Disclosure of Invention
Based on this, it is necessary to provide a tibial insert that addresses the problem of how to improve the stability of the knee joint after total knee arthroplasty.
The present application provides a tibial insert comprising:
A medial articular surface, wherein a cross section line formed by intersecting the medial articular surface and a first sagittal plane comprises a first circular arc, a first straight line segment and a second circular arc which are sequentially connected, the curvature radius of the first circular arc is larger than or equal to that of the second circular arc, and
The outer joint surface, a cross section line formed by intersecting the outer joint surface and the second sagittal plane comprises a fourth circular arc, a second straight line segment and a fifth circular arc which are sequentially connected, and the curvature radius of the fourth circular arc is larger than or equal to that of the fifth circular arc.
The technical scheme of the application is further described as follows:
In one embodiment, the cross-sectional line formed by the intersection of the medial articular surface and the first coronal surface comprises a third circular arc, wherein the radius of curvature of the third circular arc is equal to the radius of curvature of the first circular arc, and/or the cross-sectional line formed by the intersection of the lateral articular surface and the second coronal surface comprises a sixth circular arc, and the radius of curvature of the sixth circular arc is equal to the radius of curvature of the fourth circular arc.
In one embodiment, the length of the first straight line segment ranges from 0.1mm to 3mm, and/or the length of the second straight line segment ranges from 9mm to 14mm.
In one embodiment, the medial edge to lateral edge distance of the tibial insert is a first distance, the tibial insert having a central sagittal plane defining the medial articular surface and the lateral articular surface;
The distance from the first straight line segment to the central sagittal plane is a second distance, the ratio of the second distance to the first distance is in the range of 0.25-0.35, and/or the distance from the second straight line segment to the central sagittal plane is a third distance, and the ratio of the third distance to the first distance is in the range of 0.25-0.35.
In one embodiment, the distance from the front edge to the rear edge of the medial articular surface is a fourth distance, the distance from the midpoint of the first straight line segment to the rear edge of the medial articular surface is a fifth distance, the ratio of the fifth distance to the fourth distance is in the range of 0.3-0.5, and/or the distance from the front edge to the rear edge of the lateral articular surface is a sixth distance, the distance from the midpoint of the second straight line segment to the rear edge of the lateral articular surface is a seventh distance, and the ratio of the seventh distance to the sixth distance is in the range of 0.3-0.5.
In one embodiment, the first arc has a vertical distance from the end point of the anterior edge of the medial articular surface to the first line segment of 6mm-13mm, and/or the second arc has a vertical distance from the end point of the posterior edge of the medial articular surface to the first line segment of 0.2mm-4mm.
In one embodiment, the perpendicular distance from the end point of the fourth arc at the front side edge of the lateral articular surface to the second straight line segment is 3mm-7mm, and/or the perpendicular distance from the end point of the fifth arc at the rear side edge of the lateral articular surface to the second straight line segment is 0.2mm-3mm.
In one embodiment, the tibial insert further comprises a convex surface connecting the medial articular surface and the lateral articular surface, a cross-sectional line formed by the convex surface and a third coronal surface comprises a seventh arc, a cross-sectional line formed by the medial articular surface and the third coronal surface comprises an eighth arc, a cross-sectional line formed by the lateral articular surface and the third coronal surface comprises a ninth arc, the seventh arc is tangent to the eighth arc, and the seventh arc is tangent to the ninth arc.
In one embodiment, the radius of curvature of the seventh arc ranges from 35mm to 50mm.
In one embodiment, the medial articular surface has a first bearing center line in cross section, wherein the first bearing center line comprises a third straight line segment, a tenth circular arc and a fourth straight line segment which are sequentially connected, and the tenth circular arc is tangent to the third straight line segment and the fourth straight line segment respectively.
In one embodiment, the medial edge to lateral edge distance of the tibial insert is a first distance, the tibial insert has a central sagittal plane defining the medial articular surface and the lateral articular surface, the anterior edge to posterior edge distance of the medial articular surface is a fourth distance, the intersection of the extension of the third straight line segment and the extension of the fourth straight line segment is a first intersection,
The distance from the first intersection point to the rear side edge of the medial articular surface is an eighth distance, the ratio of the eighth distance to the fourth distance ranges from 0.35 to 0.45, and/or the distance from the first intersection point to the central sagittal surface is a ninth distance, and the ratio of the ninth distance to the first distance ranges from 0.25 to 0.3.
