or ceramics, and has two curved protrusions 42A (corresponding to the medial condyle and the lateral condyle) extending in an arc from the front direction A to the back direction P on the lower surface side thereof. ).

  The artificial knee joint 200 can bend and stretch in the front-rear direction by sliding the curved protrusion 42A of the femoral component 42 and the sliding surface 223 of the tibial plate 22.

  FIG. 6 is a diagram schematically showing the configuration of an artificial hip joint 300 that is an example of an artificial joint according to an embodiment of the present invention. The hip prosthesis 300 according to the present embodiment is a bipolar hip prosthesis, and includes an outer head 13 fixed to the acetabular acetabulum and a femoral stem 43 fixed to the proximal end of the femur. Yes.

  The outer head 13 corresponds to the composite molded body 1. This outer head 13 receives a bone head 43A of a femoral stem 43 described later, a liner 23 corresponding to the resin portion 2 of the composite molded body 1, and an outer shell corresponding to the metal portion 3 of the composite molded body 1. 33.

  The liner 23 has a liner base material 231 formed from UHMWPE provided along the inner peripheral surface of the outer shell 33 which is a hemispherical hollow member, and the liner base material 231 has a sliding surface 233. The polymer film 232 may be covered. Similar to the polymer film 212 formed on the ulna plate 21, the polymer film 232 is formed of a phosphorylcholine group-containing polymer chain grafted to the sliding surface 233.

  The outer shell 33 is a hemispherical hollow member and is made of a metal selected from titanium, a titanium alloy, and a cobalt chromium alloy. The outer shell 33 is for fixing the liner 23 to the head 43A of the femoral stem 43, and has a contact surface 33A that comes into contact with the liner 23, and the liner 23 is fixed to the contact surface 33A. In the outer shell 33, at least the arithmetic mean roughness of the contact surface 33A is set to 9.3 μm or more, preferably 9.3 μm to 20 μm, more preferably 9.3 μm to 10 μm.

  In the outer head 13 composed of the liner 23 and the outer shell 33, the outer shell 33 has at least the arithmetic average roughness of the contact surface 33A set to 9.3 μm or more. The area of contact with the outer shell 33 can be increased, and the liner 23 is fixed to the outer shell 33 with high adhesion. As a result, it is possible to prevent the liner 23 from partially peeling from the outer shell 33 at the boundary portion between the liner 23 and the outer shell 33.

  Since the artificial hip joint 300 includes the outer head 13 in which the liner 23 is prevented from being partially peeled from the outer shell 33 at the boundary portion between the liner 23 and the outer shell 33, the artificial hip joint 300 is embedded in the human body. When used, the frequency of replacement due to the occurrence of the peeled portion can be reduced, and the burden on the patient can be reduced.

  The femoral stem 43 of the artificial hip joint 300 functions as a contact member that slidably contacts at least a portion of the liner 23 of the outer head 13 other than the portion fixed to the outer shell 33. The femoral stem 43 is formed of metal or ceramics and includes a ball-shaped bone head 43A and a stem body 43B. The bone head 43A is fixed to the proximal portion of the stem body 43B.

  The artificial hip joint 300 functions as a hip joint by fitting and sliding the head 43A of the femoral stem 43 on the sliding surface 233 of the liner base material 231.

DESCRIPTION OF SYMBOLS 1 Composite molded body 2 Resin part 3 Metal part 3A Contact surface 11 Ulna component 12 Tibial component 13 Outer head 21 Ulna plate 22 Tibial plate 23 Liner 31 Ulna stem 32 Tibial tray 33 Outer shell 41 Humeral component 42 Femoral component 43 Femur Stem 100 Artificial elbow joint 200 Artificial knee joint 300 Artificial hip joint

Claims (2)

A resin portion which molecular weight is 1 million or more ultra-high molecular weight polyethylene resin,
A metal part made of metal having a contact surface in contact with the resin part, the resin part being fixed on the contact surface, and an arithmetic average roughness of the contact surface being not less than 9.3 μm and not more than 20 μm. A composite molded body in which a resin and a metal are integrally molded, and
An artificial joint comprising: a contact member that slidably contacts at least a part of the resin part of the composite molded body other than a part fixed to the metal part . The artificial composite body according to claim 1, wherein the composite body is an ulna component including an ulna plate as a resin part and an ulna stem as a metal part, and the contact member constitutes an artificial elbow joint which is a humerus component. joint.

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