CN114831780A - Cobalt alloy bone trabecula femur condyle prosthesis containing nitride layer and preparation method thereof - Google Patents

Abstract

The invention discloses a trabecular femoral condyle prosthesis containing nitrided-layer cobalt alloy and a preparation method. The preparation method comprises the following steps: using cobalt alloy powder as a raw material, and integrally forming by 3D printing to obtain a cobalt-containing alloy trabecular femoral condyle prosthesis containing a nitrided layer. The intermediate product of the trabecular femoral condyle is prepared by hot isostatic pressing and surface nitridation to prepare the cobalt alloy trabecular femoral condyle prosthesis with nitride layer; some positions of the cobalt alloy trabecular femoral condyle prosthesis containing nitride layer are provided with By partitioning the trabecular bone, the invention realizes that the microstrain in most areas of the femoral condyle bone tissue is between the minimum effective strain threshold and the superphysiological strain threshold, which is beneficial to bone ingrowth and improves long-term stability. The invention has good biocompatibility, induces cell proliferation, prevents the cytotoxic reaction caused by the long-term use of the metal trabecular porous cobalt alloy by the precipitation of matrix ions, and the joint prosthesis of the same material can satisfy the osteoinductivity and wear resistance at the same time. It solves the problem of conventionally using two components or using coating technology in the substrate to complete two interface functions, and the problem of coating peeling after long-term use.

Description

Cobalt alloy trabecular femoral condyle prosthesis containing nitride layer and preparation method thereof

technical field

The invention relates to the technical field of medical implant materials, in particular to a trabecular femoral condyle prosthesis containing a nitrided-layer cobalt alloy and a preparation method thereof.

Background technique

Total knee arthroplasty is an effective clinical treatment for end-stage knee joint diseases. It replaces the damaged knee joint tissue with artificially designed joint prostheses, thereby relieving the patient's pain, restoring their knee joint function, and improving their life. quality. Corresponding to the anatomical structure of the human body, the components of the knee joint prosthesis include the femoral condyle, the tibial plateau and the platform pad. With the rapid development of medical device technology and the continuous improvement of people's requirements for the safety and effectiveness of prosthetic products, knee joint prosthesis design and manufacturing technology will require continuous optimization and improvement.

At present, the clinical application of knee joint prosthesis includes two categories: cement type and biological type (non-cement fixation). Among them, the cemented prosthesis relies on the curing and filling of the bone cement to mechanically fix the joint prosthesis and the bone tissue. However, many years of clinical application have found that bone cement fixation can bring many safety and effectiveness problems: the polymerization of bone cement monomer releases heat, causing damage to surrounding tissues; if bone cement particles enter the blood or cause high pressure in the medullary cavity during filling, it will lead to Pulmonary embolism and fat embolism.

Biological knee joint prostheses can effectively eliminate the safety and efficacy risks brought by bone cement, and usually use the superficial porous structure to promote bone ingrowth and obtain long-term stability. However, its surface porous structure is usually obtained by surface treatment processes such as sandblasting, coating, and sintering. Moreover, according to Wolff's law: after stress causes bone to deform (also known as micro-strain), the original signal can be activated to regulate bone synthesis and catabolism, and the strain range can only promote bone growth between the minimum effective strain threshold and the supraphysiological strain threshold. grow. Therefore, it is of great significance to design a knee femoral condyle prosthesis to achieve the microstrain in most areas of the bone tissue between the minimum effective strain threshold and the supraphysiological strain threshold, which is beneficial to bone ingrowth.

Cobalt alloys are commonly used clinically implanted metal prosthesis materials with high wear resistance and fatigue strength, but their manufacturing processes are usually casting and forging. 3D printing technology can realize the concept of performance-oriented product design, solve the difficulty of integral molding of complex parts, and reduce the waste of raw materials and energy caused by machining. The 3D printed metal trabeculae and solid structure can be formed at one time, which can avoid the disadvantage that the coating is easy to fall off. However, the micro-nano structure of metal trabeculae can increase the surface pressure of cobalt alloys and thus increase ion precipitation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a trabecular femoral condyle prosthesis containing a nitrided-layer cobalt alloy.

The second object of the present invention is to provide a preparation method of a cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer.

The technical scheme of the present invention is summarized as follows:

The preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing nitride layer comprises the following steps:

1) Using cobalt alloy powder as raw material, the first intermediate product is obtained by integral molding through 3D printing, and the first intermediate product is put into a hot isostatic pressing furnace, and is heated to 1165 ℃ - 1170 ℃ under the protection of inert gas, and the temperature is 130MPa-140MPa, placed at a constant temperature for 1h-3h, lowered to normal pressure, cooled to room temperature with the furnace, taken out to obtain the second intermediate product;

2) use deionized water and absolute ethanol successively to carry out ultrasonic cleaning to the second intermediate product, remove surface impurities, and dry; put into the vacuum chamber of the plasma immersion implanter, and vacuumize; negative high pressure, the injection volume ratio is (2- 1): the mixture of nitrogen and argon of 1, the injection time is 5min-45min, after the injection is completed, take out to obtain the third intermediate product;

3) carrying out machining trimming, polishing, cleaning and drying on the third intermediate product to obtain a cobalt-containing nitride-layer trabecular femoral condyle prosthesis;

The first intermediate product, the second intermediate product, and the third intermediate product have the same structure as the nitrided-layer cobalt alloy bone trabecular femoral condyle prosthesis.

Preferably, the cobalt alloy powder includes 60%-67% Co, 27%-30% Cr, 5%-7% Mo, and the balance is impurity elements by mass percentage; the particle size of the cobalt alloy powder is 45 μm -106μm.

