CN114521997A

CN114521997A - Tibial insert and knee prosthesis

Info

Publication number: CN114521997A
Application number: CN202210127945.4A
Authority: CN
Inventors: 徐学方; 王晓红; 毕征; 宋大勇; 董骧; 胡森元; 曲铁兵
Original assignee: Beijing Naton Medical Technology Holdings Co Ltd
Current assignee: Beijing Naton Medical Technology Holdings Co Ltd
Priority date: 2022-02-11
Filing date: 2022-02-11
Publication date: 2022-05-24

Abstract

The invention discloses a tibial gasket and a knee joint prosthesis, wherein the tibial gasket comprises: the inner side nest and the outer side nest, the rear end of inner side nest is equipped with inboard back lip, the rear end of outer side nest is equipped with outside back lip, the upper end of outside back lip has the cross-sectional area, the outside in cross-sectional area is not higher than the inboard in cross-sectional area, the front end in cross-sectional area is not higher than the rear end in cross-sectional area. The tibia liner is reasonable in structural design and good in using effect.

Description

Tibial insert and knee prosthesis

Technical Field

The invention relates to the technical field of medical instruments, in particular to a tibial gasket and a knee joint prosthesis.

Background

Knee replacement adopts an artificial knee prosthesis to replace diseased articular cartilage and menisci and retains normal articular ligaments and other tissues, so that the knee replacement has the advantages of small wound, quick recovery, reduced pain, more natural range of motion and the like, and is widely applied to knee treatment.

In the related art, due to the unreasonable structural design between the femoral prosthesis and the tibial gasket, when a human body is in a high-flexion condition, the posterior condyle part of the lateral condyle of the femoral prosthesis can be in contact with the posterior articular surface of the lateral articular surface of the tibial gasket and the posterior horn of the gasket, so that the rotation of the knee joint is limited, the stress of bone cement is easily increased, and the risk of loosening the prosthesis is increased.

Disclosure of Invention

The present invention is directed to solving, at least in part, one of the technical problems in the related art.

Therefore, the embodiment of the invention provides the tibial gasket which is reasonable in structural design and good in using effect.

The embodiment of the invention also provides a knee joint prosthesis.

The tibial insert of an embodiment of the present invention comprises: the inner side socket comprises an inner side socket and an outer side socket, wherein the rear end of the inner side socket is provided with an inner side rear lip, the rear end of the outer side socket is provided with an outer side rear lip, the upper end of the outer side rear lip is provided with a cross-sectional area, the outer side of the cross-sectional area is not higher than the inner side of the cross-sectional area, and the front end of the cross-sectional area is not higher than the rear end of the cross-sectional area.

According to the tibia liner disclosed by the embodiment of the invention, the outer side of the cross section area at the upper end of the outer side back lip is not higher than the inner side of the cross section area, and the front end of the cross section area is not higher than the rear end of the cross section area, so that the blocking effect of the outer side back lip on a femoral prosthesis is smaller, the femoral prosthesis can reach a larger external rotation angle, the tibia liner disclosed by the embodiment of the invention can reduce the interface stress of bone cement, the using effect of the tibia liner is better, and the reliability is higher.

In some embodiments, a dimension between an anterior end of the cross-sectional region and a posterior end of the cross-sectional region in a horizontal plane is L1, and a dimension between an anterior end of the tibial insert and a posterior end of the tibial insert is LAP, wherein 0.2 ≦ L1/LAP ≦ 0.4.

In some embodiments, the distance between the lateral side of the cross-sectional area and the median sagittal plane of the tibial insert is L2, the lateral socket is adapted to mate with a lateral condyle of a femoral prosthesis, and the distance between the motion trajectory line of the lowest point of the lateral condyle in the lateral socket and the median sagittal plane of the tibial insert is L3, wherein 0.6 ≦ L2/L3 ≦ 0.9.

In some embodiments, the height of the outboard rear lip is no greater than the height of the inboard rear lip.

In some embodiments, the height difference between the highest point of the cross-sectional area and the lowest point of the lateral fossa is H1, wherein H1 is greater than or equal to 0 and less than or equal to 3 mm.

In some embodiments, the surface of the cross-sectional area is a curved surface, and the peripheral profile of the cross-sectional area is substantially a sector.

