Quadruped Knee Prosthesis Axle Rotation Mechanism

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Solution Overview

Problem

Current knee joint replacement designs for humans are inadequate for quadrupeds like canines and felines due to differing force distributions and anatomical requirements, leading to potential component dislocation and limited application in these species.

Innovation Solution

A total knee replacement prosthesis assembly featuring a femoral component, tibial component, and a bearing component with a transverse bore and post configuration, including a medial-lateral hinge axis and a rotating platform with predefined rotational laxity, to prevent dislocation and accommodate unique quadruped anatomy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a post-in-channel design is used for rotating hinge knee mechanism, then internal and external rotation is enabled, but component dislocation occurs due to distraction

Engineering Contradiction:
Improveinternal and external rotationVSAvoidcomponent dislocation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The bearing component is divided into separate sections with individual transverse bores, allowing independent control of rotational movements. The first bearing component handles internal-external rotation while the second bearing component manages anterior-posterior rotation, preventing dislocation by segmenting the rotational functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Axles are introduced as intermediary elements that connect the bearing components to the tibial and femoral components. These axles act as mediators that transmit rotational movements while maintaining stable connections, preventing direct dislocation between the bearing components and bone-anchored components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If a rotating hinge mechanism is used for severe soft tissue compromise, then stability is improved, but distraction leads to dislocation

Engineering Contradiction:
Improveknee joint stabilityVSAvoiddislocation resistance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The mechanism allows dynamic rotational movements through the two bearing components with different rotational axes. The first bearing component rotates about a mediolateral axis for internal-external rotation, while the second bearing component rotates about an anteroposterior axis for anterior-posterior rotation, providing adaptive stability that responds to soft tissue conditions without causing dislocation.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If human knee replacement designs are used for quadrupeds, then limited application is achieved, but anatomical requirements are not met

Engineering Contradiction:
Improveanatomical adaptabilityVSAvoidclinical function
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The knee joint replacement prosthesis is designed with universal applicability for both quadruped and biped species. The dual-bearing component system with independent rotational capabilities provides multi-functional movement patterns that accommodate the anatomical requirements of different species, making the design versatile while maintaining reliable clinical function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3324893B1Total knee replacement prosthesis assembly
Publication Date: 2020.08.12 FTIZBIONICS LIMITED
  • EP3324893B1 patent drawingFigure 1~2B
  • EP3324893B1 patent drawingFigure 3A~4
  • EP3324893B1 patent drawingFigure 5~6

AI summary

A total knee replacement prosthesis assembly (10) comprising a femoral component (20), a tibial component (30) having a tibial platform (32), and a bearing component (40), the bearing component having an inferior side (40b) and a superior side (40a), the bearing component being adapted to be arranged between the femoral component and tibial platform when assembled,the tibial platform having a post (36) upstanding from it and the bearing component having a post recess (46) in its inferior side for receiving the post, the bearing component being rotatable about the post when assembled, the post and bearing component each having a transverse bore and the assembly further comprising an axle (60), at least part of the axle being received through the transverse bore (38) in the post when assembled and at least part of the axle being received through the transverse bore (52) in the bearing component when assembled, the axle being configured to provide an axis of rotation between the femoral component and bearing component which is fixed relative to the femoral component and the bearing component in use.