Step 2) is preferably as follows: ultrasonically clean the second intermediate product with deionized water and absolute ethanol successively, remove surface impurities, and dry; put it into the vacuum chamber of the plasma immersion implanter, and evacuate to 5*10 ^-4 Pa The negative high voltage is 10kV-15kV, the injection volume ratio is (2-1): 1 mixture of nitrogen and argon, the injection time is 5min-45min, and the injection is completed and taken out to obtain the third intermediate product.

Preferably, the cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer includes a medial condyle 11 and a lateral condyle 12 arranged left and right, the medial condyle front end 1101 of the medial condyle 11 is integrated with the lateral condyle front end 1102 of the lateral condyle 12, The rear end of the condyle 11 and the rear end of the outer condyle 12 are connected by a limit stop 15; the outer side wall of the inner condyle 11 and the outer side wall of the outer condyle 12 are both provided with a holding groove 16, and the inner condyle 11 has an inner side The condyle fixation surface 110, the lateral condyle has a lateral condyle fixation surface 120; the medial condyle fixation surface 110 includes a first fixation surface 111, a second fixation surface 112, a third fixation surface 113, and a fourth fixation surface 114 that are connected in sequence. and the fifth fixation surface 115, the lateral condyle fixation surface 120 includes the sixth fixation surface 121, the seventh fixation surface 122, the eighth fixation surface 123, the ninth fixation surface 124 and the tenth fixation surface 125 which are connected in sequence; the A mounting hole 17 is provided in the middle of the third fixing surface 113 and the eighth fixing surface 123 . The first fixing surface 111 and the second fixing surface 112 intersect to form a first intersection line 181 ; the second fixing surface 112 and the third fixing surface 113 The intersection forms the second intersection line 182; the third fixed surface 113 and the fourth fixed surface 114 intersect to form the third intersection line 183; the fourth fixed surface 114 and the fifth fixed surface 115 form the fourth intersection line 184; the sixth fixed surface 121 The intersection with the seventh fixed surface 122 is collinear with the first intersection 181; the intersection of the seventh fixed surface 122 and the eighth fixed surface 123 is collinear with the second intersection 182; the eighth fixed surface 123 and the ninth fixed The intersection line of the surface 124 is collinear with the third intersection line 183; the intersection line of the ninth fixed surface 124 and the tenth fixed surface 125 is collinear with the fourth intersection line 184; the first intersection line 181 and the second intersection line 182 , the third intersection 183 and the fourth intersection 184 are parallel to each other;

The angle between the first fixing surface 111 and the second fixing surface 112 and the angle between the sixth fixing surface 121 and the seventh fixing surface 122 are equal to 130°-140°; the second fixing surface 112 and the third fixing surface The angle between the 113 and the seventh fixing surface 122 and the eighth fixing surface 123 is equal to 130°-140°; the angle between the third fixing surface 113 and the fourth fixing surface 114 is the same as that between the eighth fixing surface 123 and the first fixing surface The angle between the nine fixing surfaces 124 is equal to 130°-140°; the angle between the fourth fixing surface 114 and the fifth fixing surface 115 and the angle between the ninth fixing surface 124 and the tenth fixing surface 125 are equal to 130° -140°;

The first fixing surface 111 , the fifth fixing surface 115 , the sixth fixing surface 121 and the tenth fixing surface 125 are provided with the first type of bone trabeculae 191 ;

The second fixing surface 112, the fourth fixing surface 114, the seventh fixing surface 122 and the ninth fixing surface 124 are provided with a second type of bone trabeculae 192;

The third fixing surface 113 and the eighth fixing surface 123 are provided with a third type of trabecular bone 193;

The pore size and porosity of the first type of bone trabeculae 191 are smaller than those of the second type of bone trabeculae 192 and the third type of bone trabecula 193 in turn.

The first type of trabecular bone 191 has a diameter of 0.74mm-0.85mm, a porosity of 70.0%-74.7%, and a through-porosity of 100%;

The second type of trabecular bone 192 has a diameter of 0.86mm-0.99mm, a porosity of 74.8%-77.5%, and a through-porosity of 100%;

The third type of trabecular bone 193 has a pore size of 1.00mm-1.10mm, a porosity of 77.6%-85%, and a through-porosity of 100%.

The thicknesses of the first type of bone trabeculae 191, the second type of bone trabeculae 192 and the third type of bone trabeculae 193 are equal to 0.5mm-3mm.

A rectangular first solid structure 21 is arranged at the joint of the second fixing surface and the seventh fixing surface; a semicircular second solid structure 20 is arranged at the joint of the first fixing surface and the sixth fixing surface. The thickness of the solid structure 21 and the second solid structure 20 is equal to the thickness of the trabecular bone, which is 0.5mm-3mm.

Preferably, a side wall 22 is provided on the edge of the fixing surface formed by the medial condyle fixation surface 110 , the lateral condyle fixation surface 120 and the limiting block 15 .

According to another aspect of the present invention, there is also provided a cobalt alloy trabecular femoral condyle prosthesis prepared according to the above method.

The advantage of the present invention is that, according to the cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer of the present invention, the microstrain in most areas of the femoral condyle bone tissue is between the minimum effective strain threshold and the supraphysiological strain threshold, which is beneficial to bone grow into, improve long-term stability.

Secondly, the present invention adopts 3D printing for integral molding, which solves the problem that traditional machining cannot prepare complex structures, and the bone trabecular and the solid have high bonding strength, which is not easy to fall off, and prolongs the life of the prosthesis.

Moreover, the trabecular bone (ie, the trabecular bone layer) of the cobalt alloy trabecular femoral condyle prosthesis of the present invention has good biocompatibility, induces cell proliferation, and prevents cytotoxicity caused by the precipitation of matrix ions for a long time. Reaction; The friction interface utilizes the good wear properties of cobalt alloys and still maintains a low wear rate of the joint prosthesis. In this way, the joint prosthesis of the same material can satisfy both the osteoinductive and wear resistance properties, and avoid the problem of conventionally using two components or using coating technology in the matrix to complete the two interface functions, which will cause the coating to fall off after long-term use.

