CN111467091A - Tibial tray prosthesis - Google Patents

Abstract

The present invention relates to a tibial tray prosthesis, which is characterized in that the tibial tray prosthesis has an anterior-posterior diameter A and a left-right diameter B, and the anterior-posterior diameter A increases as the left-right diameter B increases, The ratio A/B of the front-rear diameter A to the left-right diameter B shows a decreasing trend as the left-right diameter B increases. The tibial tray prosthesis can be closer to the anatomical shape of the human knee joint tibia, thereby improving the coverage of the tibial prosthesis and reducing the prosthesis loosening and the probability of postoperative pain of the patient.

Description

tibial tray prosthesis

technical field

The invention relates to the technical field of medical devices, in particular to a tibial tray prosthesis.

Background technique

Unicondylar replacement surgery uses a micro-traumatic incision and can preserve the anterior and posterior cruciate ligaments of the knee joint. It has the advantages of less trauma, quick recovery, and good postoperative physiological activity. Therefore, unicondylar replacement surgery is widely used in single-compartment. in the treatment of osteoarthritis. Unicondylar prostheses used in unicondylar replacement can be divided into medial femoral prosthesis and medial tibial prosthesis for replacing the medial compartment, and lateral femoral prosthesis and lateral tibial prosthesis for replacing the lateral compartment.

Prosthesis loosening and postoperative pain are the main reasons for revision of unicondylar knee replacement, and poor prosthesis coverage is an important cause of prosthesis loosening and postoperative pain. Poor prosthesis coverage means that the prosthesis cannot adequately cover the cortical bone area. , so that the prosthesis cannot be well supported, which may easily lead to the subsidence and loosening of the prosthesis after surgery, the prosthesis overhanging and interfering with the surrounding soft tissue, thereby causing postoperative pain.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a knee joint system, a tibial prosthesis and a tibial tray prosthesis in order to improve the coverage of the tibial prosthesis, reduce the postoperative loosening of the prosthesis and the probability of postoperative pain.

A tibial tray prosthesis, the tibial tray prosthesis is used to replace the medial compartment of the tibia of a human knee joint, the tibial tray prosthesis has an anterior-posterior diameter A and a left-right diameter B, and the anterior-posterior diameter A follows the left-right diameter A. As the diameter B increases, the ratio A/B of the front-rear diameter A to the left-right diameter B presents a decreasing trend.

By setting the ratio A/B of the anteroposterior diameter A and the left and right diameter B of the tibial tray prosthesis to a decreasing trend with the increase of the left and right diameter B, the tibial tray prosthesis can be closer to the anatomical shape of the inner side of the tibia of the human knee joint. , thereby improving the coverage of the tibial prosthesis, reducing the probability of prosthesis loosening and postoperative pain.

In one embodiment, the ratio A/B of the front-rear diameter A to the left-right diameter B ranges from 1.6 to 2.0.

In one embodiment, the ratio A/B of the front-rear diameter A to the left-right diameter B and the left-right diameter B satisfy A/B=-k1×B+x, where 0.018<k1<0.020, 2.17< x<2.47.

In one embodiment, the ratio A/B of the front-rear diameter A to the left-right diameter B is within a range of 0.15 above and below the straight line represented by A/B=-0.019×B+2.32.

In one embodiment, the ratio A/B of the front-rear diameter A to the left-right diameter B presents a linear decreasing trend with the increase of the left-right diameter B, and the front-rear diameter A and the left-right diameter B The relationship between the ratio A/B of , and the left and right diameter B satisfies A/B=-k1×B+x, where 0.018<k1<0.020 and 2.17<x<2.47.

In one embodiment, the tibial tray prosthesis has a first side surface and a second side surface disposed opposite to each other, the second side surface is a straight surface, and the point on the first side surface farthest from the second side surface is The vertical distance of the front tangent line is denoted as the first distance C, the ratio C/A of the first distance C to the front and rear diameter A is in the range of 0.45-0.75, and the front tangent line is perpendicular to the second side and A line tangent to the contour of the front end of the tibial tray prosthesis.

