Total knee prosthesis with resurfacing and posterior stabilization capability

A total knee prosthesis capable of providing resurfacing to adjacent ends of existing bone structures, as well as to a posterior stabilization to a knee joint, comprising:

• a) a femoral component including:
• i) a medial condyle having an anterior portion, a distal portion and a posterior portion;
• ii) a lateral condyle having an anterior portion, a distal portion and a posterior portion;
• iii) an anterior patella flange interconnecting the anterior portions of the medial and lateral condyles in parallel, spaced apart relation;
• and
• iv) cam member means integral with said medial and lateral condyles and located outboard thereof, said cam member means having an anteriorly located concave cam member surface and a posteriorly located convex cam member surface;
• b) a tibial component including:
• i) multi-radius tibial plateau bearing surface means for receiving said medial and lateral condyles for rolling and sliding movement thereon;
• and
• ii) follower member means integral with said bearing surfaces for receiving the cam surfaces of said cam member means for rotational and sliding movement thereon;
• and
• c) said convex cam member surface being in sliding contact with said follower member means to provide posterior rollback of said condyles on said tibial plateau bearing surface means during flexion, starting at approximately maximum normal hyperextension of flexion, and being completed at an angle less than approximately 40.degree. of flexion,
• wherein said tibial plateau bearing surface means includes:
• a. a medial multi-radius tibial plateau bearing surface means located inboard of said follower means and having an anterior, central and posterior portion for receiving said medial femoral condyle for rolling and sliding movement thereon;
• b. a lateral inboard multi-radius tibial plateau bearing surface means located inboard of said follower means and having an anterior, central and posterior portion for receiving said inboard portion of the lateral femoral condyle for rolling and sliding movement thereon;
• c. a medial outboard-located follower member consisting of a convex follower member surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam member surface and posterior convex cam member surface of the medial cam member means for rolling and sliding movement thereon, said medial concave arcuate follower member surface being connected to a respective posterior portion of the concave arcuate tibial plateau bearing surface means;
• d. a lateral outboard-located follower member consisting of a convex follower member surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam member surface and posterior convex cam member surface of the medial cam member means for rolling and sliding movement thereon, said lateral concave arcuate follower member surface being connected to the respective posterior portion of the concave arcuate tibial plateau bearing surface means;
• and
• e. an interconnecting intercondylar eminence centrally disposed between the medial and lateral multi-radius tibial plateau bearing surface means, said interconnecting eminence being connected to said plateau bearing surface means, and said eminence being removed within a posterior intercondylar portion to provide required clearance for retained anterior and posterior cruciate ligament structures.

A total knee prosthesis capable of providing resurfacing to adjacent ends of existing bone structures, as well as total posterior stabilization to a knee joint, comprising:

• a) a femoral component including:
• i) a medial condyle having an anterior portion, a distal portion and a posterior portion;
• ii) a lateral condyle having an anterior portion, a distal portion and a posterior portion;
• iii) an anterior patella flange interconnecting the anterior portions of the medial and lateral condyles in parallel, spaced apart relation;
• and
• iv) cam member means integral with said medial and lateral condyles and located outboard thereof, said cam member means having an anteriorly located concave cam member surface and a posteriorly located convex cam member surface;
• b) a tibial component including:
• i) multi-radius tibial plateau bearing surface means for receiving said medial and lateral condyles for rolling and sliding movement thereon;
• and
• ii) follower member means integral with said bearing surfaces for receiving the cam surfaces of said cam member means for rotational and sliding movement thereon;
• and
• c) said convex cam member surface being in sliding contact with said follower member means to provide posterior rollback of said condyles on said tibial plateau bearing surface means during flexion, starting at approximately maximum normal hyperextension of flexion, and being completed at an angle less than approximately 40.degree. of flexion,
• wherein said tibial component includes a tibial plateau bearing component containing medial and lateral multi-radius femoro-tibial plateau bearing surface means, an interconnecting centrally disposed eminence and outboard-located medial and lateral follower member means, and a tibial base component connected to an underside of said tibial plateau bearing component by means of a continuous and wedging peripheral and central engaging dovetail structures and preloaded and secured with a screw thread locking means which is installed anteriorly.

A total knee prosthesis capable of providing resurfacing to adjacent ends of existing bone structures, as well as total posterior stabilization to a knee joint, comprising:

• a) a femoral component including:
• i) a medial condyle having an anterior portion, a distal portion and a posterior portion;
• ii) a lateral condyle having an anterior portion, a distal portion and a posterior portion;
• iii) an anterior patella flange interconnecting the anterior portions of the medial and lateral condyles in parallel, spaced apart relation;
• and
• iv) a cam member means integral with said medial and lateral condyles and located outboard thereof, said cam member means having an anteriorly located concave cam member surface and a posteriorly located convex cam member surface;
• b) a tibial component including:
• i) multi-radius tibial plateau bearing surface means for receiving said medial and lateral condyles for rolling and sliding movement thereon;
• and
• ii) follower member means integral with said bearing surfaces for receiving the cam member surfaces of said cam member means for rotational and sliding movement thereon;
• and
• c) said convex cam surface being in congruent contact with said follower member means from approximately the end of posterior rollback to full flexion,
• wherein said tibial plateau bearing surface means includes:
• a. a medial multi-radius tibial plateau bearing surface means located inboard of said follower means and having an anterior, central and posterior portion for receiving said medial femoral condyle for rolling and sliding movement thereon;
• b. a lateral inboard multi-radius tibial plateau bearing surface means located inboard of said follower means and having an anterior, central and posterior portion for receiving said inboard portion of the lateral femoral condyle for rolling and sliding movement thereon;
• c. a medial outboard-located follower member consisting of a convex follower member surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam member surface and posterior convex cam member surface of the medial cam member means for rolling and sliding movement thereon, said medial concave arcuate follower member surface being connected to the respective posterior portion of the concave arcuate tibial plateau bearing surface means;
• d. a lateral outboard-located follower member consisting of a convex follower member surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam member surface and posterior convex cam member surface of the medial cam member means for rolling and sliding movement thereon, said lateral concave arcuate follower member surface being connected to the respective posterior portion of the concave arcuate tibial plateau bearing surface means;
• and
• e. an interconnecting intercondylar eminence centrally disposed between the medial and lateral multi-radius tibial plateau bearing surface means, said interconnecting eminence being connected to said plateau bearing surface means, and said eminence being removed within a posterior intercondylar portion to provide required clearance for retained anterior and posterior cruciate ligament structures.

A total knee prosthesis capable of providing resurfacing to adjacent ends of existing bone structures, as well as total posterior stabilization to a knee joint, comprising:

• a) a femoral component including:
• i) a medial condyle having an anterior portion, a distal portion and a posterior portion;
• ii) a lateral condyle having an anterior portion, a distal portion and a posterior portion;
• iii) an anterior patella flange interconnecting the anterior portions of the medial and lateral condyles in parallel, spaced apart relation;
• and
• iv) a cam member means integral with said medial and lateral condyles and located outboard thereof, said cam member means having an anteriorly located concave cam member surface and a posteriorly located convex cam member surface;
• b) a tibial component including:
• i) multi-radius tibial plateau bearing surface means for receiving said medial and lateral condyles for rolling and sliding movement thereon;
• and
• ii) follower member means integral with said bearing surfaces for receiving the cam member surfaces of said cam member means for rotational and sliding movement thereon;
• and
• c) said convex cam surface being in congruent contact with said follower member means from approximately the end of posterior rollback to full flexion,
• wherein said tibial component includes a tibial plateau bearing component containing medial and lateral multi-radius femoro-tibial plateau bearing surface means, an interconnecting centrally disposed eminence and outboard-located medial and lateral follower member means, and a tibial base component connected to an underside of said tibial plateau bearing component by means of a continuous and wedging peripheral and central engaging dovetail structures and preloaded and secured with a screw thread locking means which is installed anteriorly.

A total knee prosthesis capable of providing resurfacing to adjacent ends of existing bone structures, as well as total posterior stabilization to a knee joint, comprising:

• a. a femoral component including:
• i. a medial condyle having an anterior condyle portion, an inboard (lateral) distal condyle portion with outboard (medial) cam member means and a posterior condyle portion;
• ii. a lateral condyle having an anterior portion, an inboard (medial) distal condyle portion with outboard (lateral) cam member means and a posterior condyle portion;
• iii. an anterior patella flange interconnecting the anterior portions of the medial and lateral condyles in parallel, spaced apart relation;
• and
• iv. a cam member means integrated within the outboard portion of the medial and lateral condyles, said cam members having a concave surface portion anteriorly and a convex cam member surface posteriorly;
• b. a tibial component including:
• i. a medial inboard multi-radius tibial plateau bearing surface means having an anterior, central and posterior portion for receiving said inboard portion of the multi-radius medial femoral condyle for rolling and sliding movement thereon;
• and
• ii. a lateral inboard multi-radius tibial plateau bearing surface means having an anterior, central and posterior portion for receiving said inboard portion of the multi-radius lateral femoral condyle for rolling and sliding movement thereon;
• and
• iii. a medial outboard follower member comprising a convex surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam surface and posterior convex cam member surface of medial cam member means for rotational and sliding movement thereon, said medial outboard concave arcuate follower member surface means being connected with the respective outboard posterior portion of said inboard and outboard concave arcuate tibial plateau bearing surface means;
• and
• iv. a lateral outboard follower member consisting of a convex surface anteriorly and a concave arcuate follower member surface posteriorly for receiving said anterior concave cam surface and posterior convex cam member surface of lateral cam member means for rotational and sliding movement thereon, said lateral outboard concave arcuate follower member surface means being connected with the respective outboard posterior portion of the concave arcuate tibial plateau bearing surface means;
• and
• v. an interconnecting intercondylar eminence centrally disposed between the medial and lateral inboard multi-radius tibial plateau bearing surface means with said interconnecting eminence being connected to said inboard plateau bearing surface means and said eminence being removed within a posterior intercondylar portion to provide required clearance for retained anterior and posterior cruciate ligament structures;
• c. said medial and lateral cam member means being in contact with said respective follower member means from the outset of flexion and said medial and lateral cam member means being in contact with said respective follower member means substantially throughout the entire flexion range of the knee joint, providing uninterrupted posterior (tibia-femur) stabilization.