# US 2018/0021143 A1 · Motion facilitating tibial components for a knee prosthesis > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021143 A1 - Document ID: US20180021143A1 - Status: Published application - Kind: A1 - Application number: 15/703,692 - Filed: 2017-09-13 - Published: 2018-01-25 - Earliest claimed: 2010-09-10 - Assignees: Zimmer, Inc. - Applicants: Zimmer, Inc. - Inventors: Raymond C. Parisi; Katherine M. Rettig; Jeff Blaylock - Web page: https://patentgrep.com/patent/US20180021143A1 ## CPC - A61F 2/389: {Tibial components (A61F2/3868 takes precedence)} - A61F 2/3886: {for stabilising knees against anterior or lateral dislocations} - A61F 2/3868: {with sliding tibial bearing} - A61F 2002/30387: {Dovetail connection} - A61F 2002/30616: {Sets comprising a plurality of prosthetic parts of different sizes or orientations} - A61F 2220/0033: made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract An orthopaedic tibial prosthesis includes a tibial baseplate sized and shaped to cover substantially all of a resected proximal tibial surface, and a tibial bearing component sized to leave a posteromedial portion of the tibial baseplate exposed when the tibial bearing component is mounted to the baseplate. The exposed posteromedial portion of the tibial baseplate includes a chamfered profile which cooperates with a correspondingly chamfered profile at a posteromedial edge of the tibial bearing component to create a substantially continuous chamfer extending from the resected tibial surface to the medial articular surface of the tibial bearing component. Advantageously, this chamfer leaves an absence of material (i.e., a relief or void) at the posteromedial edge of the tibial prosthesis, thereby enabling deep flexion of the prosthesis without impingement between the tibial prosthesis and adjacent anatomic tissues or prosthetic structures. ## Claims ### Claim 1 (canceled) ### Claim 2 A tibial prosthesis comprising: a bearing component comprising: a bearing distal surface; an opposing bearing proximal surface defining a lateral articular surface and a medial articular surface; and a bearing peripheral wall disposed between the bearing distal and proximal surfaces; and a baseplate configured to couple to the bearing component, the baseplate comprising: a baseplate distal surface configured for contacting a bone surface; an opposing baseplate proximal surface having a medial compartment and a lateral compartment, the bearing component mountable to the tibial baseplate; and a baseplate peripheral wall disposed between the baseplate proximal and distal surfaces, the baseplate peripheral wall including a baseplate medial-posterior wall extending distally and posteriorly toward the baseplate distal surface; wherein the baseplate medial-posterior wall extends in a posterior direction beyond a posterior medial edge of the bearing component such that a posterior most portion of the baseplate medial-posterior wall does not interface with the bearing component and is exposed when the baseplate is coupled to the bearing component. ### Claim 3 (depends on 2) The tibial prosthesis of claim 2, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer extends across less than an entirety of a proximal/distal distance of the baseplate medial-posterior wall. ### Claim 4 (depends on 2) The tibial prosthesis of claim 2, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer extends across substantially an entirety of a proximal/distal distance of the baseplate medial-posterior wall. ### Claim 5 (depends on 2) The tibial prosthesis of claim 2, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer defines one of an arcuate profile or a linear profile. ### Claim 6 (depends on 2) The tibial prosthesis of claim 2, wherein the bearing peripheral wall includes a bearing medial-posterior chamfer extending distally and posteriorly from the medial articular surface toward the bearing distal surface. ### Claim 7 (depends on 6) The tibial prosthesis of claim 6, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the bearing medial-posterior chamfer and the baseplate chamfer form one of a substantially continuous or a substantially discontinuous chamfer that extends proximally and anteriorly substantially from a posterior-medial edge of the baseplate to substantially the medial articular surface. ### Claim 8 (depends on 2) The tibial prosthesis of claim 2, wherein the baseplate medial-posterior wall and the bearing peripheral wall at a medial-posterior section are configured to cooperate to create a relief from a femur when implanted such that there is a space between the femur and both baseplate medial-posterior wall and the bearing peripheral wall at the medial-posterior section when the femur is in a deep flexion orientation with respect to the tibial prosthesis. ### Claim 9 (depends on 2) The tibial prosthesis of claim 2, wherein a medial portion of the bearing component is biased anteriorly relative to a lateral portion such that the baseplate medial-posterior wall is exposed, and wherein the lateral articular surface substantially completely covers a lateral compartment and extends further posterior than the medial articular surface. ### Claim 10 (depends on 2) The tibial prosthesis of claim 2, wherein the bearing component comprises a recess formed between the bearing peripheral wall and the bearing distal surface, and the baseplate includes a projection configured to engage with the recess when the bearing component is mounted to the tibial baseplate. ### Claim 11 A tibial prosthesis comprising: a bearing component comprising: a bearing distal surface; an opposing bearing proximal surface defining a lateral articular surface and a medial articular surface; and