In some embodiments, the tibial insert is a PS-type tibial insert or a CR-type tibial insert.

A knee joint prosthesis according to another embodiment of the present invention includes: a femoral prosthesis comprising a medial condyle and a lateral condyle; a tibial insert as in any preceding embodiment, the medial condyle mating with the medial socket and the lateral condyle mating with the lateral socket.

According to the knee joint prosthesis disclosed by the embodiment of the invention, the blocking effect of the outer back lip of the tibial gasket on the femoral prosthesis is smaller, so that the femoral prosthesis can reach a larger outward rotation angle, the interface stress of bone cement can be reduced, the using effect of the tibial gasket is better, the reliability is higher, and the risk of loosening the knee joint prosthesis is reduced.

Drawings

Fig. 1 is a top view of a tibial insert according to an embodiment of the present invention.

Fig. 2 is a side view of a tibial insert according to an embodiment of the present invention.

Fig. 3 is a side view of a tibial insert according to another embodiment of the present invention.

Fig. 4 is a sectional view of a knee joint prosthesis according to an embodiment of the present invention.

Fig. 5 is a schematic view of an uncorrupted section of a tibial insert according to an embodiment of the present invention.

Fig. 6 is a schematic view of a tibial insert having a cross-sectional area according to an embodiment of the present invention.

FIG. 7 is a graph comparing the degree of supination of a knee prosthesis of one embodiment of the present invention with an original knee.

FIG. 8 is a comparison of the supination angle of a knee prosthesis of another embodiment of the present invention with an original knee.

Reference numerals:

1. a tibial insert; 11. the medial fossa; 111. an inner rear lip; 12. the lateral fossa; 121. an outer rear lip; 1211. a cross-sectional area;

2. a femoral prosthesis; 21. a medial condyle; 22. the lateral condyle.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In order to better explain and explain the technical solution of the present invention, the directions and the like involved in the present invention are explained and explained in conjunction with the general description method in the art.

In the field of anatomical and medical devices, the directions and planes of the medial, lateral, anterior, posterior, distal, proximal, sagittal, coronal, transverse, and the like have specific meanings and are well known to those skilled in the art, and these terms refer to meanings recognized by those skilled in the art unless otherwise specified.

Generally, when describing a human body, a joint or a prosthesis, three sections are generally involved: sagittal, coronal, and transverse. The sagittal plane is a longitudinal section which divides the human body or the joint into a left part and a right part from the front to the back, wherein the sagittal plane passing through the middle of the human body is the middle sagittal plane which divides the human body into two parts which are equal to each other on the left and the right. The coronal plane is a longitudinal section dividing the human body or joints into two parts, the anterior and posterior, from the left and right, and is perpendicular to the sagittal plane. The cross section is a plane parallel to the ground plane and dividing the human body or the joint into an upper part and a lower part, and the cross section is vertical to the coronal plane and the sagittal plane.

It will be understood that when describing a knee joint or knee prosthesis, the sagittal, coronal and transverse planes are all intended to be the cut planes when a person is standing normally upright, with the knee joint having a knee flexion angle of 0 °. When the knee joint or the knee joint prosthesis is stretched and bent or the posture of the human body is adjusted, the tangent plane can be changed accordingly.

Generally, when describing a human body, a joint or a prosthesis, three different types of directions are involved: far and near, inside and outside, and front and back. Wherein, the far end refers to the end of the human body or the joint relatively far away from the trunk. Proximal refers to the end of the body or joint that is relatively close to the torso. The medial side refers to the side that is relatively close to the midsagittal plane of the human body. Lateral refers to the side of the body that is relatively far from the midsagittal plane of the body. The anterior end refers to the end on the sagittal plane that is relatively close to the abdomen. The posterior end refers to the end of the sagittal plane that is relatively close to the back.

A tibial insert and a knee joint prosthesis according to an embodiment of the present invention will be described with reference to fig. 1 to 8.

