US 2025/0025311 A1Published application

Lateral and medial pivoting knee prosthesis

OwnerWilliam Andrew Hodgeinventor

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Abstract

An implantable, asymmetrical right or left knee prosthesis for the arthritic, aging, ligament-deficient knee comprising a femoral component, a tibial component and a patella component, forming three interactive knee compartments mainly the lateral, medial, and femoral patellar compartments, articulating together with a dual, axial pivot knee motion. This dual pivot motion pattern is accomplished by four femoral component radii coacting with four reciprocal proximal tibial surface recesses (in a variety of locations on the tibia based on surgeon choice and patient anatomy), accomplishing initial external femur rotation on the tibia (first pivot location), guiding alignment of the femoral-patellar groove with the patellar quadriceps muscle providing knee strength, durability, and stability. The second pivot point develops with the minor femoral radius in the opposite knee compartment to guide internal rotation of the femur on the tibia to prevent boney impingement of the femur on the tibia and allow deep flexion activities.

Claims16

Dependent claims

A dual pivot right or left knee prosthesis comprising:

(a) a femoral component configured for mounting to a distal end of a right or left femur, said femoral component comprising a lateral condyle and a medial condyle, each condyle having a major radius and a minor radius located posteriorly on each condyle for a total of four condylar radii on a right or left femoral component;
wherein the major radii of both condyles on the right or left femoral component are located on a distal surface of the condyles with the major radius of the lateral condyle having a radius that is equal to or up to 30 percent smaller than the major radius in the medial condyle,
wherein the minor radii are located posteriorly on a right or left femoral component with the minor radius of the lateral condyle having a radius which is the same as or smaller than the minor radius on the medial condyle;
(b) two tibial configurations for a right or left tibial plate having medial and lateral sides, said tibial plate comprising four tibial plate recesses corresponding to the four femoral condylar radii, each of said four tibial plate recesses lying medially and laterally, with two of said four tibial plate recesses being hemispherical and two being trough-like or curved, half-pipe shape, one hemispherical and one trough-like or curved, half-pipe shape recess are located on each of the medial and lateral aspect of the tibial plate;
wherein the tibial plate recesses are constructed and arranged to provide a lateral or medial stable femoral pivot point while gliding in an opposite compartment, thereby providing external knee rotation in early flexion allowing the femur to eternally rotate, engaging patella/quadriceps power in early flexion, and then internal knee rotation in late flexion, a second pivot point occurring during deep knee flexion guiding internal rotation motion of the femur on the tibia which avoids boney impingement and allows deep knee flexion,
wherein, if the medial side is the stable major radii pivot point to begin flexion, the major radius of the medial femoral condyle fits into the medial hemispherical tibial recess during early knee flexion starting the external rotation pivoting and causing the lateral femoral condyle major radius to glide posteriorly in the lateral curved trough-like tibial recess;
wherein if the stable pivot point to begin knee flexion is chosen on the lateral side, then the major radius of the lateral femoral condyle fits into the lateral tibial hemispherical recess to begin the external rotation motion of the knee causing the major radius of the medial femoral condyle to glide anteriorly in the medial tibial trough-like recess, thereby during early flexion, the medial or lateral pivot location of the knee is customized to a particular knee with either medial or lateral axial pivoting in a first half of a knee flexion cycle.

4 more elements

A method of stabilizing a knee comprising:

mounting a prosthesis for replacing at least a portion of a right or left knee joint between the distal end of a femur and the proximal end of a tibia wherein the prosthesis comprises:
(a) a right or left femoral implant for mounting to a distal end of a right or left femur comprising a lateral condyle and a medial condyle, each condyle having a major radius and a minor radius for a total of four condylar radii on the femoral component;
wherein
1. the major radii (distal) of the femoral condyles on the right or left femoral implant are located at the distal surface of the medial and lateral condyles with the major radius of the lateral condyle having a major radius that is equal to or up to 30 percent smaller than the corresponding major radius in the medial condyle;
and
2. the minor radii are located posteriorly on the medial and lateral condyles of the right or left femoral implant with the minor radius of the lateral condyle having a radius which is equal to or up to 30 percent smaller than a corresponding minor radius on the medical condyle;
and
(b) a right or left knee tibial plate having medial and lateral sides each with two recesses (total of four tibial recesses), comprising;
1. two tibial implant hemispherical recesses correspond to the major and minor femoral radii, wherein a position of each recess on the tibial implant is for a right or left knee and starts either medial or lateral, thus providing two tibial configurations for each left or right knee depending on the chosen location of the first pivot (major radius) point, either medial or lateral knee compartment, wherein for early flexion, the femur rotates externally on the tibia to align the femur with the patellar/quadriceps muscle;
wherein if the first pivot point is medial, then the tibial shape will be made according to this configuration or if the first pivot point is lateral, the tibial shape will be according to that pivot location accommodating this first pivot motion with the non-pivoting femoral condyle which glides in the curved trough in the opposite compartment) guiding this initial external femoral rotation.
2. the two curved trough tibial recesses forming a curved half-pipe shape for the smooth gliding of the non-pivoting femoral condyle, thus providing smooth translation while rotating around the stable pivot point initially guiding external rotation of the femur on the tibia during the first half of the knee flexion cycle and aligning the patellar/quadriceps muscle for maximal knee stability and strength, and then a second pivot point utilizing the minor femoral radii is created in the opposite knee compartment from the first pivot location with the minor radius of the opposite femoral condyle, guiding internal rotation of the femur which avoids boney impingment during the second half of the knee flexion cycle.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/828,412Filed 9 Sep 2024
Priority: 22 Jul 2015
Published: 23 Jan 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

A61F 2/3836
For elbows or knees: special connection between upper and lower leg, e.g. constrained
A61F 2/38
Joints: for elbows or knees
A61F 2/3859
For elbows or knees: femoral components
A61F 2/3886
For elbows or knees: for stabilising knees against anterior or lateral dislocations

Family

Application62/195,367Us provisional application · filed 22 Jul 2015
Application15/746,200Continuation in part · filed 19 Jan 2018
Application18/828,412Continuation in part
US 12,083,019 B2Related patent
US 2020/0085583 A1Published application
US 2025/0025311 A1This patent

From the US filing history. Foreign family members aren’t listed.