In one embodiment, the tibial insert has a central sagittal plane defining the medial articular plane and the lateral articular plane, and the fourth straight line is parallel to the central sagittal plane.
In one embodiment, the tibial insert has a central sagittal plane defining the medial and lateral articular planes, and the third straight line segment is at an angle in the range of 20 ° -25 ° from the central sagittal plane.
In one embodiment, the lateral articular surface has a second bearing center line in cross section, wherein the second bearing center line comprises a fifth straight line segment and an eleventh circular arc which are sequentially connected, and the eleventh circular arc is tangent to the fifth straight line segment.
In one embodiment, the medial edge to lateral edge distance of the tibial insert is a first distance, the tibial insert has a central sagittal plane defining the medial and lateral articular surfaces, and the anterior to posterior edge distance of the lateral articular surface is a sixth distance;
The third tangent point is a tenth distance from the posterior edge of the lateral articular surface, the ratio of the tenth distance to the sixth distance being in the range of 0.35-0.45, and/or the third tangent point is an eleventh distance from the central sagittal plane, the ratio of the eleventh distance to the first distance being in the range of 0.25-0.3.
In one embodiment, the eleventh arc has a radius of curvature in the range of 35mm to 50mm.
In one embodiment, the tibial insert has a central sagittal plane defining the medial and lateral articular planes, and the fifth straight line segment is at an angle in the range of 10 ° -12 ° from the central sagittal plane.
The tibial insert improves the rotational stability of the knee joint prosthesis by designing the medial articular surface and the lateral articular surface in a ball-and-socket shape. In addition, the part intersection lines of the medial articular surface and the lateral articular surface and the sagittal surface are designed in a straight line, so that the installation inclusion degree of the knee joint prosthesis in the operation is increased.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application.
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view of the tibial insert of an embodiment;
FIG. 2 is a top view of a tibial insert of an embodiment;
FIG. 3 is a cross-sectional view of the tibial insert shown in FIG. 2, taken at section A-A;
FIG. 4 is a cross-sectional view of the tibial insert shown in FIG. 2, taken at section B-B;
FIG. 5 is a second top view of a tibial insert of an embodiment;
FIG. 6 is a cross-sectional view of the tibial insert shown in FIG. 5, taken at section D-D;
FIG. 7 is a cross-sectional view of the tibial insert shown in FIG. 5, taken at section C-C;
FIG. 8 is a top view III of a tibial insert of an embodiment;
FIG. 9 is a cross-sectional view of the tibial insert shown in FIG. 8, taken at section E-E;
FIG. 10 is a top view of a tibial insert of an embodiment;
FIG. 11 is a schematic view of the structure of an embodiment of a femoral condyle prosthesis.
Reference numerals illustrate:
10. Tibial bearing, 11, medial articular surface, L111, first distance, L112, second distance, L113, fourth distance, L114, fifth distance, L115, first straight line segment, L116, eighth distance, L117, ninth distance, R111, first arc, R112, second arc, R113, third arc, R114, tenth arc, 12, lateral articular surface, L122, third distance, L123, sixth distance, L124, seventh distance, L125, second straight line segment, L127, eleventh distance, L128, tenth distance, R121, fourth arc, R122, fifth arc, R123, sixth arc, R124, eleventh arc, 13, central sagittal plane, 14, convex surface, R141, seventh arc, 20, tibial prosthesis, 21, AP line, 22, medial condyle surface, 23, lateral articular surface.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.
In order to better explain the technical scheme related to the invention, the azimuth nouns related to each embodiment are explained first.
Sagittal plane, which is a section formed by longitudinally cutting a human body or a joint into a left part and a right part;
coronal plane, which is a section of human body or joint divided into front and back parts, the section is perpendicular to sagittal plane;
a cross section, which is to divide a human body or a joint into a section with an upper part and a lower part, wherein the section is perpendicular to a coronal plane and a sagittal plane;
The far end is one end of the human body or the joint relatively far from the head;
A proximal end, which is one end of the human body or joint relatively close to the head;
The inner side is relatively close to the sagittal plane of the human body;
Outside, relatively deviate from the sagittal plane of human body;
anterior side, the side near the chest on the sagittal plane;
The posterior side is the side near the back on the sagittal plane;
AP direction, the direction from anterior to posterior in the sagittal plane;
PA direction, the direction from posterior to anterior in the sagittal plane;
ML direction, the direction from inside to outside on the coronal plane;
LM direction-direction from outside to inside on the coronal plane.
