Segmented DRUJ Prosthesis for Adjustable Forearm Rotation
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Solution Overview
Problem
Current prosthetic implants for the distal radioulnar joint (DRUJ) lack flexibility and adaptability to accommodate varying patient anatomy and geometry, limiting their ability to restore natural pronation-supination motion and stability between the ulna and radius.
Innovation Solution
A 3-piece DRUJ prosthesis system comprising a stem component, an ulnar head component, and a set screw, which allows for adjustable alignment and sizing to match individual anatomy, along with an optional sigmoid notch component for articulation with the radius, enabling variable pivoting and rotational alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed-design prosthesis is used, then manufacturing is simpler, but adaptability to varying patient anatomy is reduced
Solution Approach 1:
The prosthesis is divided into multiple components: a base component with a receptacle, a positioning component with protrusion and alignment features, and a fastening mechanism. This segmentation allows independent optimization of each component's geometry to match varying patient anatomies while maintaining overall structural integrity and simplifying manufacturing of individual parts.
Solution Approach 2:
The prosthesis incorporates adjustable alignment features including rotatable positioning components and modular elements that can be configured in different orientations. This dynamic adjustability enables the fixed manufacturing design to adapt to varying patient anatomies post-manufacturing, resolving the contradiction between manufacturing simplicity and anatomical adaptability.
2Reliability
If a single-component prosthesis is used, then device complexity is reduced, but ability to restore natural motion and stability is limited
Solution Approach 1:
The prosthesis is segmented into functionally distinct components: a base component for structural support and articulation, a positioning component for alignment and motion control, and a fastening mechanism for secure attachment. This segmentation enables each component to be optimized for its specific function, thereby restoring natural pronation-supination motion and stability more effectively than a single-component design.
Solution Approach 2:
The positioning component features a protrusion that fits into a receptacle on the base component, creating a nested arrangement. This nesting provides inherent mechanical guidance and constraint that restores natural motion patterns while maintaining compact overall structure, achieving reliable motion restoration without excessive complexity.
3Manufacturing precision
If fixed alignment prosthesis is used, then manufacturing precision requirements are reduced, but ability to match individual anatomy is compromised
Solution Approach 1:
The prosthesis includes rotatable positioning components and adjustable alignment features that can be configured in multiple orientations after implantation. This dynamic adjustability allows the prosthesis to be adapted to individual patient anatomies without requiring extremely high manufacturing precision for pre-set alignment, as the alignment is finalized during surgical assembly rather than during manufacturing.
Solution Approach 2:
The positioning component acts as an intermediary between the base component and the bone, providing adjustable alignment interfaces. This intermediary element absorbs the variability in anatomical requirements, allowing standard manufacturing tolerances to be used while still achieving precise final alignment through intraoperative adjustment of the positioning component's orientation.
Data Source
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AI summary
Disclosed is a distal radio ulnar joint prosthesis system, and the method of use for the same, the system comprising an ulnar stem component, and ulnar head component, a set screw, and a sigmoid notch component, the system providing a prosthesis for replacement of the distal radio ulnar joint to restore the pronation-supination motion of the forearm as well as stability between the ulna and radius; a DRUJ prosthesis adapted for rotational alignment of the replacement joint along the axis of forearm rotation; a DRUJ prosthesis which allows for the use of a number of different sized heads having differing geometries; a DRUJ prosthesis adapted for variable pivoting alignment between the replacement distal ulnar head and the ulna; and a DRUJ prosthesis adapted for adjustment in the alignment between the articulating surface of the ulnar head and the sigmoid notch.