# US 2019/0167323 A1 · Prosthesis > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167323 A1 - Document ID: US20190167323A1 - Status: Published application - Kind: A1 - Application number: 16/265,030 - Filed: 2019-02-01 - Published: 2019-06-06 - Earliest claimed: 2009-10-22 - Assignees: Pranesh Kumar - Inventors: Pranesh KUMAR - Web page: https://patentgrep.com/patent/US20190167323A1 ## CPC - A61B 17/8061: {specially adapted for particular bones (A61B17/70 and A61B17/74 take precedence)} - A61B 2017/567: {Joint mechanisms or joint supports in addition to the natural joints and outside the joint gaps} - A61B 2017/568: {produced with shape and dimensions specific for an individual patient} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Osteoarthritis (OA) is the most common disease affecting human joints. Mechanical stress through the joint is one of the most important independent etiological factors. The present invention provides a prosthesis that by passes some of the stress from the joint without destroying the joint surface. It allows may provide a full range of joint movement, while sharing the load with the physiological joint, thereby maintaining the viability of the physiological joint surface. In addition, the prosthesis can accommodate native soft tissue structures in or around the joint, such as ligaments. ## Claims ### Claim at position 1 1-13. (canceled) ### Claim 14 A knee prosthesis for insertion into a patient's knee joint, including a first plate configured for fixing to the patient's femur forming part of the knee joint, a first bearing surface associated with the first plate, wherein the first bearing surface is a shape having a series of involute mid points falling on a spiral so that the first bearing surface is shaped to conform to the articulating surface of the condoyles of the femur, a second plate configured for fixing to the patient's tibia forming part of the knee joint, a second bearing surface associated with the second plate, wherein the second bearing surface is shaped to conform to the articulating surface of the condoyles of the tibia, and wherein the shapes of the bearing surfaces ensure that in-use the bearing surfaces cooperate with each other to guide the movement of the patient's tibia relative to the patient's femur through a desired range of motion corresponding to the patient's native knee joint. ### Claim 15 (depends on 14) A prosthesis as claimed in claim 14, wherein a pair of first plates are fixed on the lateral and medial margins of the femur respectively, and a pair of second plates are fixed on the lateral and medial margins of the tibia respectively. ### Claim 16 (depends on 14) A prosthesis as claimed in claim 14, wherein the bearing surfaces cooperates to provide lateral movement and axial rotation of the knee joint. ### Claim 17 (depends on 14) A prosthesis as claimed in claim 14, including a deformable component configured to transfer a portion of force applied through the joint into cartilage in the joint. ### Claim 18 (depends on 17) A prosthesis as claimed in claim 17, wherein the deformable component has material properties such that it deforms less than or equal to the joints native cartilage. ### Claim 19 (depends on 14) A prosthesis as claimed in claim 14, wherein the first and second plates include a plurality of apertures. ### Claim 20 (depends on 19) A prosthesis as claimed in claim 19, wherein at least some of the apertures are generally triangular in shape and each have a point. ### Claim 21 (depends on 20) A prosthesis as claimed in claim 20, wherein the point of the triangular apertures are aligned to face toward the joint surface. ### Claim 22 (depends on 14) A prosthesis as claimed in claim 14, wherein a plurality of fastening rods extend across the joint between each of said first plates. ### Claim 23 (depends on 14) The prosthesis as claimed in claim 14, wherein the first plate is shaped and configured to be attached to the anteromedial and/or anterodistal ends of femur. ### Claim 24 (depends on 14) The prosthesis as claimed in claim 14, wherein the second plate is shaped and configured to be attached to the anteromedial and/or anterodistal ends of the tibia. ### Claim 25 (depends on 14) The prosthesis as claimed in claim 14, wherein the bearing surfaces of the first plate are shaped to follow the lateral and/or medial borders of the native knee joint. ### Claim 26 (depends on 14) The prosthesis as claimed in claim 14, wherein the first plate and the second plate are shaped so that they do not extend into a gap between the condoyles of the femur and the tibia which is bounded by the lateral and medial edges of the condoyles of the femur and the tibia. ### Claim 27 (depends on 14) The prosthesis as claimed in claim 14, where the second bearing surface is shaped to correspond to the middle two thirds of the lateral border of articulating surfaces of the knee joint. ### Claim 28 (depends on 14) The prosthesis as claimed in claim 14, wherein the first plate and the second plate are configured to in-use substantively transfer stress from the joint and distribute the force to the tibia and femur at locations away from the knee joint. ### Claim 29 (depends on 28) The prosthesis as claimed in claim 28, wherein the first place has a surface that is shaped to confirm to a lateral or medial surface of the condoyle of the femur. ### Claim 30 (depends on 14) The prosthesis as claimed in claim 14, wherein the second plate has a surface that is shaped to confirm to a lateral or medial surface of the condoyle of the tibia. ### Claim 31 (depends on 14) The prosthesis as claimed in claim 14, wherein the bearing surfaces of the first plate and the second plate are shaped to accommodate locking of the knee at extension. ### Claim 32 (depends on 14) The prosthesis as claimed in claim 14, wherein the bearing surfaces of the first plate and the second plate are broader posteriorly to accommodate rotation and sideway motion of the knee in flexion. ### Claim 33 (depends on 14) The prosthesis as claimed in claim 14, wherein the bearing surface of the first plate includes a region having slightly concave shape to allow for the rotation and locking of the knee in extension. ### Claim 34 (depends on 14) The prosthesis as claimed in claim 14, wherein the bearing surface of the first plate has a length in the range of 12-18 mm. ### Claim 35 (depends on 14) The prosthesis as claimed in claim 14, wherein the first plate has a side edge and a notch which extends inwardly from the side edge of the plate. ### Claim 36 (depends on 14) The prosthesis as claimed in claim 14 including a component configured having a shape corresponding to the junction between the side edge of the femoral plate and the notch. ### Claim 37 (depends on 36) The prosthesis as claimed in claim 36, wherein the component and the femoral component are configured to interlock to each other.