In one embodiment, the first side surface includes a leading edge curved surface and a trailing edge curved surface, and the ratio R1/A of the curvature radius R1 of the leading edge curved surface to the front and rear diameter A ranges from 0.45 to 0.7; The ratio R2/A of the curvature radius R2 of the edge curved surface to the front and rear diameters A ranges from 0.25 to 0.45.

In one embodiment, the first side surface further includes a straight surface segment, two ends of the straight surface segment are respectively connected to the leading edge curved surface and the trailing edge curved surface, and the length E of the straight surface segment is related to the front and rear diameters. The ratio of A, E/A, is in the range of 0.07-0.12.

In one embodiment, the tibial tray prosthesis further includes a straight posterior edge surface, two ends of the straight posterior edge surface are respectively connected to the posterior edge curved surface and the second side surface, and the length of the posterior edge straight surface D= B-R2.

In one embodiment, the second side surface is a straight surface, and when the tibial tray prosthesis is in the theoretical implantation position, the first side surface is perpendicular to the transcondylar axis of the knee joint.

A tibial tray prosthesis, the tibial tray prosthesis is used to replace the lateral compartment of the tibia of a human knee joint, the tibial tray prosthesis has an anterior-posterior diameter a and a left-right diameter b, and the anterior-posterior diameter a follows the left and right diameters. As the diameter b increases, the ratio a/b of the front-rear diameter a and the left-right diameter b presents a decreasing trend with the increase of the left-right diameter b.

In one embodiment, the ratio a/b of the front-rear diameter a to the left-right diameter b is in the range of 1.4-1.8.

In one embodiment, the relationship between the ratio a/b of the front-rear diameter a and the left-right diameter b and the left-right diameter b satisfies a/b=-k2×b+y, where 0.019<k2<0.021, 2.04<y<2.34.

In one embodiment, the ratio a/b of the front-rear diameter a and the left-right diameter b is within a range of 0.15 above and below the straight line represented by a/b=-0.02×b+2.19.

In one embodiment, the ratio a/b of the front-rear diameter a to the left-right diameter b shows a linear decreasing trend as the left-right diameter b increases, and the front-rear diameter a and the left-right diameter b The relationship between the ratio a/b of , and the left and right diameter b satisfies a/b=-k2×b+y, where 0.019<k2<0.021, 2.04<y<2.34.

In one embodiment, the tibial tray prosthesis has a first side surface and a second side surface arranged opposite to each other, the second side surface is a straight surface, and the first side surface is farthest from the second side surface to the front end The vertical distance of the tangent is denoted as the second distance c, and the ratio c/a of the second distance c to the front and rear diameter a ranges from 0.45 to 0.6. The tibial tray prosthesis is a straight line tangent to the contour of the front end of the prosthesis.

In one embodiment, the first side surface includes a leading edge curved surface and a trailing edge curved surface, and the ratio r1/A of the curvature radius r1 of the leading edge curved surface to the front and rear diameter a ranges from 0.35 to 0.65; The ratio r2/a of the curvature radius r2 of the edge curved surface to the front and rear diameter a ranges from 0.4 to 0.6.

In one embodiment, the first side surface further includes a straight surface segment, two ends of the straight surface segment are respectively connected to the leading edge curved surface and the trailing edge curved surface, and the length e of the straight surface segment is related to the front and rear diameters. The ratio e/a of a ranges from 0.09 to 0.12. The "straight surface" or "straight line" mentioned in the present invention is not a straight surface or a straight line in the mathematical sense, but refers to a straight surface or a straight line in an engineering sense that meets certain error requirements.

