Prosthetic Cap with Cable Loop Cutting Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing prosthetic implant insertion tools face challenges in applying sufficient force without compromising the structural strength or articulating properties of the implant, particularly with metal-on-metal joints where mechanical features on the inner surface are not feasible, and there is a need for a cost-effective solution that allows for easy removal of cables.
Innovation Solution
A cap system comprising an impaction plate with cable loops, clamping means, and cutting means that allows for secure attachment and easy removal of cables, using a plastics material for the impaction plate and a guillotine-style cutting mechanism to sever the cable loops, ensuring robust attachment and minimal impact on the implant's structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical feature is provided on the inner hemisphere of the metal shell for tool gripping, then the insertion tool can positively grip the cup, but the mechanical feature compromises the structural strength and articulating properties of the prosthesis
Solution Approach 1:
The mechanical feature for tool gripping is extracted from the inner hemisphere of the metal shell and relocated to the outer surface. This allows the insertion tool to positively grip the cup without compromising the structural integrity and articulating properties of the prosthesis, as the outer surface features do not interfere with the internal structure or joint function.
Solution Approach 2:
An intermediary element (the outer surface mechanical feature) is introduced to provide the gripping interface between the insertion tool and the cup. This mediator transfers the insertion forces from the tool to the cup without requiring modifications to the critical inner hemisphere surface, thus maintaining both grip strength and structural integrity.
2Manufacturing precision
If multiple sized tools are provided to fit different cup sizes, then correct positioning and engagement can be achieved, but the cost implications for hospitals increase
Solution Approach 1:
The mechanical feature on the outer surface is designed with universal dimensions and geometry that can accommodate multiple cup sizes. This allows a single insertion tool design to correctly engage and position cups of varying sizes, eliminating the need for hospitals to purchase and maintain multiple specialized tools while maintaining positioning accuracy.
Solution Approach 2:
The mechanical feature is segmented into standardized components with consistent dimensions that can interface with different cup sizes through modular adaptation. This segmentation allows one tool design to serve multiple functions across different implant sizes, reducing the total number of tools required.
3Loss of substance
If the wall thickness of the shell is kept to a minimum, then material usage is reduced, but the tool cannot grip the wall directly
Solution Approach 1:
The gripping interface is moved from the radial dimension (wall thickness) to the axial dimension (outer surface). By placing the mechanical feature on the outer surface rather than requiring thick walls for tool engagement, the design maintains minimal wall thickness for material efficiency while providing adequate tool accessibility through the external feature.
Data Source
AI summary
A cap for use during the insertion of a prosthesis comprising: an impaction plate; an least one cable loop for connecting the impaction plate to a prosthesis; clamping means for attaching the at least one cable means to the impaction plate; and cutting means for severing the at least one loop at one point along its length.