Description of drawings

FIG. 1 is an axonometric view of the trabecular femoral condyle prosthesis of the present invention, which is viewed from the lateral condyle.

FIG. 2 is an axonometric view of the trabecular femoral condyle prosthesis (including the first solid structure and the second solid structure) of the present invention, which is viewed from the medial condyle.

3 is an axonometric view of the trabecular femoral condyle prosthesis of the present invention, which is viewed from the front of the femoral condyle.

FIG. 4 is a finite element analysis strain cloud diagram of the cobalt-alloy trabecular femoral condyle prosthesis with a nitride layer in Example 1 observed from the front of the femoral condyle.

5 is a finite element analysis strain cloud diagram of the cobalt-alloy trabecular femoral condyle prosthesis containing a nitride layer observed from the rear of the femoral condyle in Example 1. FIG.

Figure 6 is the scanning electron microscope image and relative element content of the cobalt alloy trabecular bone test piece of control group 1.

FIG. 7 is the scanning electron microscope image and relative element content of the cobalt alloy trabecular bone test piece of the nitride layer in Example 1. FIG.

Figure 8 shows the results of the MTT proliferation test of the trabecular bone test piece, which specifically compares the co-culture of the cobalt alloy trabecular bone test piece containing the nitride layer of Example 1 and the cobalt alloy trabecular bone test piece of the control group 1 and osteoblasts. MTT value (OD).

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Example 1

The preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing nitride layer comprises the following steps:

1) Using cobalt alloy powder as a raw material, the first intermediate product is obtained by integral molding through 3D printing, and the first intermediate product is put into a hot isostatic pressing furnace, and under the protection of inert gas, the temperature is raised to 1168 ° C, at 135 MPa, constant temperature placed for 2h, reduced to normal pressure, cooled to room temperature with the furnace, taken out to obtain the second intermediate product;

2) Perform ultrasonic cleaning on the second intermediate product with deionized water and absolute ethanol in turn to remove surface impurities and dry; put it into the vacuum chamber of a plasma immersion implanter (Chengdu Tongchuang, D700) to 5*10 ^-4 Pa; the negative high voltage is 13kV, the mixture of nitrogen and argon with a volume ratio of 1.5:1 is injected, the injection time is 25min, and the injection is completed and taken out to obtain the third intermediate product;

3) carrying out machining trimming, polishing, cleaning and drying on the third intermediate product to obtain a cobalt-containing nitride-layer trabecular femoral condyle prosthesis;

The first intermediate product, the second intermediate product, and the third intermediate product have the same structure as the nitrided-layer cobalt alloy bone trabecular femoral condyle prosthesis.

The cobalt alloy powder includes 65% of Co, 28% of Cr, 6% of Mo by mass percentage, and the balance is impurity elements; the particle size of the cobalt alloy powder is 75 μm.

The cobalt alloy trabecular femoral condyle prosthesis containing nitride layer includes medial condyle 11 and lateral condyle 12 arranged on the left and right, the medial condyle front end 1101 of the medial condyle 11 and the lateral condyle front end 1102 of the lateral condyle 12 are integrated, and the medial condyle 11 is integrated. The rear end portion and the rear end portion of the lateral condyle 12 are connected by a limit block 15; the lateral wall of the medial condyle 11 and the lateral wall of the lateral condyle 12 are both provided with a holding groove 16, and the medial condyle 11 has a medial condyle fixing surface 110, the outer condyle has an outer condyle fixing surface 120; the inner condyle fixing surface 110 includes the first fixing surface 111, the second fixing surface 112, the third fixing surface 113, the fourth fixing surface 114 and the fifth fixing surface 111 that are connected in turn. The fixation surface 115, the lateral condyle fixation surface 120 includes a sixth fixation surface 121, a seventh fixation surface 122, an eighth fixation surface 123, a ninth fixation surface 124 and a tenth fixation surface 125 which are connected in sequence; the third fixation surface A mounting hole 17 is provided in the middle of the surface 113 and the eighth fixing surface 123. The first fixing surface 111 and the second fixing surface 112 intersect to form a first intersection line 181; The second intersection 182; the third fixed surface 113 and the fourth fixed surface 114 intersect to form the third intersection 183; the fourth fixed surface 114 and the fifth fixed surface 115 form the fourth intersection 184; the sixth fixed surface 121 and the seventh The intersection line of the fixing surface 122 is collinear with the first intersection line 181; the intersection line of the seventh fixing surface 122 and the eighth fixing surface 123 is collinear with the second intersection line 182; The intersection line is collinear with the third intersection line 183; the intersection line of the ninth fixed surface 124 and the tenth fixed surface 125 is collinear with the fourth intersection line 184; the first intersection line 181, the second intersection line 182, the third intersection line 184 The intersection line 183 and the fourth intersection line 184 are parallel to each other;

The angle between the first fixing surface 111 and the second fixing surface 112 is equal to the angle between the sixth fixing surface 121 and the seventh fixing surface 122, which is 135°; the angle between the second fixing surface 112 and the third fixing surface 113 is equal to 135°; The angle is equal to the angle between the seventh fixing surface 122 and the eighth fixing surface 123 , which is 135°; The angles are equal, which is 135°; the angle between the fourth fixing surface 114 and the fifth fixing surface 115 is equal to the angle between the ninth fixing surface 124 and the tenth fixing surface 125, which is 135°;

The first fixing surface 111 , the fifth fixing surface 115 , the sixth fixing surface 121 and the tenth fixing surface 125 are provided with the first type of bone trabeculae 191 ;

The second fixing surface 112, the fourth fixing surface 114, the seventh fixing surface 122 and the ninth fixing surface 124 are provided with a second type of bone trabeculae 192;

The third fixing surface 113 and the eighth fixing surface 123 are provided with a third type of trabecular bone 193;

The pore size and porosity of the first type of bone trabeculae 191 are smaller than those of the second type of bone trabeculae 192 and the third type of bone trabecula 193 in turn.