By setting the ratio A/B of the anteroposterior diameter A and the left and right diameter B of the tibial tray prosthesis to a decreasing trend with the increase of the left and right diameter B, the tibial tray prosthesis can be closer to the anatomical shape of the inner side of the tibia of the human knee joint. , thereby improving the coverage of the tibial prosthesis, reducing the probability of prosthesis loosening and postoperative pain.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a tibial tray prosthesis according to an embodiment;

Fig. 2 is an example table of the anterior-posterior diameter A, the left-right diameter B and the ratio A/B of the tibial tray prosthesis shown in Fig. 1;

3 is a schematic structural diagram of a tibial tray prosthesis of another embodiment;

Fig. 4 is an example table of the anterior-posterior diameter a, the left-right diameter b and the ratio a/b of the tibial tray prosthesis shown in Fig. 3;

FIG. 5 is a schematic view of the installation of the tibial tray prosthesis according to an embodiment.

Description of reference numbers:

100. Tibial tray prosthesis; 10. Curved surface of anterior edge; 11. Straight surface segment; 12. Curved surface of posterior edge; 13. Straight surface of posterior edge; , straight face segment; 22, trailing edge curved surface; 23, trailing edge straight surface; 24, second side.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

In order to better illustrate the technical solutions of the present invention, the orientation names involved in each embodiment are first explained:

Sagittal plane: refers to the longitudinal section that divides the human body or prosthesis into left and right parts from the anterior and posterior directions. Two equal parts left and right.

Coronal plane: refers to the longitudinal section that divides the human body or prosthesis into front and rear parts from the left and right directions, and the section is perpendicular to the sagittal plane.

Transverse plane: also known as the horizontal plane, is a plane parallel to the ground plane that divides the human body or prosthesis into upper and lower parts, and this plane is perpendicular to the coronal and sagittal planes.

Medial: The side relatively close to the midsagittal plane of the human body.

Lateral: The side relatively far from the midsagittal plane of the human body.

Anterior: The side of the sagittal plane that is relatively close to the abdomen.

Posterior: The side relatively close to the back in the sagittal plane.

Referring to FIG. 1, FIG. 1 shows a top view of a tibial tray prosthesis 100 in an embodiment of the present invention. Specifically, as shown in FIG. 5, the tibial tray prosthesis 100 is used to replace the medial compartment of the left knee tibia, It should be noted that the mirror image of the tibial tray prosthesis 100 can be used to replace the medial tibial compartment of the right knee joint.

The tibial tray prosthesis 100 includes an opposite front end and a rear end. From the orientation of being implanted in the human body, the front end is close to the abdomen of the human body, and the rear end is close to the back of the human body. Further, the tibial tray prosthesis 100 further includes a first side surface and a second side surface 14 which are disposed opposite to each other. Viewed from the orientation of its implantation into the human body, the first side face is close to the midsagittal plane of the human body and is the inner edge of the tibial tray prosthesis 100 , and the second side face 14 is far from the midsagittal plane of the human body and is the outer edge of the tibial tray prosthesis 100 . Further, the first side of the tibial tray prosthesis 100 is a curved surface that protrudes away from the second side 14 , and the second side 14 of the tibial tray prosthesis 100 is a straight surface, so the first side of the tibial tray prosthesis 100 has The point farthest from the second side surface 14 , the vertical distance from the point to the second side surface 14 is the left and right diameter B of the tibial tray prosthesis 100 .

In the extending direction of the second side surface 14 , the maximum length of the tibial tray prosthesis 100 is the anteroposterior diameter A of the tibial tray prosthesis 100 . In other words, it is assumed that a line perpendicular to the second side surface 14 is tangent to the contour of the front end of the tibial tray prosthesis 100 (hereinafter this tangent is referred to as an anterior tangent line), and a line perpendicular to the second side surface 14 is tangent to the contour of the rear end of the tibial tray prosthesis 100 (The tangent is referred to as the rear tangent hereinafter), the vertical distance between the front tangent and the rear tangent is the anteroposterior diameter A of the tibial tray prosthesis 100 .

