초록 ▼

A mobile tibial assembly includes a tibial tray and a tibial insert. The tibial tray includes a track that is defined in an upper surface, and the track has a bottom wall that is flat in the medial-lateral direction and convex in the anterior-posterior direction. The tibial insert includes a bottom

A mobile tibial assembly includes a tibial tray and a tibial insert. The tibial tray includes a track that is defined in an upper surface, and the track has a bottom wall that is flat in the medial-lateral direction and convex in the anterior-posterior direction. The tibial insert includes a bottom bearing surface configured to contact the upper surface of the tibial tray and a stem including a circular neck connected to the bottom bearing surface. The bottom bearing surface has a surface area that is less than the cross-sectional area of the circular neck. The convex upper surface of the tibial tray contacts the concave bottom bearing surface of the tibial insert and the tibial insert is freely rotatable about a central axis defined by the stem as the tibial insert is moved along the track relative to the tibial tray in the generally anterior-posterior direction.

대표청구항 ▼

1. A mobile tibial assembly comprising: a tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia, the tibial tray having (i) an upper surface, (ii) a bottom surface, the bottom surface being configured to contact a portion of the surgically-prepared surf

1. A mobile tibial assembly comprising: a tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia, the tibial tray having (i) an upper surface, (ii) a bottom surface, the bottom surface being configured to contact a portion of the surgically-prepared surface of the tibia when coupled thereto, and (iii) a track defined in the upper surface having a bottom wall that is flat in the medial-lateral direction and convex in the anterior-posterior direction; anda tibial insert having an (i) upper bearing surface and (ii) a bottom bearing surface configured to contact the upper surface of the tibial tray when the tibial insert is coupled to the tibial tray, the bottom bearing surface having a surface area, and (iii) a stem including a circular neck connected to the bottom bearing surface and a circular flange extending from a distal end of the circular neck, the circular neck having a first diameter and a cross-sectional area that is less than the surface area of the bottom bearing surface, the circular flange having a second diameter greater than the first diameter of the circular neck, the stem being received by the track of the tibial tray,wherein (i) the tibial insert is movable along the track relative to the tibial tray, (ii) the upper surface of the tibial tray is convex and the bottom bearing surface of the tibial insert is concave such that the convex upper surface of the tibial tray contacts the concave bottom bearing surface of the tibial insert as the tibial insert is moved along the track relative to the tibial tray in a generally anterior-posterior direction, and (iii) the tibial insert is freely rotatable about a central axis defined by the stem as the tibial insert is moved along the track relative to the tibial tray in the generally anterior-posterior direction. 2. The mobile tibial assembly of claim 1, wherein the bottom surface of the tibial tray comprises a first planar surface and a second planar surface, wherein the first planar surface is oblique relative to the second planar surface. 3. The mobile tibial assembly of claim 2, wherein the bottom surface of the tibial tray comprises a third planar surface oblique relative to the first and the second planar surfaces. 4. The mobile tibial assembly of claim 1, wherein the track of the tibial tray is defined by a first side wall, a second side wall, a first lip extending from the first side wall a first distance over a portion of the bottom wall, and a second lip extending from the second wall a second distance over a portion of the bottom wall, the second distance being greater than the first distance, and the first and second lips defining an opening therebetween. 5. The mobile tibial assembly of claim 4, wherein the circular flange has: (i) a bottom surface configured to contact the bottom wall when the stem is received thereby, and(ii) a top surface configured to contact a bottom surface of at least one of the first lip and the second lip of the track of the tibial tray when the stem is received thereby. 6. A tibial assembly comprising: a tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia, the tibial tray having (i) an upper surface, (ii) a bottom surface configured to contact a portion of the surgically-prepared surface of the tibia when coupled thereto and comprising an anterior planar surface extending from an anterior side of the tibial tray to a posterior end and a posterior planar surface extending from the posterior end of the anterior planar surface to a posterior side of the tibial tray, the posterior planar surface being angled downward such that the posterior planar surface is oblique to the anterior planar surface and the posterior side of the tibial tray is inferior to the anterior side of the tibial tray, and (iii) a track defined in the upper surface having a bottom wall that is flat in the medial-lateral direction and convex in the anterior-posterior direction; anda tibial insert having an (i) upper bearing surface and (ii) a bottom bearing surface configured to contact the upper surface of the tibial tray when the tibial insert is coupled to the tibial tray, the bottom bearing surface having a surface area, and (iii) a stem including a circular neck connected to the bottom bearing surface and a circular flange extending from a distal end of the circular neck, the circular neck having a first diameter and a cross-sectional area that is less than the surface area of the bottom bearing surface, the circular flange having a second diameter greater than the first diameter of the circular neck, the stem being received by the track of the tibial tray,wherein (i) the tibial insert is movable along the track relative to the tibial tray, (ii) the upper surface of the tibial tray is convex and the bottom bearing surface of the tibial insert is concave such that the convex upper surface of the tibial tray contacts the concave bottom bearing surface of the tibial insert when the tibial insert is moved along the track relative to the tibial tray in a generally anterior-posterior direction, and (iii) the tibial insert is freely rotatable about a central axis defined by the stem when the tibial insert is moved along the track relative to the tibial tray in the generally anterior-posterior direction. 7. A mobile tibial assembly comprising: a tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia, the tibial tray including (i) a platform having a convex upper surface, (ii) an anchor extending downwardly from a bottom surface of the platform, and (iii) a channel formed in the convex upper surface of the platform, wherein the channel of the tibial tray is generally parallel to an inboard surface of the platform of the tibial tray, extends from an anterior side of the platform to a posterior side of the platform, and includes a bottom wall that is flat in the generally medial-lateral direction and convex in the anterior-posterior direction, anda tibial insert including a platform having a concave bottom bearing surface having a surface area, and a stem received within the channel of the tibial tray, the stem including a circular neck connected to the bottom bearing surface and a circular flange extending from a distal end of the circular neck, the circular neck having a first diameter and a cross-sectional area that is less than the surface area of the bottom bearing surface, the circular flange having a second diameter greater than the first diameter,wherein (i) the stem of the tibial insert includes a medial surface defining a curved line extending from the anterior side of the tibial insert to the posterior side of the tibial insert when viewed in a plan view, (ii) the stem is movable along the channel relative to the tibial tray, (iii) the convex upper surface of the tibial tray contacts the concave bottom surface of the platform as the stem is moved along the channel relative to the tibial tray in a generally anterior-posterior direction, and (iv) tibial insert is freely rotatable about a central axis defined by the stem as the tibial insert is moved along the track relative to the tibial tray in the generally anterior-posterior direction.