As shown in fig. 1 to 4, the tibial insert 1 according to the embodiment of the present invention includes a medial socket 11 and a lateral socket 12, a posterior end of the medial socket 11 is provided with a medial posterior lip 111, a posterior end of the lateral socket 12 is provided with a lateral posterior lip 121, an upper end of the lateral posterior lip 121 has a cross-sectional area 1211, a lateral side of the cross-sectional area 1211 is not higher than an inner side of the cross-sectional area 1211, and a front end of the cross-sectional area 1211 is not higher than a posterior end of the cross-sectional area 1211. It will be appreciated that the medial and

lateral sockets

11, 12 of the tibial insert 1 are adapted to cooperate with the medial and

lateral condyles

21, 22 of the femoral prosthesis 2, and that the femoral prosthesis 2 may rock or rotate anteriorly and posteriorly relative to the tibial insert 1.

If the prosthesis between the femur and the tibia is restricted in rotation during deep squatting, on the one hand the patient cannot recover the natural knee sensation, and on the other hand the bone cement interface is stressed more, thus increasing the risk of loosening of the prosthesis. Clinical studies have found that in total knee arthroplasty, prosthetic loosening is the most common cause of knee joint failure, with failure cases due to loosening accounting for as high as 25% -40%.

In the tibial insert 1 according to the embodiment of the present invention, the cross-sectional area 1211 is provided at the upper end of the lateral posterior lip 121, so that the height of the lateral posterior lip 121 can be reduced by the cross-sectional area 1211. In other words, the tibial gasket 1 of the embodiment of the present invention optimizes the external rotation angle of the femoral component 2 by providing the fracture surface area 1211, so that the knee joint component can reach a larger external rotation angle of the femur during high flexion while ensuring that the femoral component 2 is not dislocated, thereby reducing the interface stress of bone cement, reducing the risk of loosening the component, and improving the reliability of the component.

It will be appreciated that, as shown in fig. 1, when the knee prosthesis is moved medially about medial socket 11, the motion trajectory of lateral condyle 22 of femoral prosthesis 2 on lateral socket 12 of tibial insert 1 is approximately curved, and is more pronounced in the area closer to the posterior side of tibial insert 1, so that at larger external rotation angles, femoral prosthesis 2 is primarily in contact with lateral posterior lip 121 of tibial insert 1, and when the height of lateral posterior lip 121 of tibial insert 1 is reduced by providing cross-sectional area 1211, the blocking effect of lateral posterior lip 121 of tibial insert 1 on femoral prosthesis 2 is reduced, thereby facilitating femoral prosthesis 2 to reach a greater external rotation angle.

In addition, since the outer side of the cross-sectional area 1211 is not higher than the inner side of the cross-sectional area 1211, that is, the outer side of the cross-sectional area 1211 is lower than or equal to the inner side of the cross-sectional area 1211, and the front end of the cross-sectional area 1211 is lower than or equal to the rear end of the cross-sectional area 1211, the outer rear lip 121 has a small blocking effect on the femoral prosthesis 2, so that the femoral prosthesis 2 can reach a large outward rotation angle, and the tibial gasket 1 of the embodiment of the present invention can reduce the interface stress of bone cement, so that the tibial gasket 1 has the advantages of reasonable structural design, good use effect and high reliability. And the fracture surface 1211 with the structure has better wrapping performance on the femoral prosthesis 2 and is not easy to have the risk of dislocation.

In some embodiments, the height of the outboard rear lip 121 is no greater than the height of the inboard rear lip 111. In other words, the height of the outer rear lip 121 is equal to or lower than the height of the inner rear lip 111.

For example, the height of the lateral posterior lip 121 is equal to the height of the medial posterior lip 111 so that the tibial insert 1 of embodiments of the present invention can increase the degree of supination in high flexion of the femoral prosthesis without changing the rotational stability of the femoral prosthesis in low flexion.

For another example, the height of the lateral posterior lip 121 is less than the height of the medial posterior lip 111, such that the tibial insert 1 of embodiments of the present invention may provide greater increases in the degree of supination during high flexion of the prosthesis, while providing low flexion stability during normal knee motion.

Specifically, as shown in fig. 1, the surface of the cross-sectional area 1211 is a curved surface, and the outer peripheral profile of the cross-sectional area 1211 is substantially a sector, so as to facilitate the processing and manufacturing of the cross-sectional area 1211, and to make the structural design of the lateral posterior lip 121 more reasonable, thereby further improving the use effect of the tibial insert 1.