Further, referring to FIG. 2 , FIG. 2 shows an example table of the anterior-posterior diameter A, the left-right diameter B and the ratio A/B of a group of tibial tray prostheses 100 with varying sizes from small to large. Specifically, the ratio A/B of the anterior-posterior diameter A to the left-right diameter B of the tibial tray prosthesis 100 ranges from 1.6 to 2.0, and the anterior-posterior diameter A of the tibial tray prosthesis 100 tends to increase with the increase of the left-right diameter B. On the other hand, the ratio A/B of the anterior-posterior diameter A to the left-right diameter B of the tibial tray prosthesis 100 shows a decreasing trend as the left-right diameter B increases. For example, as shown in FIG. 2 , the value of the anteroposterior diameter A of the smallest tibial tray prosthesis 100 is 37.1 mm, the value of the left and right diameter B is 19 mm, and A/B is 1.95; the anteroposterior diameter A of the largest tibial tray prosthesis 100 The value of 57.5mm, the value of the left and right diameter B is 35.5mm, and the value of A/B is 1.62.

In view of the shortcomings such as insufficient coverage and easy loosening of the traditional radial bone support prosthesis, our research and development personnel have been surprised to find that the bone surface ratio of the medial and lateral tibial condyle ( That is, the ratio of the anteroposterior diameter of the femur to the left and right diameters) is inversely correlated with the size of the tibia. Therefore, the ratio A/B of the anterior and posterior diameters of the tibial tray prosthesis 100 to the left and right diameters B is set to increase with the increase of the left and right diameters B. With a decreasing trend, the tibial tray prosthesis 100 can be closer to the anatomical shape of the medial tibia of the human knee joint, thereby improving the coverage of the tibial prosthesis and reducing the prosthesis loosening and the probability of postoperative pain of the patient.

Further, the relationship between the ratio A/B of the front-rear diameter A and the left-right diameter B and the left-right diameter B satisfies A/B=-k1×B+x, where 0.018<k1<0.020, 2.17<x< 2.47, preferably k1=0.019, x=2.32. Alternatively, the value of A/B is within the range of 0.15 above and below the straight line represented by A/B=-0.019×B+2.32. That is, for the selected B, the value of A/B is in the range of (-0.019×B+2.32)±0.15. Further, in a more ideal situation, the ratio A/B of the front-rear diameter A to the left-right diameter B shows a linear decreasing trend with the increase of the left-right diameter B, and the front-rear diameter A and the The relationship between the ratio A/B of the left and right diameters B and the left and right diameters B satisfies A/B=-k1×B+x, where 0.018<k1<0.020, 2.17<x<2.47, preferably k1=0.019, x=2.32. Understandably, considering that there will be manufacturing errors in the manufacturing process of the product, within the allowable range of errors, for example, when the ratio A/B of the front and rear diameter A and the left and right diameter B is within the deviation of ±0.01, it can still be regarded as meeting the above relationship. .

Further, the vertical distance from the point farthest from the second side surface 14 on the first side of the tibial tray prosthesis 100 (hereinafter referred to as the farthest point) to the tangent to the front end of the tibial tray prosthesis 100 is denoted as the first The distance C, and the ratio C/A of the first distance C to the front-to-back diameter A is in the range of 0.45-0.75, preferably 0.55-0.62. After research and statistical analysis of the anatomical data of the human knee joint, our research and development personnel found that the positions of the farthest points of the medial femoral condyle and the lateral condyle of the human knee joint are not the same. The farthest point of the medial condyle Closer to the posterior end of the medial condyle, the farthest point of the lateral condyle is closer to the middle of the medial condyle, yet traditional tibial component designs rarely take into account the aforementioned anatomical differences in the shape of the medial and lateral tibia. Therefore, in the present application, by setting the ratio C/A of the first distance C to the anteroposterior diameter in the range of 0.45-0.75, preferably 0.53-0.63, the tibial tray prosthesis 100 is closer to the anatomical shape of the inner side of the tibia of the human knee joint, thereby improving the The coverage of the tibial prosthesis reduces the probability of prosthesis loosening and postoperative pain.

