Elbow Fixator Centering Window and Hinge Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current external orthopaedic fixators for elbow joints are inadequate in centering, allow incomplete kinematic movement, and are excessively large and heavy, making them unsuitable for effectively treating flexion contracture and joint rigidity.
Innovation Solution
The design includes a radiotransparent centering window with radiopaque references and a hinging mechanism allowing full kinematic movement, along with adjustable anchoring means and a distraction system to facilitate precise alignment and rehabilitation of the elbow joint, featuring a cylindrical centering window and inclined distraction axis for effective joint distraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If radiopaque fixator components are used, then structural strength and stability are improved, but bone joint visibility and centering precision deteriorate
Solution Approach 1:
The fixator is divided into proximal and distal portions connected by an articulator, allowing modular assembly. The centering window is a separate radiotransparent component that can be precisely positioned between the radiopaque portions, enabling both structural integrity and radiographic visibility without requiring the entire device to be radiotransparent.
Solution Approach 2:
A radiotransparent centering window is introduced as an intermediary element between the radiopaque proximal and distal portions. This window allows X-ray visibility for precise centering while the surrounding radiopaque structure provides the necessary strength. The window acts as a mediator that reconciles the conflicting requirements of visibility and strength.
2Stability of the object's composition
If external fixators are designed to protect the joint, then stability is improved, but kinematic movement capability deteriorates
Solution Approach 1:
The articulator is designed with a hinge mechanism that allows dynamic movement between the proximal and distal portions. The hinge axis can be positioned to match the elbow joint's natural axis of rotation, enabling the fixator to adapt from a static protective structure to a dynamic device that reproduces full kinematic movement including flexion, extension, and rotation.
Solution Approach 2:
The articulator serves multiple functions: it provides structural connection between bone segments, enables controlled movement, and can be configured to reproduce the entire kinematic movement of a healthy elbow joint. This multi-functionality allows the same device to both protect the joint and restore its movement capabilities.
3Adaptability or versatility
If external fixators allow full kinematic movement, then rehabilitation effectiveness is improved, but device complexity and size increase
Solution Approach 1:
The articulator integrates multiple functional elements into a single unified structure: the hinge mechanism, the connection between proximal and distal portions, and the movement control are all combined in one component. This merging reduces the number of separate parts and simplifies the overall device while maintaining full kinematic movement capability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An external orthopaedic fixator (1) for elbow joints comprising: proximal anchoring means (2) intended to be integrally associated to a proximal bone (100) of a patient's upper limb; distal anchoring means (3) intended to be integrally associated to a distal bone (101) of a patient's upper limb; an articulator (4) hinging together said proximal (2) and distal (3) anchoring means along a hinging axis (x), intended to be positioned in correspondence with an elbow joint (102) connecting said proximal (100) and distal (101) bones; said articulator (4) comprising a radiotransparent centering window (40) intended to frame the elbow joint (102) when positioning the external orthopaedic fixator (1), said hinging axis (x) passing through said centering window (40).