The first type of trabecular bone 191 has a diameter of 0.80mm, a porosity of 72%, and a through-porosity of 100%; the second type of bone trabecular 192 has a diameter of 0.92mm, a porosity of 76%, and a through-porosity of 100%; The third type of bone trabecular 193 has a diameter of 1.05 mm, a porosity of 80%, and a through-porosity of 100%.

The first type of bone trabeculae 191, the second type of bone trabecular 192 and the third type of bone trabecular 193 have the same thickness, which is 1.7 mm.

A rectangular first solid structure 21 is arranged at the joint of the second fixing surface and the seventh fixing surface; a semicircular second solid structure 20 is arranged at the joint of the first fixing surface and the sixth fixing surface. The thickness of the solid structure 21 and the second solid structure 20 is equal to the thickness of the trabecular bone, which is 1.7 mm.

A side wall 22 is provided on the edge of the fixing surface formed by the medial condyle fixation surface 110 , the lateral condyle fixation surface 120 and the limit stopper 15 .

Example 2

The preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing nitride layer comprises the following steps:

1) Using cobalt alloy powder as a raw material, the first intermediate product is obtained by integral molding through 3D printing. The first intermediate product is put into a hot isostatic pressing furnace, and is heated to 1165 ° C under the protection of an inert gas, and is kept at a constant temperature of 130 MPa. placed for 3h, reduced to normal pressure, cooled to room temperature with the furnace, taken out to obtain the second intermediate product;

2) Perform ultrasonic cleaning on the second intermediate product with deionized water and absolute ethanol in turn to remove surface impurities and dry; put it into the vacuum chamber of a plasma immersion implanter (Chengdu Tongchuang, D700) to 5*10 ^-4 Pa; the negative high voltage is 10kV, the mixture of nitrogen and argon with a volume ratio of 2:1 is injected, the injection time is 45min, and the injection is completed and taken out to obtain the third intermediate product;

3) carrying out machining trimming, polishing, cleaning and drying on the third intermediate product to obtain a cobalt-containing nitride-layer trabecular femoral condyle prosthesis;

The first intermediate product, the second intermediate product, and the third intermediate product have the same structure as the nitrided-layer cobalt alloy bone trabecular femoral condyle prosthesis.

The cobalt alloy powder includes 60% of Co, 30% of Cr, 7% of Mo by mass percentage, and the balance is impurity elements; the particle size of the cobalt alloy powder is 45 μm.

The cobalt alloy trabecular femoral condyle prosthesis containing nitride layer includes medial condyle 11 and lateral condyle 12 arranged on the left and right, the medial condyle front end 1101 of the medial condyle 11 and the lateral condyle front end 1102 of the lateral condyle 12 are integrated, and the medial condyle 11 is integrated. The rear end portion and the rear end portion of the lateral condyle 12 are connected by a limit block 15; the lateral wall of the medial condyle 11 and the lateral wall of the lateral condyle 12 are both provided with a holding groove 16, and the medial condyle 11 has a medial condyle fixing surface 110, the outer condyle has an outer condyle fixing surface 120; the inner condyle fixing surface 110 includes the first fixing surface 111, the second fixing surface 112, the third fixing surface 113, the fourth fixing surface 114 and the fifth fixing surface 111 that are connected in turn. The fixation surface 115, the lateral condyle fixation surface 120 includes a sixth fixation surface 121, a seventh fixation surface 122, an eighth fixation surface 123, a ninth fixation surface 124 and a tenth fixation surface 125 which are connected in sequence; the third fixation surface A mounting hole 17 is provided in the middle of the surface 113 and the eighth fixing surface 123. The first fixing surface 111 and the second fixing surface 112 intersect to form a first intersection line 181; The second intersection 182; the third fixed surface 113 and the fourth fixed surface 114 intersect to form the third intersection 183; the fourth fixed surface 114 and the fifth fixed surface 115 form the fourth intersection 184; the sixth fixed surface 121 and the seventh The intersection line of the fixing surface 122 is collinear with the first intersection line 181; the intersection line of the seventh fixing surface 122 and the eighth fixing surface 123 is collinear with the second intersection line 182; The intersection line is collinear with the third intersection line 183; the intersection line of the ninth fixed surface 124 and the tenth fixed surface 125 is collinear with the fourth intersection line 184; the first intersection line 181, the second intersection line 182, the third intersection line 184 The intersection line 183 and the fourth intersection line 184 are parallel to each other;

The angle between the first fixing surface 111 and the second fixing surface 112 is equal to the angle between the sixth fixing surface 121 and the seventh fixing surface 122 , which is 130°; the angle between the second fixing surface 112 and the third fixing surface 113 The angle is equal to the angle between the seventh fixing surface 122 and the eighth fixing surface 123 , which is 130°; the angle between the third fixing surface 113 and the fourth fixing surface 114 and the angle between the eighth fixing surface 123 and the ninth fixing surface 124 The angles are equal, which is 130°; the angle between the fourth fixing surface 114 and the fifth fixing surface 115 and the angle between the ninth fixing surface 124 and the tenth fixing surface 125 are equal, which is 130°;

The first fixing surface 111 , the fifth fixing surface 115 , the sixth fixing surface 121 and the tenth fixing surface 125 are provided with the first type of bone trabeculae 191 ;

The second fixing surface 112, the fourth fixing surface 114, the seventh fixing surface 122 and the ninth fixing surface 124 are provided with a second type of bone trabeculae 192;

The third fixing surface 113 and the eighth fixing surface 123 are provided with a third type of trabecular bone 193;

The pore size and porosity of the first type of bone trabeculae 191 are smaller than those of the second type of bone trabeculae 192 and the third type of bone trabecula 193 in turn.

