Reverse Shoulder Prosthesis Tray Geometry for Lower Onlay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modular reverse shoulder prostheses often result in excessive tensioning of surrounding tissues due to the onlay level, leading to biomechanical issues and potential bone fractures, particularly in the case of modular designs with asymmetrical liners, which affect mobility and mechanical strength.
Innovation Solution
A modular shoulder prosthesis design featuring a tray with a raised edge supporting the joint concave element, creating an asymmetrical outline to reduce the onlay level while maintaining sufficient thickness and support, allowing for different correction angles and improved mobility and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a modular reverse prosthesis with an asymmetrical liner is used, then the correction angle can be adjusted, but the onlay level increases excessively
Solution Approach 1:
The tray is designed with an asymmetrical configuration where the height varies around its circumference. Specifically, the tray has a maximum height and a minimum height at different angular positions, allowing the liner to be positioned at the desired correction angle while maintaining an acceptable onlay level. The asymmetrical tray geometry compensates for the liner's angular orientation, preventing excessive onlay level increase.
Solution Approach 2:
The tray's height is locally optimized at different angular positions to match the specific requirements of the asymmetrical liner. The tray has elevated regions and reduced regions corresponding to the liner's thickness variations, ensuring that the onlay level remains controlled while accommodating the liner's angular correction capability.
2Object-affected harmful factors
If the onlay level is reduced, then tissue tension and bone fracture risk decrease, but the liner thickness may become insufficient
Solution Approach 1:
The asymmetrical tray design allows the liner to maintain adequate thickness in critical load-bearing regions while keeping the onlay level controlled. The tray's variable height profile provides structural support where needed, enabling the liner to be thinner overall without compromising strength, thus reducing tissue tension and fracture risk while preserving mechanical integrity.
3Device complexity
If a symmetrical liner is used, then the design is simpler, but the correction angle cannot be adjusted
Solution Approach 1:
The tray is designed with asymmetrical geometry to compensate for the liner's asymmetry, enabling correction angle adjustment. The asymmetrical tray configuration (with varying height around its circumference) works in conjunction with the asymmetrical liner to provide angular correction capability while maintaining a relatively simple overall design approach.
Data Source
AI summary
A modular reverse shoulder prosthesis, comprising: a stem (110) comprising a tapered body (111) and a first annular housing (112); a tray (120) comprising a dome element (121) for insertion into the first annular housing (112), and further comprising a second annular housing (122); a liner (130) comprising an engaging element (131) for at least partial insertion into the dome element (121), and further comprising a joint concave element (132) configured for coupling with the second annular housing (122). The second annular housing (122) of the tray (120) comprises a raised edge (123) configured to support the joint concave element (132) and which defines an overall outline having a different development in height at least in diametrically opposite portions (123a; 123b) of the tray (120).