Further, along the direction from the front end to the rear end of the tibial tray prosthesis 100, the first side surface includes an anterior edge curved surface 10, a straight surface segment 11 and a posterior edge curved surface 12 connected in sequence, and the curvature radius R1 of the anterior edge curved surface 10 and the anterior-posterior diameter A are The ratio R1/A is in the range of 0.45-0.7, preferably 0.55-0.63, and the ratio R2/A of the radius of curvature R2 of the trailing edge curved surface 12 to the front and rear diameter A is in the range of 0.25-0.45, preferably 0.28-0.36. The ratio E/A of the length E of the straight face section 11 to the front and rear diameter A ranges from 0.07 to 0.12, where the length E of the straight face section 11 refers to the length of the line segment formed after the straight face section 11 intersects the horizontal plane. After research and statistical analysis of the anatomical data of the human knee joint, our research and development personnel found that the medial femoral condyle of the human knee joint is an asymmetric "D"-shaped structure, that is, the anterior surface of the medial femoral condyle of the human knee joint. The radius of curvature of 10 is relatively large, and the radius of curvature of the anterior curved surface 10 is relatively small. The ratio of the anteroposterior diameter A makes the tibial tray prosthesis 100 closer to the anatomical shape of the medial tibia of the knee joint of the human body, thereby improving the coverage of the tibial prosthesis and reducing the probability of prosthesis loosening and postoperative pain of the patient.

Further, the tibial tray prosthesis 100 also includes a straight rear edge surface 13, two ends of which are respectively connected to the rear edge curved surface 12 and the second side surface 14, and the length D of the rear edge straight surface 13 is equal to the left and right diameter B and the rear edge curved surface 12. The difference of the radius of curvature R2 of , namely D=B-R2, where the length D of the straight surface 13 of the trailing edge refers to the length of the line segment formed after the straight surface 13 of the trailing edge intersects the horizontal plane.

Further, the second side surface 14 is a straight surface, and when the tibial tray prosthesis 100 is in the theoretical implant position, the second side surface 14 is perpendicular or approximately perpendicular to the transcondylar axis TEA of the knee joint.

Further, the present application also provides a tibial tray prosthesis 200 of another embodiment. Referring to FIG. 3 , FIG. 3 shows a top view of a tibial tray prosthesis 200 in another embodiment of the present invention. Specifically, as shown in FIG. 5 , the tibial tray prosthesis 200 is used to replace the lateral compartment of the left knee tibia , It is worth noting that the mirror image of the tibial tray prosthesis 200 can be used to replace the lateral tibial compartment of the right knee joint.

The tibial tray prosthesis 200 has an opposite front end and a rear end. From the orientation of being implanted into the human body, the front end is close to the abdomen of the human body, and the rear end is close to the back of the human body. Further, the tibial tray prosthesis 200 further includes a first side surface and a second side surface 24 which are arranged opposite to each other. Viewed from the orientation of its implantation in the human body, the first side face is away from the midsagittal plane of the human body and is the outer edge of the tibial tray prosthesis 200, and the second side face 24 is close to the midsagittal plane of the human body and is the outer edge of the tibial tray prosthesis 200. inside edge. Further, the first side of the tibial tray prosthesis 200 is a curved surface that protrudes away from the second side 24, and the second side 24 of the tibial tray prosthesis 200 is a straight surface, so the first side of the tibial tray prosthesis 200 has The point farthest from the second side surface 24 , the vertical distance from the point to the second straight surface is the left and right diameter b of the tibial tray prosthesis 200 .