a bearing peripheral wall disposed between the bearing distal and proximal surfaces; and a baseplate configured to couple to the bearing component, the baseplate comprising: a baseplate distal surface configured for contacting a bone surface; an opposing baseplate proximal surface having a medial compartment and a lateral compartment, the bearing component mountable to the tibial baseplate; and a baseplate peripheral wall disposed between the baseplate proximal and distal surfaces, the baseplate peripheral wall including a baseplate medial-posterior wall extending distally and posteriorly toward the baseplate distal surface; wherein the baseplate medial-posterior wall extends in a posterior direction beyond a posterior medial edge of the bearing component, wherein the baseplate medial-posterior wall and the bearing peripheral wall at a medial-posterior section together extend proximally and anteriorly substantially from a posterior-medial edge of the baseplate to substantially the medial articular surface to create a relief from a femur when implanted such that there is a space between the femur and both baseplate medial-posterior wall and the bearing peripheral wall at the medial-posterior section when the femur is in a deep flexion orientation with respect to the tibial prosthesis. ### Claim 12 (depends on 11) The tibial prosthesis system of claim 11, wherein a posterior most portion of the baseplate medial-posterior wall does not interface with the bearing component and is exposed when the baseplate is coupled to the bearing component. ### Claim 13 (depends on 11) The tibial prosthesis of claim 11, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer extends across less than an entirety of a proximal/distal distance of the baseplate medial-posterior wall. ### Claim 14 (depends on 11) The tibial prosthesis of claim 11, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer extends across substantially an entirety of a proximal/distal distance of the baseplate medial-posterior wall. ### Claim 15 (depends on 11) The tibial prosthesis of claim 11, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the baseplate chamfer defines one of an arcuate profile or a linear profile. ### Claim 16 (depends on 11) The tibial prosthesis of claim 11, wherein the bearing peripheral wall includes a bearing medial-posterior chamfer extending distally and posteriorly from the medial articular surface toward the bearing distal surface. ### Claim 17 (depends on 16) The tibial prosthesis of claim 16, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, and wherein the bearing medial-posterior chamfer and the baseplate chamfer form a substantially continuous chamfer that extends proximally and anteriorly substantially from the posterior-medial edge of the baseplate to substantially the medial articular surface. ### Claim 18 (depends on 11) The tibial prosthesis of claim 11, wherein a medial portion of the bearing component is biased anteriorly relative to a lateral portion such that the baseplate medial-posterior wall is exposed, and wherein the lateral articular surface substantially completely covers a lateral compartment and extends further posterior than the medial articular surface. ### Claim 19 A tibial prosthesis comprising: a bearing component comprising: a bearing distal surface; an opposing bearing proximal surface defining a lateral articular surface and a medial articular surface; and a bearing peripheral wall disposed between the bearing distal and proximal surfaces; and a baseplate configured to couple with the bearing component, the baseplate comprising: a baseplate distal surface configured for contacting a bone surface; an opposing baseplate proximal surface having a medial compartment and a lateral compartment, the bearing component mountable to the tibial baseplate; and a baseplate peripheral wall disposed between the baseplate proximal and distal surfaces, the baseplate peripheral wall including a baseplate medial-posterior wall extending distally and posteriorly toward the baseplate distal surface; wherein the baseplate medial-posterior wall extends in a posterior direction beyond a posterior medial edge of the bearing component, wherein a medial portion of the bearing component is biased anteriorly relative to a lateral portion such that the baseplate medial-posterior wall is exposed, and wherein the lateral articular surface substantially completely covers a lateral compartment and extends further posterior than the medial articular surface. ### Claim 20 (depends on 19) The tibial prosthesis of claim 19, wherein the baseplate medial-posterior wall and the bearing peripheral wall at a medial-posterior section together extend proximally and anteriorly substantially from a posterior-medial edge of the baseplate to substantially the medial articular surface to create a relief from a femur when implanted such that there is a space between the femur and both baseplate medial-posterior wall and the bearing peripheral wall at the medial-posterior section when the femur is in a deep flexion orientation with respect to the tibial prosthesis. ### Claim 21 (depends on 19) The tibial prosthesis of claim 19, wherein the baseplate medial-posterior wall comprises a baseplate chamfer, wherein the bearing peripheral wall includes a bearing medial-posterior chamfer extending distally and posteriorly from the medial articular surface toward the bearing distal surface, and wherein the bearing medial-posterior chamfer and the baseplate chamfer form one of a substantially continuous or a discontinuous chamfer that extends proximally and anteriorly substantially from the posterior-medial edge of the baseplate to substantially the medial articular surface.