The first type of trabecular bone 191 has a diameter of 0.74 mm, a porosity of 70.0%, and a through-porosity of 100%; the second type of trabecular bone 192 has a diameter of 0.86 mm, a porosity of 74.8%, and a through-porosity of 100%; The third type of trabecular bone 193 has a diameter of 1.00 mm, a porosity of 77.6%, and a through-porosity of 100%.

The thickness of the first type of bone trabecular 191, the second type of bone trabecular 192 and the third type of bone trabecular 193 is equal to 0.5 mm.

A rectangular first solid structure 21 is arranged at the joint of the second fixing surface and the seventh fixing surface; a semicircular second solid structure 20 is arranged at the joint of the first fixing surface and the sixth fixing surface. The thickness of the solid structure 21 and the second solid structure 20 is equal to the thickness of the trabecular bone, which is 0.5 mm.

A side wall 22 is provided on the edge of the fixing surface formed by the medial condyle fixation surface 110 , the lateral condyle fixation surface 120 and the limit stopper 15 .

Example 3

The preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing nitride layer comprises the following steps:

1) Using cobalt alloy powder as a raw material, the first intermediate product is obtained by integral molding through 3D printing, and the first intermediate product is put into a hot isostatic pressing furnace, and is heated to 1170 ° C under the protection of inert gas, and is kept at a constant temperature of 140 MPa. Placed for 1 hour, reduced to normal pressure, cooled to room temperature with the furnace, taken out to obtain the second intermediate product;

2) Perform ultrasonic cleaning on the second intermediate product with deionized water and absolute ethanol in turn to remove surface impurities and dry; put it into the vacuum chamber of a plasma immersion implanter (Chengdu Tongchuang, D700) to 5*10 ^-4 Pa; the negative high voltage is 15kV, the mixture of nitrogen and argon with a volume ratio of 1:1 is injected, the injection time is 5min, and the injection is completed and taken out to obtain the third intermediate product;

3) carrying out machining trimming, polishing, cleaning and drying on the third intermediate product to obtain a cobalt-containing nitride-layer trabecular femoral condyle prosthesis;

The first intermediate product, the second intermediate product, and the third intermediate product have the same structure as the nitrided-layer cobalt alloy bone trabecular femoral condyle prosthesis.

The cobalt alloy powder includes 67% of Co, 27% of Cr, 5% of Mo by mass percentage, and the balance is impurity elements; the particle size of the cobalt alloy powder is 106 μm.

The cobalt alloy trabecular femoral condyle prosthesis containing nitride layer includes medial condyle 11 and lateral condyle 12 arranged on the left and right, the medial condyle front end 1101 of the medial condyle 11 and the lateral condyle front end 1102 of the lateral condyle 12 are integrated, and the medial condyle 11 is integrated. The rear end portion and the rear end portion of the lateral condyle 12 are connected by a limit block 15; the lateral wall of the medial condyle 11 and the lateral wall of the lateral condyle 12 are both provided with a holding groove 16, and the medial condyle 11 has a medial condyle fixing surface 110, the outer condyle has an outer condyle fixing surface 120; the inner condyle fixing surface 110 includes the first fixing surface 111, the second fixing surface 112, the third fixing surface 113, the fourth fixing surface 114 and the fifth fixing surface 111 that are connected in turn. The fixation surface 115, the lateral condyle fixation surface 120 includes a sixth fixation surface 121, a seventh fixation surface 122, an eighth fixation surface 123, a ninth fixation surface 124 and a tenth fixation surface 125 which are connected in sequence; the third fixation surface A mounting hole 17 is provided in the middle of the surface 113 and the eighth fixing surface 123. The first fixing surface 111 and the second fixing surface 112 intersect to form a first intersection line 181; The second intersection 182; the third fixed surface 113 and the fourth fixed surface 114 intersect to form the third intersection 183; the fourth fixed surface 114 and the fifth fixed surface 115 form the fourth intersection 184; the sixth fixed surface 121 and the seventh The intersection line of the fixing surface 122 is collinear with the first intersection line 181; the intersection line of the seventh fixing surface 122 and the eighth fixing surface 123 is collinear with the second intersection line 182; The intersection line is collinear with the third intersection line 183; the intersection line of the ninth fixed surface 124 and the tenth fixed surface 125 is collinear with the fourth intersection line 184; the first intersection line 181, the second intersection line 182, the third intersection line 184 The intersection line 183 and the fourth intersection line 184 are parallel to each other;

The angle between the first fixing surface 111 and the second fixing surface 112 is equal to the angle between the sixth fixing surface 121 and the seventh fixing surface 122 , which is 140°; the angle between the second fixing surface 112 and the third fixing surface 113 The angle is equal to the angle between the seventh fixing surface 122 and the eighth fixing surface 123 , which is 140°; The angles are equal, which is 140°; the angle between the fourth fixing surface 114 and the fifth fixing surface 115 and the angle between the ninth fixing surface 124 and the tenth fixing surface 125 are equal, which is 140°;

The first fixing surface 111 , the fifth fixing surface 115 , the sixth fixing surface 121 and the tenth fixing surface 125 are provided with the first type of bone trabeculae 191 ;

The second fixing surface 112, the fourth fixing surface 114, the seventh fixing surface 122 and the ninth fixing surface 124 are provided with a second type of bone trabeculae 192;

The third fixing surface 113 and the eighth fixing surface 123 are provided with a third type of trabecular bone 193;

The pore size and porosity of the first type of bone trabeculae 191 are smaller than those of the second type of bone trabeculae 192 and the third type of bone trabecula 193 in turn.