Specifically, referring to fig. 1, one embodiment of the present application provides a tibial insert 10, the tibial insert 10 being adapted to be secured to a proximal tibia end on which an osteotomy has been completed or to a tibial tray prosthesis. Further, the tibia pad 10 is divided into a left leg tibia pad 10 applied to the left leg and a right leg tibia pad 10 applied to the right leg. Wherein the left and right leg tibial inserts 10, 10 are mirror symmetrical about the sagittal plane. In order to make the above objects, features and advantages of the present application more comprehensible, a left leg tibial insert 10 suitable for use with a left leg will be described in detail. Specifically, the tibial insert 10 of one embodiment includes a medial articular surface 11 and a lateral articular surface 12. Wherein medial articular surface 11 is used to replace the tibial medial meniscus and lateral articular surface 12 is used to replace the tibial lateral meniscus.
Specifically, referring to fig. 2-4, the cross-sectional line formed by the intersection of the medial articular surface 11 and the first sagittal plane includes a first circular arc R111, a first straight line segment L115, and a second circular arc R112 that are sequentially connected from the anterior side to the posterior side. The radius of curvature of the first circular arc R111 is greater than or equal to the radius of curvature of the second circular arc R112, and preferably the radius of curvature of the first circular arc R111 is equal to the radius of curvature of the second circular arc R112. Further, a cross-sectional line formed by the intersection of the medial articular surface 11 and the first coronal surface includes a third circular arc R113, and a radius of curvature of the third circular arc R113 is equal to a radius of curvature of the first circular arc R111.
The tibial insert 10 is configured such that the intersection line of the medial articular surface 11 and the first sagittal plane is configured as a first arc R111, a first straight line segment L115, and a second arc R112, which are sequentially connected, the intersection line of the medial articular surface 11 and the first coronal plane is configured as a third arc R113, and such that the radius of curvature of the first arc R111 is greater than or equal to the radius of curvature of the second arc R112, and such that the radius of curvature of the third arc R113 is equal to the radius of curvature of the first arc R111, thereby ensuring that the medial articular surface 11 forms a ball-and-socket shape, and further improving the rotational stability of the knee joint prosthesis. The partial intersection of the medial articular surface 11 with the sagittal plane is designed with a first straight line segment L115, which increases the intraoperative installation envelope of the knee prosthesis.
Specifically, the first sagittal plane is the section A-A taken along the line A-A in FIG. 2, with the cut-away location of the section A-A corresponding to the extent of the contact path during mating of the medial articular surface 11 with the femoral condyle. Specifically, tibial insert 10 has a central sagittal plane 13 defining medial articular surface 11 and lateral articular surface 12, wherein central sagittal plane 13 refers to the sagittal plane passing through the medial-lateral centerline of tibial insert 10, and the medial-lateral centerline of tibial insert 10 refers to a line bisecting tibial insert 10 into inner and outer portions, where "bisecting" refers to bisecting the lateral length of tibial insert 10. The medial edge to lateral edge distance of tibial insert 10 is denoted as first distance L111 and the first sagittal plane distance to the central sagittal plane 13 of tibial insert 10 (i.e., the first straight line segment L115 to the central sagittal plane 13) is denoted as second distance L112. The ratio of the second distance L112 to the first distance L111 ranges from 0.25 to 0.35.
With continued reference to FIG. 2, the first coronal plane is a cross-section B-B, and preferably passes through a midpoint a of the first straight segment L115. Specifically, the distance from the anterior edge of the medial articular surface 11 to the posterior edge is a fourth distance L113, and the distance from the midpoint a of the first straight line segment L115 to the posterior edge of the medial articular surface 11 (i.e., the distance from the first coronal plane to the posterior edge of the medial articular surface 11) is a fifth distance L114, wherein the ratio of the fifth distance L114 to the fourth distance L113 is in the range of 0.3-0.5, preferably 0.35-0.45.
