Prosthetic Adapter Compatibility Test Specimen
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Solution Overview
Problem
The selection of compatible prosthetic components from different manufacturers during revision operations for modular joint prostheses is challenging, often requiring lengthy trial and error processes, which can prolong surgery and lead to complications such as femur separation.
Innovation Solution
A device using a set of test specimens with different inner cones, featuring markings and length measuring scales, allows for precise determination of the fit between an adapter and the outer cone of a prosthetic shaft, ensuring compatibility without removing the existing shaft, by assessing the minimum permissible distance and insertion depth to select the appropriate adapter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If trial and error process is used to select compatible adapters, then compatibility between components from different manufacturers is achieved, but surgical time is excessively prolonged
Solution Approach 1:
The patent applies preliminary action by pre-calculating and marking the minimum permissible distance and insertion depth on the test specimen before surgery. These markings represent pre-determined compatibility criteria that allow the surgeon to quickly assess fit without time-consuming trial and error during the operation.
Solution Approach 2:
The test specimen serves as an intermediary device between the adapter and the outer cone. It mediates the compatibility assessment by providing visual markings that indicate whether the adapter meets the minimum geometric requirements, eliminating the need for direct trial-and-error fitting of the actual adapter.
2Measurement precision
If multiple test specimens with different inner cones are tested, then precise determination of minimum permissible distance and insertion depth is achieved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the compatibility assessment into two distinct measurement functions: minimum permissible distance (assessed by the position of the roof relative to the end face) and insertion depth (assessed by the length measuring scale). Each test specimen is segmented to provide both measurement functions simultaneously.
Solution Approach 2:
The test specimen is designed as a multi-functional tool that simultaneously performs multiple assessment functions: it measures minimum permissible distance, measures insertion depth, and provides visual indication of compatibility. This universal design eliminates the need for multiple separate testing devices.
3Productivity
If visual markings and measuring scales are added to test specimens, then quick and accurate assessment is enabled, but manufacturing complexity increases
Solution Approach 1:
The patent uses visual markings (such as colored zones or painted indicators) on the test specimen to provide immediate visual feedback about compatibility. The marking indicates when the minimum permissible distance is achieved, allowing for rapid visual assessment without requiring complex measurement instruments.
Solution Approach 2:
The markings and measuring scales are pre-applied to the test specimen during manufacturing, converting a complex measurement task into a simple visual reading task during surgery. This preliminary preparation of measurement references enables rapid assessment during the surgical procedure.
Data Source
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AI summary
The invention relates to a method and a device for determining the compatibility between an adapter, which is to be inserted into a third-party joint ball type to be replaced, and an outer cone (10) of a prosthesis shaft of a modular joint prosthesis, which is inserted in the femur during revision surgery. The aim of the invention is to provide a method and a device for determining the compatibility of an adapter of a joint prosthesis, which allow to combine modular components of a joint prosthesis from different manufacturers, to simplify revision surgery and to insert joint balls made of ceramics or metal into an already lying shaft in a precise fit. This aim is solved by a method in which a test body (1) of a set of test bodies having various inner cones, comprising a marker (7) and a length measuring scale (8), is fitted onto the outer cone of the shaft of the joint prosthesis and, subsequently, the adapter fitting on the outer cone of the joint prosthesis is determined by successively testing the inner cones for compliance with an admissible minimum distance between the front faces of the outer cone of the shaft of the joint prosthesis and the inner cone and for compliance with an admissible predefined insertion depth of the outer cone of the shaft of the joint prosthesis in the inner cone of the test body.