Alternatively, as shown in FIG. 1, in the horizontal plane, the dimension between the anterior end of the cross-sectional area 1211 and the posterior end of the cross-sectional area 1211 is L1, and the dimension between the anterior end of the tibial insert 1 and the posterior end of the tibial insert 1 is LAP, wherein 0.2 ≦ L1/LAP ≦ 0.4. The inventor of the present application found through experimental studies that when the dimension L1 between the front end of the fracture surface 1211 and the rear end of the fracture surface 1211 and the dimension LAP between the front end of the tibial insert 1 and the rear end of the tibial insert 1 satisfy the above ranges, the blocking effect of the lateral posterior lip 121 on the femoral prosthesis 2 can be further improved and reduced, the external rotation angle of the femoral prosthesis 2 can be improved while ensuring that the femoral prosthesis 2 does not dislocate, and when the L1/LAP satisfies the above ranges, the interface stress of the cement filled between the prosthesis and the human joint is small, and the reliability is high.

For example, L1/LAP may be 0.2, 0.3, 0.35, 0.4. The inventor of the present application finds through experimental studies that when L1/LAP is the above value, the external rotation angle of the femoral prosthesis 2 can be further increased, and the interface stress of the bone cement can be reduced.

Further, as shown in FIG. 1, the distance between the lateral side of the cross-sectional area 1211 (the left end of the cross-sectional area 1211) and the median sagittal plane of the tibial insert 1 is L2, the lateral socket 12 is adapted to mate with the lateral condyle 22 of the femoral prosthesis 2, and the distance between the trajectory of motion of the lowest point of the lateral condyle 22 in the lateral socket 12 and the median sagittal plane P of the tibial insert 1 is L3, wherein 0.6L 2/L3 0.9. It will be appreciated that as the lateral condyle 22 oscillates anteriorly and posteriorly within the lateral fossa 12, the lowest point of the lateral condyle 22 forms a motion trajectory line within the lateral fossa 12 that is generally parallel to the median sagittal plane, the distance between the motion trajectory line and the median sagittal plane of the tibial insert 1 being L3.

The inventor of the present application found through experimental studies that when L2/L3 satisfies the above range, the blocking effect of the lateral posterior lip 121 on the femoral prosthesis 2 can be further improved, the external rotation angle of the femoral prosthesis 2 can be improved while ensuring that the femoral prosthesis 2 does not dislocate, and when L2/L3 satisfies the above range, the interface stress of the bone cement filled between the prosthesis and the human body joint is small, and the reliability is high.

For example, L2/L3 may be 0.6, 0.65, 0.7, 0.8, 0.9. The inventor of the present application finds through experimental studies that when L2/L3 is the above value, the external rotation angle of the femoral prosthesis 2 can be further increased, and the interface stress of the bone cement can be reduced.

Optionally, as shown in FIG. 1 and FIG. 2, the height difference between the highest point of the cross-sectional area 1211 and the lowest point of the lateral fossa 12 is H1, wherein H1 is greater than or equal to 0 mm and less than or equal to 3 mm. For example, H1 may be 0, 1mm, 2mm, 3 mm. Through experimental research, the inventor of the present application finds that when H1 satisfies the above range, the outward rotation angle of the femoral component 2 can be further increased, the interface stress of the bone cement can be reduced, and the structural design of the tibial gasket 1 is more reasonable and the using effect is better.

Specifically, as shown in fig. 2 and 3, the tibial insert 1 is a PS-type tibial insert or a CR-type tibial insert, for example, as shown in fig. 5 and 6, which is a comparison of the PS-type tibial insert before the section 1211 and after the section 1211 is provided. As shown in fig. 1, a top view of a cross-sectional area 1211 is provided for a CR-type tibial insert.

Specifically, the inventors conducted comparative experiments using either PS-type tibial inserts or CR-type tibial inserts, respectively, as follows.

As shown in fig. 7, the inventor provides a section area 1211 on a PS-type tibial insert and manufactures two different types of section areas 1211, namely scheme 1 and scheme 2 in fig. 7, specifically, the prosthesis size of the scheme 1 is the same as that of the scheme 2, and the value of L2/L3 of the section area 1211 of the scheme 1 is smaller than that of L2/L3 of the section area 1211 of the scheme 2. Then, a comparison experiment is performed between the scheme 1 and the scheme 2 and the original knee joint, and the inventor of the application finds that the knee joint prosthesis has a larger external rotation angle by arranging the section area 1211 with the structure on the PS-type tibial pad, so that the knee joint prosthesis has a better use effect.