The midpoint a of the first straight line segment L115 is the center position of the medial bearing area of the natural knee joint extension position, the midpoint position of the first straight line segment L115 is defined by the ratio range of the second distance L112 to the first distance L111 and the ratio range of the fifth distance L114 to the fourth distance L113, and then the contact position of the extension position femoral component and the tibial liner 10 prosthesis is defined, so that the postoperative knee joint extension and the flexion gap are prevented from being excessively loosened and tightened.
Further, the length of the first straight line segment L115 ranges from 0.1mm to 3mm, preferably from 0.5mm to 1.5mm. Such a design can enhance the fit containment of medial articular surface 11 during knee surgery and provide a natural knee joint movement area.
Referring to fig. 3, the perpendicular distance H111 from the end point of the anterior edge of the medial articular surface 11 (i.e., the intersection of the anterior edge and the first sagittal plane) to the first straight line segment L115 (i.e., the anterior lip height of the medial articular surface 11) is 6mm-13mm, preferably 8mm-12mm, thereby ensuring stability of the medial articular surface 11 in the PA direction while avoiding patella impingement with the anterior edge of the tibial insert 10 during high flexion of the knee joint. And/or the perpendicular distance H112 from the end point of the posterior edge of the medial articular surface 11 (i.e., the intersection of the posterior edge and the first sagittal plane) to the first straight line segment L115 (i.e., the posterior lip height of the medial articular surface 11) is 0.2mm-4mm, preferably 0.5mm-3mm, thereby ensuring stability of the medial articular surface 11 in the AP direction and solving the problem of difficulty in implanting the tibial insert 10 into the human body during knee replacement.
In particular, referring to FIGS. 5-7, the cross-sectional line of the lateral articular surface 12 intersecting the second sagittal plane includes a fourth circular arc R121, a second straight line segment L125, and a fifth circular arc R122 that are sequentially connected from anterior to posterior. The radius of curvature of the fourth arc R121 is greater than or equal to the radius of curvature of the fifth arc R122, and preferably, the radius of curvature of the fourth arc R121 is equal to the radius of curvature of the fifth arc R122. Further, a cross-sectional line formed by the intersection of the lateral articular surface 12 and the second coronal surface includes a sixth arc R123, and the radius of curvature of the sixth arc R123 is equal to the radius of curvature of the fourth arc R121.
The tibial insert 10 further improves the rotational stability of the knee prosthesis by configuring the intersection line of the lateral articular surface 12 and the second sagittal plane as the fourth circular arc R121, the second straight line segment L125, and the fifth circular arc R122, which are sequentially connected, and configuring the intersection line of the lateral articular surface 12 and the second coronal plane as the sixth circular arc R123, such that the radius of curvature of the fourth circular arc R121 is greater than or equal to the radius of curvature of the fifth circular arc R122, and simultaneously by making the radius of curvature of the sixth circular arc R123 equal to the radius of curvature of the fourth circular arc R121, the formation of the lateral articular surface 12 into a ball-and-socket shape is ensured. In addition, the partial intersection line of the lateral articular surface 12 and the sagittal plane adopts the design of the second straight line segment L125, so that the installation inclusion degree of the knee joint prosthesis in operation is increased.
Specifically, the second sagittal plane is the section D-D of FIG. 5, with the cut-away position of section D-D corresponding to the extent of the contact path during mating of the lateral articular surface 12 with the femoral condyle. Specifically, the distance from the second sagittal plane to the central sagittal plane 13 of the tibial insert 10 (i.e., the distance from the second straight line segment L125 to the central sagittal plane 13) is noted as a third distance L122. The ratio of the third distance L122 to the first distance L111 ranges from 0.25 to 0.35.
With continued reference to FIG. 5, the second coronal plane is a cross-section C-C, and preferably passes through a midpoint b of the second straight segment L125. Specifically, the distance from the anterior edge of the lateral articular surface 12 to the posterior edge is a sixth distance L123, and the distance from the midpoint b of the second straight line segment L125 to the posterior edge of the lateral articular surface 12 (i.e., the distance from the second coronal surface to the posterior edge of the lateral articular surface 12) is a seventh distance L124, wherein the ratio of the seventh distance L124 to the sixth distance L123 is in the range of 0.3-0.5, preferably 0.35-0.45. Preferably, the second coronal plane coincides with the first coronal plane.
