Universal Bone Anchoring Device for Multi-Diameter Rods
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Solution Overview
Problem
Current bone anchoring devices require separate versions for different rod diameters, increasing surgical complexity and costs, as they cannot accommodate the range of diameters needed for various spinal regions effectively.
Innovation Solution
A bone anchoring device with a recess design that allows for secure clamping of rods with varying diameters through a multi-point contact system, independent of the rod's diameter, using a V-shaped base and internal threading for stable fixation, enabling use with rods of different diameters from 3 mm to 6.35 mm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate bone anchoring devices are provided for each rod diameter, then the rod can be securely anchored, but the number of device types increases and costs increase
Solution Approach 1:
The bone anchoring device is designed with a universal recess that can accommodate multiple rod diameters (3mm to 6.35mm) through a single device type. The recess geometry and clamping mechanism are configured to adapt to different rod sizes while maintaining secure anchoring, eliminating the need for multiple specialized device variants.
Solution Approach 2:
The device utilizes adjustable clamping parameters through the clamping element that can be configured to exert appropriate force for different rod diameters. The recess dimensions and clamping element geometry are designed to accommodate parameter variations in rod size while maintaining functional performance across the range.
2Device complexity
If a single recess size is used for all rod diameters, then device complexity is reduced, but the clamping security decreases for specific diameters
Solution Approach 1:
The clamping mechanism incorporates a dynamic clamping element that can be adjusted to accommodate different rod diameters within the recess. The clamping element's position and orientation can be modified to optimize contact and force distribution for each specific rod size, maintaining secure clamping despite the universal recess design.
Solution Approach 2:
The clamping function is divided into multiple contact points within the recess, with the clamping element creating distributed force application across the rod surface. This segmented approach to clamping ensures reliable fixation for various rod diameters by creating multiple stable contact zones rather than relying on a single fixed geometry.
3Reliability
If multiple bone anchoring device types are available for different rod diameters, then each rod diameter can be optimized, but surgical complexity increases
Solution Approach 1:
The bone anchoring device incorporates a universal recess design that can receive and securely clamp rods of various diameters (3mm to 6.35mm) using the same device type. This eliminates the need for surgeons to select from multiple specialized device variants, simplifying the surgical workflow while maintaining optimized clamping performance across different rod sizes.
4Adaptability or versatility
If tolerance for rod diameter variation is increased, then different diameter rods can be used, but manufacturing precision requirements are compromised
Solution Approach 1:
The recess is designed with specific dimensional parameters and geometric features that accommodate rod diameter variations from 3mm to 6.35mm. The clamping element and recess geometry are configured to maintain appropriate clearance and contact characteristics across the full range of rod diameters, allowing versatile application without requiring tight manufacturing tolerances on the recess dimensions.
Data Source
AI summary
An anchoring device for anchoring a rod in a bone or a vertebra and for use with at least two rods having a different diameter is provided. The anchoring device includes a shaft and a head for connection to one of said rods. The head is connected to said shaft and has a recess with a base and two substantially vertically extending legs defining a channel for receiving the rod in said channel. The anchoring device further includes a fixation element for clamping said rod in said channel. The fixation element and said base each have a contact surface contacting said rod, the contact surfaces being shaped so as to be able to clamp any of the different rods.