In the extending direction of the second side surface 24 , the maximum length of the tibial tray prosthesis 200 is the anteroposterior diameter a of the tibial tray prosthesis 200 . In other words, it is assumed that a line perpendicular to the second side surface 24 is tangent to the contour of the front end of the tibial tray prosthesis 200 (hereinafter this tangent is referred to as an anterior tangent line), and a line perpendicular to the second side surface 24 is tangent to the contour of the rear end of the tibial tray prosthesis 200 (The tangent is referred to as the rear tangent below), the vertical distance between the front tangent and the rear tangent is the anteroposterior diameter a of the tibial tray prosthesis 200 .

Further, referring to FIG. 4 , FIG. 4 shows an example table of the anterior-posterior diameter a, the left-right diameter b and the ratio a/b of a group of tibial tray prostheses 200 whose sizes vary from small to large. Specifically, the ratio a/b of the anterior-posterior diameter a to the left-right diameter b of the tibial tray prosthesis 200 ranges from 1.4 to 1.8, and the anterior-posterior diameter a of the tibial tray prosthesis 200 tends to increase with the increase of the left-right diameter b. The ratio a/b of the anterior-posterior diameter a to the left-right diameter b of the tibial tray prosthesis 200 presents a decreasing trend as the left-right diameter b increases. For example, as shown in FIG. 4 , the value of the anteroposterior diameter a of the smallest size tibial tray prosthesis 100 is 38.7 mm, the value of the left and right diameter b is 22 mm, and a/b is 1.76, and the anteroposterior diameter a of the largest size tibial tray prosthesis 100 The value of 54mm, the value of the left and right diameter b is 37mm, and the value of a/b is 1.46.

In view of the shortcomings such as insufficient coverage and easy loosening of the traditional radial bone support prosthesis, our research and development personnel have been surprised to find that the bone surface ratio of the medial and lateral tibial condyle ( That is, the ratio of the anteroposterior diameter of the femur to the left and right diameters) is inversely correlated with the size of the tibia. Therefore, by setting the ratio a/b of the anterior and posterior diameters a to the left and right diameters of the tibial tray prosthesis 200 to increase with the increase of the left and right diameters b. With a decreasing trend, the tibial tray prosthesis 200 can be closer to the anatomical shape of the inner side of the tibia of the human knee joint, thereby improving the coverage rate of the tibial prosthesis and reducing the prosthesis loosening and the probability of postoperative pain of the patient.

Further, the relationship between the ratio a/b of the front-rear diameter a and the left-right diameter b and the left-right diameter b satisfies a/b=-k2×b+y, where 0.019<k2<0.021, 2.04<y< 2.34, preferably k1=0.020, y=2.19. Alternatively, the value of a/b is within a range of 0.15 above and below the straight line represented by a/b=−0.02×b+2.19. That is, for the selected b, the value of a/b is in the range of (−0.02×b+2.19)±0.15. Further, in a more ideal situation, the ratio a/b of the front and rear diameter a to the left and right diameter b presents a linear decreasing trend with the increase of the left and right diameter b, and the front and rear diameter a and the The relationship between the ratio a/b of the left-right diameter b and the left-right diameter b satisfies a/b=-k2×b+y, where 0.019<k2<0.021, 2.04<y<2.34, preferably k1=0.020, y=2.19. Understandably, considering that there will be manufacturing errors in the manufacturing process of the product, within the allowable range of errors, for example, when the ratio a/b of the front and rear diameter a and the left and right diameter b is within a deviation of ±0.01, it can still be regarded as meeting the above relationship. .