The midpoint b of the second straight line segment L125 is the center position of the bearing area on the inner side of the natural knee joint straightening position, and the position of the midpoint b of the second straight line segment L125 is limited by the ratio range of the third distance L122 to the first distance L111 and the ratio range of the seventh distance L124 to the sixth distance L123, so that the contact position of the straightening femoral component and the tibial liner 10 prosthesis is limited, and the postoperative knee joint straightening and the overloosening and the overtightening of the buckling gap are avoided.
Further, the length of the second straight line segment L125 is in the range of 9mm to 14mm, preferably 10mm to 12mm. Such a design can enhance the fit containment of lateral articular surface 12 during knee surgery and provide a natural knee joint movement area.
Referring to fig. 6, the perpendicular distance H121 from the end point of the anterior edge of the lateral articular surface 12 (i.e., the intersection of the anterior edge and the second sagittal plane) to the second straight line segment L125 (i.e., the anterior lip height of the lateral articular surface 12) is 3mm-7mm, preferably 4mm-6mm, to ensure stability of the lateral articular surface 12 in the PA direction while avoiding patella impingement with the anterior edge of the tibial insert 10 during high flexion of the knee joint. And/or the perpendicular distance H122 from the end point of the fifth arc R122 at the posterior edge of the lateral articular surface 12 (i.e., the intersection of the posterior edge and the second sagittal plane) to the second straight-line segment L125 (i.e., the posterior lip height of the lateral articular surface 12) is 0.2mm-3mm, preferably 0.5mm-2.5mm, thereby ensuring stability of the lateral articular surface 12 in the AP direction and solving the problem of difficult implantation of the tibial insert 10 into the human body during knee replacement.
Referring to fig. 8-9, tibial insert 10 further includes a convex surface 14 connecting medial articular surface 11 and lateral articular surface 12, a cross-sectional line formed by convex surface 14 and the third coronal surface includes a seventh arc R141, a cross-sectional line formed by medial articular surface 11 and the third coronal surface includes an eighth arc, a cross-sectional line formed by lateral articular surface 12 and the third coronal surface includes a ninth arc, seventh arc R141 is tangent to the eighth arc, and seventh arc R141 is tangent to the ninth arc. Preferably, referring to fig. 9, the third coronal plane coincides with the second coronal plane and the first coronal plane, and the eighth arc is the third arc R113, and the ninth arc is the sixth arc R123.
Further, the radius of curvature of the seventh arc R141 ranges from 35mm to 50mm. If the radius of curvature of the seventh arc R141 is too large, the stability of the tibial insert 10 in the ML direction and the LM direction is poor, and if the radius of curvature of the seventh arc R141 is too small, the tibial insert 10 is difficult to implant into the human body. By setting the radius of curvature of the seventh arc R141 to 35mm-50mm, not only is stability of the tibial insert 10 in the ML direction and the LM direction ensured, but also a doctor can implant the tibial insert 10 into a human body conveniently.
Further, natural knee motion exists with rotational motion centered on the medial meniscus and the medial femoral condyle midline is not parallel to the AP line 21 and the lateral femoral condyle midline is not parallel to the AP line 21. Therefore, the medial articular surface 11 and the lateral articular surface 12 of the tibial insert 10 need to be designed to account for not only how the femoral condyles are guided to rotate, but also the design of the swing head of the tibial insert 10 at the anterior end of the articular surface so as to provide better fit and contact area of the articular surface of the tibial insert 10 in the straightened and overstretched positions.
Referring to fig. 10, medial articular surface 11 has a first load bearing midline in cross-section. Specifically, the first load bearing midline refers to the collection of points at which the femoral condyle prosthesis contacts the medial articular surface 11 of the tibial insert 10 during flexion, i.e., the locus of movement of the femoral condyle prosthesis on the medial articular surface 11 of the tibial insert 10 during knee flexion. Further, the point on the first load bearing midline is the most concave (lowest) point of the medial articular surface 11 on the coronal plane. Specifically, in the present embodiment, the first load-bearing center line includes a third straight line segment FM, a tenth circular arc R114, and a fourth straight line segment NG that are sequentially connected. The tenth circular arc R114 is tangent to the third straight line segment FM and the fourth straight line segment NG, respectively.