As shown in fig. 8, the inventor provides a section area 1211 on a CR-type tibial insert, and manufactures two different types of section areas 1211, namely scheme 1 and scheme 2 in fig. 8, specifically, the prosthesis size of the scheme 1 is the same as that of the scheme 2, and the value of L2/L3 of the section area 1211 of the scheme 1 is smaller than that of L2/L3 of the section area 1211 of the scheme 2. Then, a comparison experiment is performed between the scheme 1 and the scheme 2 and the original knee joint, and the inventor of the application finds that the knee joint prosthesis has a larger external rotation angle by arranging the section area 1211 with the structure on the PS-type tibial pad, so that the knee joint prosthesis has a better use effect.

The inventors therefore conclude that the tibial insert 1 may be a posterior stabilized tibial insert prosthesis or a posterior cruciate ligament replacement tibial insert prosthesis, and that the present application is not limited as to the type of tibial insert.

As shown in fig. 4, a knee joint prosthesis according to another embodiment of the present invention includes: the femoral component 2 and the tibial insert 1, the femoral component 2 includes a medial condyle 21 and a lateral condyle 22, the tibial insert 1 is the tibial insert 1 of the above-mentioned embodiment of the present invention, the medial condyle 21 is matched with the medial socket 11, and the lateral condyle 22 is matched with the lateral socket 12.

The outer back lip 121 of the tibial gasket 1 of the knee joint prosthesis according to the embodiment of the invention has a small blocking effect on the femoral prosthesis 2, so that the femoral prosthesis 2 can reach a large outward rotation angle, and the knee joint prosthesis according to the embodiment of the invention can reduce the interface stress of bone cement, so that the tibial gasket 1 has a good use effect, the risk of loosening of the knee joint prosthesis is reduced, and the reliability of the implanted knee joint prosthesis is high.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "second", "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the second feature "on" or "under" the second feature may be directly contacting the second feature or indirectly contacting the second feature through intervening media. Also, a second feature "on," "above," and "over" a second feature may be directly or obliquely above the second feature, or simply indicate that the second feature is at a higher level than the second feature. A second feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the second feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A tibial gasket is characterized by comprising an inner socket and an outer socket, wherein an inner back lip is arranged at the back end of the inner socket, an outer back lip is arranged at the back end of the outer socket, a sectional area is arranged at the upper end of the outer back lip, the outer side of the sectional area is not higher than the inner side of the sectional area, and the front end of the sectional area is not higher than the back end of the sectional area.

2. The tibial insert of claim 1, wherein a dimension between the anterior end of the cross-sectional area and the posterior end of the cross-sectional area is L1 and a dimension between the anterior end of the tibial insert and the posterior end of the tibial insert is LAP, wherein L1/LAP ≦ 0.4 at 0.2 ≦ L1/LAP, in the horizontal plane.

3. The tibial insert of claim 1 wherein the distance between the lateral side of said cross-sectional area and the median sagittal plane of said tibial insert is L2, said lateral socket is adapted to mate with the lateral condyle of a femoral prosthesis, and the distance between the trajectory of motion of the lowest point of said lateral condyle within said lateral socket and the median sagittal plane of said tibial insert is L3, wherein 0.6 ≦ L2/L3 ≦ 0.9.

4. The tibial insert of claim 1, wherein said lateral posterior lip has a height no greater than a height of said medial posterior lip.

5. The tibial insert of claim 1, wherein the difference in height between the highest point of said cross-sectional area and the lowest point of said lateral socket is H1, wherein 0 ≦ H1 ≦ 3 mm.

6. The tibial insert of claim 1 wherein said surface of said cross-sectional area is curved and said cross-sectional area has a generally scalloped peripheral profile.

7. The tibial insert of any of claims 1-6, wherein said tibial insert is a PS-type tibial insert or a CR-type tibial insert.

8. A knee joint prosthesis, comprising:

a femoral prosthesis comprising a medial condyle and a lateral condyle;

a tibial insert as claimed in any of claims 1 to 7, the medial condyle cooperating with the medial socket and the lateral condyle cooperating with the lateral socket.