Further, the vertical distance from the point farthest from the second side surface 24 on the first side of the tibial tray prosthesis 200 (hereinafter referred to as the farthest point) to the tangent to the front end of the tibial tray prosthesis 200 is denoted as the first distance c, and the first The ratio c/a of a distance c to the front-to-back diameter a is in the range of 0.45-0.6, preferably 0.48-0.53. After researching the anatomical data of human knee joint and conducting statistical analysis on the anatomical data, our research and development personnel found that the positions of the farthest point of the medial femoral condyle and the lateral condyle of the human knee joint are not the same, and the farthest point of the medial condyle is closer The posterior end of the medial condyle, the farthest point of the lateral condyle is closer to the middle of the medial condyle, however traditional tibial prosthesis designs have few anatomical differences in the shape of the medial and lateral tibia described above. Therefore, in the present application, by setting the ratio c/a of the first distance c to the anteroposterior diameter a to 0.45-0.6, preferably 0.48-0.53, the tibial tray prosthesis 200 is closer to the anatomical shape of the lateral tibia of the human knee joint, thereby Improve the coverage of tibial prosthesis, reduce prosthesis loosening and the probability of postoperative pain in patients.

Further, along the direction from the front end to the rear end of the tibial tray prosthesis 200, the first side surface includes an anterior edge curved surface 20, a straight surface segment 21 and a posterior edge curved surface 22 connected in sequence, and the curvature radius r1 of the anterior edge curved surface 20 and the anterior and posterior diameter a The ratio r1/a is in the range of 0.35-0.65, preferably 0.38-0.51, and the ratio r2/a of the curvature radius r2 of the trailing edge curved surface 22 to the front and rear diameter a is in the range of 0.4-0.6, preferably 0.45-0.55. The ratio e/a of the length e of the straight face section 21 to the front and rear diameter a ranges from 0.09 to 0.12. Here, the length e of the straight surface segment 21 refers to the length of the line segment formed by the straight surface segment 21 intersecting the horizontal plane. After research and statistical analysis of the anatomical data of the human knee joint, our research and development personnel found that the lateral femoral condyle of the human knee joint is an approximately symmetrical semicircular structure. The ratio of the radius of curvature r1 to the anterior-posterior diameter a and the ratio of the curvature radius r2 of the posterior edge curved surface 22 to the anterior-posterior diameter a make the tibial tray prosthesis 200 closer to the anatomical shape of the lateral tibia of the human knee joint, thereby improving the tibial prosthesis Coverage, reducing prosthesis loosening and the probability of postoperative pain for the patient.

Further, as shown in FIG. 3 , when the tibial tray prosthesis 200 is in the theoretical implantation position, the second side surface 24 forms an angle β with the transcondylar axis TEA of the knee joint, and the angle β ranges from 60° to 80°. .

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Back, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device or Elements must have a particular orientation, be constructed and operate in a particular orientation and are therefore not to be construed as limitations of the invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or an intervening element may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Claims (17)

1. A tibial tray prosthesis for replacing the medial tibial compartment of a human knee joint, the tibial tray prosthesis having a sagittal diameter a and a lateral diameter B, the sagittal diameter a increasing with increasing lateral diameter B, and a ratio a/B of the sagittal diameter a to the lateral diameter B decreasing with increasing lateral diameter B.

2. The tibial tray prosthesis of claim 1, wherein the ratio a/B of the anterior-posterior diameter a to the left-right diameter B is in the range of 1.6-2.0.

3. The tibial tray prosthesis of claim 1, wherein the ratio of the anteroposterior diameter a to the left and right diameters B, a/B, and the left and right diameters B satisfy a/B ═ k1 × B + x, where 0.018 < k1 < 0.020, and 2.17 < x < 2.47.

4. The tibial tray prosthesis of claim 1 wherein the ratio a/B of the anteroposterior diameter a to the left and right diameter B is in the range of-0.019 × B +2.32, up and down, 0.15.

5. The tibial tray prosthesis of claim 1, wherein the ratio a/B of the anteroposterior diameter a to the left and right diameters B decreases linearly with increasing left and right diameters B, and the relationship between the ratio a/B of the anteroposterior diameter a to the left and right diameters B and the left and right diameters B satisfies a/B ═ k1 × B + x, where 0.018 < k1 < 0.020 and 2.17 < x < 2.47.

