Knee Prosthetic Meniscal Component Rotation Guide
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Solution Overview
Problem
Existing knee joint endoprostheses have deficits in functionality, particularly in simulating natural knee kinematics and stabilizing the joint, especially in cases of missing cruciate ligaments, leading to reduced quality of life for patients.
Innovation Solution
The knee joint endoprosthesis features a meniscus part mounted on the tibia that can rotate about a medial axis, with a rotation guide device comprising cooperating guide elements on the femur and tibia parts, allowing for off-center rotation and improved stabilization, simulating the function of missing cruciate ligaments and enhancing quadriceps performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional knee joint endoprosthesis is used, then the basic joint replacement function is provided, but the functionality in simulating natural knee kinematics and stabilizing the joint is insufficient
Solution Approach 1:
The prosthesis is divided into functionally independent components: a femoral component, a tibial component, and a meniscal component that can rotate independently about a medial axis. This segmentation allows each component to perform its specific function while collectively simulating natural knee kinematics and providing stabilization.
Solution Approach 2:
The meniscal component is designed with dynamic rotational freedom about a medial axis, allowing it to adapt its orientation during knee flexion and extension. This dynamic behavior mimics the natural movement of the meniscus in a healthy knee, improving both kinematic simulation and joint stabilization.
2Adaptability or versatility
If the meniscus part is made fixed relative to the tibia part, then structural simplicity is achieved, but physiological knee kinematics cannot be reconstructed
Solution Approach 1:
The rotation guide device acts as an intermediary mechanism between the tibial component and the meniscal component. It includes guide surfaces that constrain the meniscal component's rotation to a specific path about the medial axis, enabling physiological kinematics while controlling the complexity through geometric constraints rather than complex mechanical linkages.
3Reliability
If cruciate ligaments are present, then natural joint stabilization is provided, but in cases of missing cruciate ligaments, joint stability is compromised
Solution Approach 1:
The rotation guide device enables the meniscal component to self-stabilize the joint through its constrained rotational movement about the medial axis. This self-service mechanism provides stabilization that compensates for missing cruciate ligaments without requiring additional active control systems or complex mechanical structures.
Data Source
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AI summary
The invention relates to a knee endoprosthesis comprising a femoral component, a tibial component, and a meniscal component located between the femoral component and the tibial component. The meniscal component is rotatably mounted on the tibial component about a medially extending axis of rotation. A rotational guidance device is provided to force a rotational movement of the meniscal component relative to the tibial component about the axis of rotation as a result of a pivoting movement of the femoral component and the tibial component relative to each other about a pivot axis extending transversely to the axis of rotation. The rotational guidance device comprises cooperating first and second guide elements, which are arranged or formed on the femoral component on one side and on the tibial component on the other.