Capture Element Limits Distraction in Constrained Prosthetic Knee
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Constrained knee prostheses with hinge posts often face issues with distraction and luxation due to insufficient soft tissue, leading to pain and complications for patients, as they lack mechanisms to effectively limit the movement of the femoral component relative to the tibial baseplate and bearing component.
Innovation Solution
The implementation of a capture element and bushing system that limits distraction by allowing a controlled degree of movement between the femoral and tibial components, using threaded or snap-fit configurations to position the hinge post and capture element, thereby preventing excessive movement and luxation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the femoral component is allowed to move freely relative to the tibial baseplate, then the knee joint has greater range of motion, but distraction and luxation occur due to insufficient soft tissue
Solution Approach 1:
A capture element is introduced as an intermediary component between the femoral component and tibial baseplate. This capture element engages with the hinge post to limit distraction while still permitting controlled movement, thus preventing luxation without completely restricting range of motion in patients with insufficient soft tissue
2Reliability
If a capture element is added to limit distraction, then joint stability is improved, but device complexity increases
Solution Approach 1:
The capture element is integrated with existing components of the hinge post assembly. The capture element engages with the hinge post that is already part of the constrained knee design, merging the distraction limitation function with the existing mechanical linkage rather than adding completely separate systems
Data Source
AI summary
The techniques described herein relate to a prosthesis assembly. The prosthesis assembly may include a femoral component, a tibial bearing component engaged by the femoral component and a tibial baseplate. The tibial baseplate can include a bushing received in a recess in the tibial baseplate and a hinge post coupled to the femoral component and the bushing. The hinge post can be at least partially received by the bushing. A prosthesis assembly may include a capture element coupled to the tibial baseplate. The capture element can be engaged by at least one of the bushing or the hinge post to limit distraction of the femoral component from the tibial bearing component and tibial baseplate.