Modular Endoprosthesis Shaft Rotation Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing modular shaft systems for endoprostheses face challenges in adjusting and securing the rotational orientation of components after implantation, particularly when the ends of the shaft are not accessible.
Innovation Solution
A modular shaft system with a rotation piece as a further module element, equipped with a self-contained rotation adjustment device and a clamping device for blocking rotation, allowing for adjustable rotation and secure fixation in a compact and accessible form.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a modular shaft system with plug connections is used, then the shaft can be assembled from multiple elements, but the rotational orientation cannot be adjusted after implantation when the ends are not accessible
Solution Approach 1:
The shaft is divided into multiple modular elements that can be assembled together, with a specific element (rotation element) that contains the rotation adjustment mechanism. This segmentation allows the adjustment function to be isolated in a accessible location while maintaining the modular assembly structure.
Solution Approach 2:
A rotation element is introduced as an intermediary component between the shaft elements. This intermediate element contains the rotation adjustment device and can be accessed from the side of the shaft, serving as a mediator that enables rotation adjustment without requiring access to the shaft ends.
2Reliability
If a screw fitting is used to secure rotational orientation, then the elements can be blocked in rotation, but the actuation requires accessibility of the upper and lower ends of the shaft
Solution Approach 1:
The rotation element acts as an intermediary that houses the rotation blocking mechanism. It provides a central access point for actuation that is accessible from the side of the shaft, eliminating the need to access the shaft ends while maintaining reliable rotation blocking through the clamping device.
Solution Approach 2:
The access point for actuation is moved from the longitudinal dimension (shaft ends) to the radial dimension (side access). This dimensional change allows the rotation blocking mechanism to be actuated from a accessible location without compromising the reliability of the blocking function.
3Ease of operation
If the shaft ends are made accessible for adjustment, then rotation can be adjusted, but this is not possible after implantation when the ends are not accessible
Solution Approach 1:
The rotation element serves as an intermediary that provides accessibility for adjustment from the side of the shaft rather than requiring access to the shaft ends. This intermediate access point remains available after implantation, ensuring both ease of operation and reliability for post-implantation adjustment.
Solution Approach 2:
The rotation adjustment mechanism is preliminarily positioned within the rotation element during assembly, with the access point prepared in advance. This preliminary arrangement ensures that the adjustment function is ready for immediate use after implantation without requiring access to the shaft ends.
4Adaptability or versatility
If a rotation adjustment device is added to the shaft system, then rotational orientation can be adjusted, but the device complexity increases
Solution Approach 1:
The rotation adjustment device is merged with the modular shaft elements by integrating it into the rotation element that fits within the existing plug connection system. This combining approach allows rotational adjustment capability to be added while maintaining compatibility with the existing modular structure, minimizing the increase in overall device complexity.
Solution Approach 2:
The rotation element serves multiple functions: it acts as a structural component of the shaft, provides the rotation adjustment mechanism, and offers a access point for actuation. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity while adding rotational adjustment capability.
Data Source
AI summary
The invention relates to an endoprosthesis shaft system for elongate bones, comprising an anchoring part and a shaft, which is formed from module elements that can be coupled by means of a plug-in connection, wherein a mutual rotation of the elements along the shaft is adjustable and is blocked by means of an anti-rotation mechanism. In order to adjust the rotation, a rotation piece is provided as a further module element, which has a self-contained rotation adjustment device and a clamping device as a mechanism for blocking the rotation. The rotation piece comprises two end faces for the plug-in connection and a sleeve. The invention provides, with the rotation piece, a particular module element for the shaft, which as a structural unit allows both an adjustment of the rotation and a blocking against undesired rotation in a self-contained unit.