Femoral Sizing Guide Sliding Superstructure Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing femoral sizing guides for knee replacement surgeries are complex, with multiple components increasing costs and the risk of incorrect block selection or pin placement, limiting flexibility in selecting and orienting femoral prostheses relative to the distal femur.
Innovation Solution
A femoral sizing guide with a body and superstructure that rest against the resected femoral surface, featuring sliding and rotating components to align guide holes relative to the anterior or posterior cortex, allowing for accurate determination of alignment axes and rotation positions, reducing the number of components and enhancing flexibility in surgical approaches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple separate components are used in the femoral sizing guide, then the guide can provide comprehensive measurement and positioning functions, but the device complexity increases and the risk of incorrect block selection or pin placement increases
Solution Approach 1:
The patent combines multiple separate components (body, superstructure, guide holes, alignment axes) into a single integrated femoral sizing guide device. The guide holes are formed directly within the body structure, and the alignment axes are defined by the spatial relationship between these integrated features, eliminating the need for separate measurement and positioning tools while reducing the risk of incorrect placement.
Solution Approach 2:
The femoral sizing guide is designed as a universal tool that performs multiple functions: measuring femoral dimensions, determining prosthesis size, establishing alignment axes, and guiding pin placement all within a single device. The body and superstructure work together to provide both measurement and positioning capabilities, replacing what would traditionally require multiple specialized instruments.
2Measurement precision
If multiple separate components are used in the femoral sizing guide, then comprehensive measurement functions can be provided, but the cost of the device increases
Solution Approach 1:
The patent integrates measurement and positioning functions into a single device structure. The body and superstructure are designed as unified components that together provide all necessary measurement capabilities for determining prosthesis size, eliminating the need for multiple separate measuring instruments and reducing overall device cost.
3Adaptability or versatility
If the femoral sizing guide uses fixed components, then the structure is simple, but the flexibility in selecting and orienting femoral prostheses is limited
Solution Approach 1:
The patent incorporates movable and adjustable elements within the femoral sizing guide. The superstructure can be positioned at different heights relative to the body, and the guide holes can be aligned at various orientations. This dynamic capability allows the guide to adapt to different prosthesis sizes and rotational alignments while maintaining a relatively simple overall structure.
Data Source
AI summary
A femoral sizing guide comprises a body, a superstructure and a stylus. The body has feet extending underneath and resting against posterior condylar surfaces of the femur and an extension component. The superstructure is slidable on the extension component and the extension component is rotatable with respect to the feet. The stylus may be coupled to the superstructure. The superstructure has a first guide hole defining a first alignment axis and the extension component has a second guide hole defining a second alignment axis. The distance between the first and second guide holes varies as the superstructure slides relative to the body. A method of locating an alignment axis on a resected femoral surface at a distal end of a femur which is transverse to the longitudinal axis of the femur using the femoral sizing guide is also disclosed.