Stabilized Knee Prosthesis Ball Coupling Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current knee prostheses fail to adequately mimic the natural knee's rotational stability and kinematics, particularly in replicating the role of cruciate and collateral ligaments, leading to suboptimal performance and stability during flexion and extension.
Innovation Solution
A knee prosthesis design featuring a femoral component, a tibial component with a ball, and a coupling component that articulates and repositions the ball between spherical end portions within an internal cavity, mimicking the natural knee's kinematics and providing rotational stability through a mechanism that engages and disengages during flexion and extension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the knee prosthesis is constrained to supply the stability ordinarily provided by the sacrificed ligaments, then rotational stability is improved, but the device complexity increases
Solution Approach 1:
The coupling component acts as an intermediary element that connects the femoral and tibial components while providing rotational stability. It includes a ball receiving cavity that guides the ball through spherical portions, creating a controlled rotation path that mimics natural knee kinematics without requiring complex multi-mechanism systems
Solution Approach 2:
The coupling component incorporates spherical portions within its ball receiving cavity that guide the ball's movement. This spherical geometry provides rotational stability through curved surfaces while maintaining simplicity, allowing the ball to rotate smoothly between spherical end portions without requiring flat surfaces or complex约束 mechanisms
2Device complexity
If the knee prosthesis uses a fixed coupling mechanism, then structural simplicity is improved, but the ability to mimic natural knee kinematics deteriorates
Solution Approach 1:
The coupling component is designed with movable spherical portions within its ball receiving cavity, allowing it to dynamically adapt its configuration as the ball moves between spherical end portions during flexion and extension. This dynamic behavior enables the prosthesis to mimic natural knee kinematics across different ranges of motion while maintaining a relatively simple overall structure
Solution Approach 2:
The coupling component's ball receiving cavity is segmented into multiple spherical portions that guide the ball through different positions. This segmentation allows the coupling mechanism to provide different kinematic constraints at different flexion angles, replicating the complex motion patterns of the natural knee through a series of simple spherical guides rather than a single complex mechanism
Data Source
AI summary
A knee prosthesis includes a femoral component, a tibial component, and a coupling component interconnecting the femoral component and the tibial component. The tibial component includes ball. The femoral component is configured to move relative to the tibial component. The coupling component defines an internal cavity including a first spherical end portion and a second spherical end portion. The internal cavity is dimensioned to receive the ball of the tibial component. The ball is repositioned between the first spherical end portion and the second spherical end portion of the internal cavity upon movement of the femoral component relative to the tibial component.