The first type of trabecular bone 191 has a diameter of 0.85mm, a porosity of 74.7%, and a through-porosity of 100%; the second type of bone trabecular 192 has a diameter of 0.99mm, a porosity of 77.5%, and a through-porosity of 100%; The third type of bone trabecular 193 has a diameter of 1.10 mm, a porosity of 85%, and a through-porosity of 100%.

The first type of bone trabeculae 191, the second type of bone trabecular 192 and the third type of bone trabecular 193 have the same thickness, which is 3 mm.

A rectangular first solid structure 21 is arranged at the joint of the second fixing surface and the seventh fixing surface; a semicircular second solid structure 20 is arranged at the joint of the first fixing surface and the sixth fixing surface. The thickness of the solid structure 21 and the second solid structure 20 is equal to the thickness of the trabecular bone, which is 3 mm.

A side wall 22 is provided on the edge of the fixing surface formed by the medial condyle fixation surface 110 , the lateral condyle fixation surface 120 and the limit stopper 15 .

control group 1

The preparation method of cobalt alloy trabecular femoral condyle prosthesis comprises the following steps:

1) Using cobalt alloy powder as raw material, the first intermediate product is obtained by integral molding through 3D printing;

2) machining the first intermediate product, polishing, cleaning and drying to obtain a cobalt alloy trabecular femoral condyle prosthesis;

The first intermediate product has the same structure as the cobalt alloy trabecular femoral condyle prosthesis.

The cobalt alloy powder includes 65% of Co, 28% of Cr, 6% of Mo by mass percentage, and the balance is impurity elements; the particle size of the cobalt alloy powder is 75 μm.

The cobalt alloy trabecular femoral condyle prosthesis containing nitride layer includes medial condyle 11 and lateral condyle 12 arranged on the left and right, the medial condyle front end 1101 of the medial condyle 11 and the lateral condyle front end 1102 of the lateral condyle 12 are integrated, and the medial condyle 11 is integrated. The rear end portion and the rear end portion of the lateral condyle 12 are connected by a limit block 15; the lateral wall of the medial condyle 11 and the lateral wall of the lateral condyle 12 are both provided with a holding groove 16, and the medial condyle 11 has a medial condyle fixing surface 110, the outer condyle has an outer condyle fixing surface 120; the inner condyle fixing surface 110 includes the first fixing surface 111, the second fixing surface 112, the third fixing surface 113, the fourth fixing surface 114 and the fifth fixing surface 111 that are connected in turn. The fixation surface 115, the lateral condyle fixation surface 120 includes a sixth fixation surface 121, a seventh fixation surface 122, an eighth fixation surface 123, a ninth fixation surface 124 and a tenth fixation surface 125 which are connected in sequence; the third fixation surface A mounting hole 17 is provided in the middle of the surface 113 and the eighth fixing surface 123. The first fixing surface 111 and the second fixing surface 112 intersect to form a first intersection line 181; The second intersection 182; the third fixed surface 113 and the fourth fixed surface 114 intersect to form the third intersection 183; the fourth fixed surface 114 and the fifth fixed surface 115 form the fourth intersection 184; the sixth fixed surface 121 and the seventh The intersection line of the fixing surface 122 is collinear with the first intersection line 181; the intersection line of the seventh fixing surface 122 and the eighth fixing surface 123 is collinear with the second intersection line 182; The intersection line is collinear with the third intersection line 183; the intersection line of the ninth fixed surface 124 and the tenth fixed surface 125 is collinear with the fourth intersection line 184; the first intersection line 181, the second intersection line 182, the third intersection line 184 The intersection line 183 and the fourth intersection line 184 are parallel to each other;

The angle between the first fixing surface 111 and the second fixing surface 112 is equal to the angle between the sixth fixing surface 121 and the seventh fixing surface 122, which is 135°; the angle between the second fixing surface 112 and the third fixing surface 113 is equal to 135°; The angle is equal to the angle between the seventh fixing surface 122 and the eighth fixing surface 123 , which is 135°; The angles are equal, which is 135°; the angle between the fourth fixing surface 114 and the fifth fixing surface 115 is equal to the angle between the ninth fixing surface 124 and the tenth fixing surface 125, which is 135°;

The first fixing surface 111 , the fifth fixing surface 115 , the sixth fixing surface 121 and the tenth fixing surface 125 are provided with the first type of bone trabeculae 191 ;

The second fixing surface 112, the fourth fixing surface 114, the seventh fixing surface 122 and the ninth fixing surface 124 are provided with a second type of bone trabeculae 192;

The third fixing surface 113 and the eighth fixing surface 123 are provided with a third type of trabecular bone 193;

The pore size and porosity of the first type of bone trabeculae 191 are smaller than those of the second type of bone trabeculae 192 and the third type of bone trabecula 193 in turn.

The first type of trabecular bone 191 has a diameter of 0.80mm, a porosity of 72%, and a through-porosity of 100%; the second type of bone trabecular 192 has a diameter of 0.92mm, a porosity of 76%, and a through-porosity of 100%; The third type of bone trabecular 193 has a diameter of 1.05 mm, a porosity of 80%, and a through-porosity of 100%.

The first type of bone trabeculae 191, the second type of bone trabecular 192 and the third type of bone trabecular 193 have the same thickness, which is 1.7 mm.