6. The tibial tray prosthesis of claim 1, wherein the tibial tray prosthesis has a first side and a second side opposite to the first side, the second side being straight, a perpendicular distance from a point on the first side furthest from the second side to an anterior tangent line, denoted as a first distance C, a ratio C/a of the first distance C to the anterior-posterior diameter a being in a range of 0.45-0.75, the anterior tangent line being a line perpendicular to the second side and tangential to an anterior profile of the tibial tray prosthesis.

7. The tibial tray prosthesis of claim 6, wherein said first lateral surface comprises an anterior curvature and a posterior curvature, said anterior curvature having a radius of curvature R1 over said anterior-posterior diameter a ratio R1/a ranging from 0.45-0.7; the ratio R2/A of the curvature radius R2 of the trailing edge curved surface to the front-to-rear diameter A ranges from 0.25 to 0.45.

8. The tibial tray prosthesis of claim 7, wherein said first lateral surface further comprises a straight surface segment, said straight surface segment having two ends connected to said leading curved surface and said trailing curved surface, respectively, and a ratio E/a of a length E of said straight surface segment to said anterior-posterior diameter a is in a range of 0.07-0.12.

9. The tibial tray prosthesis of claim 7, further comprising a trailing straight surface having two ends connected to the trailing curved surface and the second side surface, respectively, wherein the length D of the trailing straight surface is B-R2.

10. A tibial tray prosthesis for replacing the lateral tibial compartment of a human knee joint, the tibial tray prosthesis having an anteroposterior diameter a and a lateral right and left diameter b, the anteroposterior diameter a increasing with increasing the lateral right and left diameter b, the ratio a/b of the anteroposterior diameter a to the lateral right and left diameter b decreasing with increasing the lateral right and left diameter b.

11. The tibial tray prosthesis of claim 10, wherein the ratio a/b of the anteroposterior diameter a to the left and right diameters b is in the range of 1.4-1.8.

12. The tibial tray prosthesis of claim 10, wherein the ratio of the anterior-posterior diameter a to the left-right diameter b, a/b, to the left-right diameter b satisfies a/b-k 2 × b + y, where 0.019 < k2 < 0.021, and 2.04 < y < 2.34.

13. The tibial tray prosthesis of claim 10 wherein the ratio a/b of the anterior-posterior diameter a to the left-right diameter b is in the range of-0.02 × b +2.19, up and down, 0.15.

14. The tibial tray prosthesis of claim 10, wherein the ratio a/b of the anteroposterior diameter a to the left and right diameters b decreases linearly with increasing left and right diameters b, and the relationship between the ratio a/b of the anteroposterior diameter a to the left and right diameters b and the left and right diameters b satisfies a/b-k 2 × b + y, wherein 0.019 < k2 < 0.021, and 2.04 < y < 2.34.

15. The tibial tray prosthesis of claim 10, wherein the tibial tray prosthesis has a first side and a second side opposite to each other, the second side is a straight side, a perpendicular distance from a point of the first side farthest from the second side to an anterior tangent line is denoted as a second distance c, a ratio c/a of the second distance c to the anterior-posterior diameter a is in a range of 0.45-0.6, and the anterior tangent line is a straight line perpendicular to the second side and tangential to an anterior profile of the tibial tray prosthesis.

16. The tibial tray prosthesis of claim 15, wherein said first lateral surface comprises an anterior curvature and a posterior curvature, said anterior curvature having a radius of curvature r1 to said anterior-posterior diameter a in a ratio r1/a ranging from 0.35-0.65; the ratio r2/a of the curvature radius r2 of the trailing edge curved surface to the front-rear diameter a ranges from 0.4 to 0.6.

17. The tibial tray prosthesis of claim 16, wherein said first lateral surface further comprises a straight surface segment, said straight surface segment having two ends connected to said leading curved surface and said trailing curved surface, respectively, and a ratio e/a of a length e of said straight surface segment to said anterior-posterior diameter a is in the range of 0.09-0.12.

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