Further, an intersection point of the extension line of the third straight line segment FM and the extension line of the fourth straight line segment NG is a first intersection point P, a distance from the first intersection point P to the rear side edge of the medial articular surface 11 is an eighth distance L116, a ratio of the eighth distance L116 to the fourth distance L113 is in a range of 0.35-0.45, and/or a distance from the first intersection point P to the central sagittal plane 13 is noted as a ninth distance L117, and a ratio of the ninth distance L117 to the first distance L111 is in a range of 0.25-0.3.
Further, the fourth straight segment NG is parallel to the central sagittal plane 13. Further, the included angle α111 between the third straight line segment FM and the central sagittal plane 13 is 20 ° -25 °, which can make the femoral condyle prosthesis and the tibial insert 10 obtain better assemblability and contact area in the extending-to-straightening process, make the tibial insert 10 uniformly stressed, and improve the service life of tibia.
Referring to fig. 10, the lateral articular surface 12 has a second load-bearing midline in cross-section, which, as such, refers to the collection of points at which the femoral condyle prosthesis contacts the lateral articular surface 12 of the tibial insert 10 during flexion, i.e., the locus of movement of the femoral condyle prosthesis on the lateral articular surface 12 of the tibial insert 10 during knee flexion. Further, the point on the first load bearing midline is the most concave (lowest) point of the medial articular surface 11 on the coronal plane. Specifically, in this embodiment, the second load-bearing center line includes a fifth straight line segment CD and an eleventh circular arc R124 connected in sequence, where the eleventh circular arc R124 is tangent to the fifth straight line segment CD.
Further, the tangential point of the eleventh arc R124 and the fifth straight line segment CD is denoted as a third tangential point D, and the distance from the third tangential point D to the rear edge of the lateral articular surface 12 is a tenth distance L128, and the ratio of the tenth distance L128 to the sixth distance L123 ranges from 0.35 to 0.45. And/or the distance from the third tangent point D to the central sagittal plane 13 is an eleventh distance L127, and the ratio of the eleventh distance L127 to the first distance L111 is 0.25-0.3. Further, the range of the curvature radius of the eleventh arc R124 is 35mm-50mm, the range of the included angle alpha 121 between the fifth straight line segment CD and the central sagittal plane 13 is 10 degrees-12 degrees, and by adopting the design, the femoral condyle prosthesis and the tibial liner 10 can obtain better assembly and contact area in the extending process from overstretching to straightening, the tibial liner 10 is uniformly stressed, and the service life of tibia is prolonged.
Further, to illustrate in greater detail the anterior-side swing design of the tibial insert 10, a femoral condyle prosthesis is introduced herein to improve the fit and contact area of the knee prosthesis in the straightened and overstretched positions. Femoral condyle prostheses are used to secure to a distal femur ready for surgery to replace the articular surface of the distal femur. Referring to fig. 11, the femoral condyle prosthesis includes a medial condyle articular surface 22 and a lateral condyle articular surface 23. The medial condyle articular surface 22 has a spherical radius SR22, and the spherical radius SR22 has a value 0.5mm-1mm smaller than the radius of curvature of the third arc R113. The spherical radius of the lateral condyle articular surface 23 is SR23, and the value of the spherical radius SR23 is 0.5mm-1mm smaller than the curvature radius of the sixth arc R123. The medial condylar articular surface 22 swings at the anterior end by an amount α22, α22 having an equal value to α111. The lateral condyle articular surface 23 swings at the anterior end by α23, and the value of α23 is equal to the value of α121. By "swing" is meant that the anterior load bearing midline of the femoral condyle or the load bearing midline of the tibial insert 10 prosthesis is at an angle to the sagittal plane.
Through the design of the included angle between the third straight line segment and the central sagittal plane 13 and the included angle between the fifth straight line segment CD and the central sagittal plane 13, the femoral condyle prosthesis and the tibial liner 10 can obtain good assembly and contact area in the extending-to-straightening process, so that the tibial liner 10 is uniformly stressed, and the service life of the tibial liner 10 is prolonged.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by 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", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, 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 defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements 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 the like are used herein for illustrative purposes only and are not meant to be the only embodiment.