A rectangular first solid structure 21 is arranged at the joint of the second fixing surface and the seventh fixing surface; a semicircular second solid structure 20 is arranged at the joint of the first fixing surface and the sixth fixing surface. The thickness of the solid structure 21 and the second solid structure 20 is equal to the thickness of the trabecular bone, which is 1.7 mm.

A side wall 22 is provided on the edge of the fixing surface formed by the medial condyle fixation surface 110 , the lateral condyle fixation surface 120 and the limit stopper 15 .

Experimental verification

Finite element analysis is performed on the finite element model of Example 1 of the present invention. As shown in Figures 4 to 5, the strain cloud map only shows the micro-strain (shaded part) in the range of 1000-3000. The 1000-3000 microstrain area on the finite element model accounts for 61.3% of the entire femoral condyle bone tissue finite element model, suggesting that the nitride-containing cobalt alloy bone trabecular femoral condyle prosthesis of the present invention achieves microstrain in most areas Between the minimum effective strain threshold and supraphysiological strain threshold, it has excellent bone ingrowth performance.

Scanning electron microscope (Crossbeam340/550, Zeiss, Germany) observed the trabecular bone test piece of cobalt alloy containing nitride layer in Example 1, the wire diameter was about 500 μm, and the pore diameters were 800 μm, 950 μm and 1100 μm respectively. The morphology and chemical composition of each scanning point observed by energy spectrum are shown in Figure 7. The mass percentages of each element are C: 6.17, N: 26.21, Si: 0.53, Cr: 15.17, Co: 46.68, Mo: 3.93.

Electronic universal testing machine (UTM5105, Shenzhen Sansi Zongheng Technology Co., Ltd., China) was used to test the solid tensile test piece prepared by the same preparation method described in Example 1 and the solid tensile test piece prepared by the same preparation method described in Control Group 1. Tensile performance test (refer to standard GB/T 228.1-2010), there are 12 solid tensile test pieces in Example 1 and Control Group 1 each. The results are shown in Table 1. Compared with the control group 1, the maximum force of Example 1 is close (P>0.05), and the tensile strength and elastic modulus are slightly lower than those of the control group 1, but there is no statistical difference (P>0.05). P>0.05); the prescribed non-proportional elongation strength of Example 1 is lower than that of control group 1 (P<0.05), and the elongation and reduction of section of Example 1 are better than those of control group 1 (P<0.05), suggesting that the present invention The 3D printed cobalt alloy tensile test bar prepared by hot isostatic pressing has stronger plasticity than the tensile test bar prepared without hot isostatic pressing, and the fatigue resistance of the cobalt alloy femoral condyle prepared by this process is enhanced.

n＝12，*P＜0.05，与对照组1比较)Table 1 The tensile test results of the solid tensile test pieces of the control group 1 and Example 1 (

n=12, *P<0.05, compared with control group 1)

Mouse MC3T3-E1 cells were seeded in ^75cm2 culture flasks and cultured in a 37°C, 5% _CO2 incubator. After trypsinization, the cell suspension at a density of 2×10 ⁶ was inoculated on the first, second and third trabecular bone test pieces and control group 1 containing the nitride layer. Each trabecular bone test piece was inoculated with 20 μl, incubated at 37°C for 30 min, the test piece was turned over, incubated for 3 h, α-MEM medium (containing 10% fetal bovine serum and 1% double antibody) was added, and the medium was changed every 2 days. The cell-trabecular bone test piece complex was cultured for 7 days and taken out for MTT proliferation experiment. According to the operating instructions, the OD value was measured at 450 nm (TECAN, Austria), using SPSS statistical software

- Statistical analysis of experimental data. The data were expressed as (x±s), the comparison between groups was performed by one-way ANOVA, and the pairwise comparison was performed by LSD method. The mean OD values were 0.60, 0.67, and 0.86, respectively. The three kinds of trabecular bone test pieces containing nitrided layer had obvious effect on cell proliferation, and the difference was statistically significant (P<0.05).

Experiments have proved that the mechanical properties of the solid part of the cobalt alloy trabecular femoral condyle prosthesis containing nitrided layer prepared in Examples 2 and 3, the chemical composition, morphology and biocompatibility of the nitrided layer of the trabecular part of the bone are the same as the examples. 1 The cobalt alloy trabecular femoral condyle prosthesis prepared with nitride layer is similar.

Claims (9)

1. a preparation method of a nitrided layer cobalt alloy bone trabecular femoral condyle prosthesis is characterized by comprising the steps: 1) Using cobalt alloy powder as raw material, the first intermediate product is obtained by integral molding through 3D printing, and the first intermediate product is put into a hot isostatic pressing furnace, and is heated to 1165 ℃ - 1170 ℃ under the protection of inert gas, and the temperature is 130MPa-140MPa, placed at a constant temperature for 1h-3h, lowered to normal pressure, cooled to room temperature with the furnace, taken out to obtain the second intermediate product; 2) use deionized water and absolute ethanol successively to carry out ultrasonic cleaning to the second intermediate product, remove surface impurities, and dry; put into the vacuum chamber of the plasma immersion implanter, and vacuumize; negative high pressure, the injection volume ratio is (2- 1): the mixture of nitrogen and argon of 1, the injection time is 5min-45min, after the injection is completed, take out to obtain the third intermediate product; 3) carrying out machining trimming, polishing, cleaning and drying on the third intermediate product to obtain a cobalt-containing nitride-layer trabecular femoral condyle prosthesis; The first intermediate product, the second intermediate product, and the third intermediate product have the same structure as the nitrided-layer cobalt alloy bone trabecular femoral condyle prosthesis. 2. The method for preparing a cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer according to claim 1, wherein the cobalt alloy powder comprises 60%-67% Co, 27%-30% Co by mass percentage % Cr, 5%-7% Mo, and the balance is impurity elements; the particle size of the cobalt alloy powder is 45 μm-106 μm. 3. the preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing nitrided layer according to claim 1, is characterized in that described step 2) is: use deionized water and absolute ethanol successively to the second intermediate product Carry out ultrasonic cleaning, remove surface impurities, and dry; put it into the vacuum chamber of the plasma immersion implanter, and evacuate to 5*10 ^-4 Pa; the negative high voltage is 10kV-15kV, and the injection volume ratio is (2-1): 1 The mixed gas of nitrogen and argon, the injection time is 5min-45min, after the injection is completed, it is taken out to obtain the third intermediate product. 4. The preparation method of the cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer according to claim 1, characterized in that the cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer comprises the inner side arranged on the left and right sides. The condyle (11) and the lateral condyle (12), the medial condyle front end (1101) of the medial condyle (11) and the lateral condyle front end (1102) of the lateral condyle (12) are integrated, and the rear end of the medial condyle (11) is integrated with the lateral The rear end of the condyle (12) is connected by a limit stopper (15); the outer side wall of the inner condyle (11) and the outer side wall of the outer condyle (12) are both provided with a holding groove (16), and the inner condyle (12) is provided with a holding groove (16). 11) have inner condyle fixation surface (110), described outer condyle has outer condyle fixation surface (120); Described inner condyle fixation surface (110) comprises the first fixation surface (111), the second fixation surface (111) that are connected successively 112), the third fixation surface (113), the fourth fixation surface (114) and the fifth fixation surface (115), the lateral condyle fixation surface (120) comprises the sixth fixation surface (121), the seventh fixation surface (121) and the seventh The fixing surface (122), the eighth fixing surface (123), the ninth fixing surface (124) and the tenth fixing surface (125); the third fixing surface (113) and the eighth fixing surface (123) are provided with an installation hole (17), the first fixing surface (111) and the second fixing surface (112) intersect to form a first intersection line (181); the second fixing surface (112) and the third fixing surface (113) intersect to form The second intersection (182); the third fixed surface (113) and the fourth fixed surface (114) intersect to form a third intersection (183); the fourth fixed surface (114) and the fifth fixed surface (115) form the first Four intersection lines (184); the intersection of the sixth fixed surface (121) and the seventh fixed surface (122) is collinear with the first intersection (181); the seventh fixed surface (122) and the eighth fixed surface (123) ) is collinear with the second intersection (182); the intersection of the eighth fixed surface (123) and the ninth fixed surface (124) is collinear with the third intersection (183); the ninth fixed surface (124) ) and the intersection of the tenth fixed surface (125) and the fourth intersection (184) are collinear; the first intersection (181), the second intersection (182), the third intersection (183) and the The quadrature lines (184) are parallel to each other; The included angle between the first fixing surface (111) and the second fixing surface (112) is equal to the included angle between the sixth fixing surface (121) and the seventh fixing surface (122), which is 130°-140°; The included angle between the fixing surface (112) and the third fixing surface (113) is equal to the included angle between the seventh fixing surface (122) and the eighth fixing surface (123), which is 130°-140°; the third fixing surface (113) ) and the fourth fixing surface (114) and the angle between the eighth fixing surface (123) and the ninth fixing surface (124) are equal to 130°-140°; the fourth fixing surface (114) and the fifth The included angle of the fixing surface (115) is equal to the included angle between the ninth fixing surface (124) and the tenth fixing surface (125), which is 130°-140°; The first fixation surface (111), the fifth fixation surface (115), the sixth fixation surface (121) and the tenth fixation surface (125) are provided with a first type of bone trabecular (191); The second fixation surface (112), the fourth fixation surface (114), the seventh fixation surface (122) and the ninth fixation surface (124) are provided with a second type of bone trabecular (192); The third fixation surface (113) and the eighth fixation surface (123) are provided with a third type of bone trabecular (193); The pore size and porosity of the first type of bone trabeculae (191) are sequentially smaller than those of the second type of bone trabecula (192) and the third type of bone trabecula (193). 5. The method for preparing a cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer according to claim 4, wherein the first type of trabecular bone (191) has a diameter of 0.74mm-0.85mm, and a pore diameter of 0.74mm-0.85mm. The rate is 70.0%-74.7%, and the through hole rate is 100%; The second trabecular bone (192) has a diameter of 0.86mm-0.99mm, a porosity of 74.8%-77.5%, and a through-porosity of 100%; The third trabecular bone (193) has a diameter of 1.00mm-1.10mm, a porosity of 77.6%-85%, and a through-porosity of 100%. 6. The method for preparing a trabecular bone femoral condyle prosthesis containing nitrided layer cobalt alloy according to claim 4, wherein the first type of trabecular bone (191) and the second type of trabecular bone (192) ) and the third trabecular bone (193) are equal in thickness, ranging from 0.5mm to 3mm. 7. The method for preparing a cobalt alloy trabecular femoral condyle prosthesis containing a nitride layer according to claim 4, wherein a rectangular first A solid structure (21); a semicircular second solid structure (20) is provided at the joint of the first fixing surface and the sixth fixing surface, and the thicknesses of the first solid structure (21) and the second solid structure (20) are It is equal to the thickness of trabecular bone and is 0.5mm-3mm. 8. The method for preparing a cobalt-alloy trabecular femoral condyle prosthesis containing a nitride layer according to claim 4, characterized in that, in the medial condyle fixation surface (110), the lateral condyle fixation surface (120) and the limit stop The edge of the fixing surface formed by the block (15) is provided with side walls (22). 9 . A cobalt-containing trabecular femoral condyle prosthesis prepared according to the method for preparing a trabecular femoral condyle prosthesis containing nitrided-layer cobalt alloys according to claim 1 .

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