Orthopedic Spring Hinge With Nested Coils Against Shear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional orthopedic hinges, such as mechanical pin hinges and springs, fail to provide sufficient stability and adaptability to the dynamic anatomical axis of rotation, leading to unwanted translational or shearing movements during joint movement, which can cause pain, discomfort, and damage to the joint.
Innovation Solution
A spring hinge with a primary coil spring having a helical structure and a central cavity, featuring nested convex and concave profiles to resist shearing movement, and optionally a secondary coil spring to stabilize the primary coil spring, allowing for pivotal movement while preventing unwanted translational or shearing movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mechanical pin hinge is used to connect external fixators, then the hinge provides a fixed axis of rotation, but it cannot dynamically adapt to the shifting anatomical axis of rotation during joint movement, leading to misalignment and potential joint damage
Solution Approach 1:
The patent employs a spring-based hinge mechanism that dynamically adjusts its axis of rotation to match the anatomical joint's movement. The spring allows the hinge to transition from a static fixed-axis mechanism to a dynamic system that adapts to the shifting anatomical axis during joint motion, resolving the contradiction between adaptability and stability.
Solution Approach 2:
The spring hinge changes its geometric parameters (axis position and orientation) in response to joint movement. As the joint moves and the anatomical axis shifts, the spring deforms and repositions the hinge axis accordingly, allowing the system to maintain alignment with the anatomical axis while preserving rotational stability through the spring's controlled elasticity.
2Adaptability or versatility
If a spring is used as a hinge to allow dynamic adjustment, then the hinge can adapt to anatomical movement, but it exhibits relatively higher instability and allows unwanted translational or shearing movement
Solution Approach 1:
The spring hinge is segmented into multiple functional components: the spring element for dynamic adjustment, the barrel for guiding motion, the plug for maintaining position, and the cotter pin for securing the assembly. This segmentation allows each component to address specific requirements - the spring provides adaptability while the other components collectively provide stability against translational and shearing movements.
Solution Approach 2:
The barrel and plug act as intermediary elements between the spring and the external fixators. These intermediaries constrain the spring's movement to primarily rotational motion while preventing unwanted translational and shearing movements, thus mediating between the spring's dynamic adjustment capability and the stability requirements of the orthopedic application.
3Ease of operation
If a mechanical pin hinge is used, then the hinge structure is simple and stable, but it cannot conform to the dynamic anatomical axis, causing pain and discomfort during joint pivoting
Solution Approach 1:
The spring hinge introduces dynamic behavior to the otherwise simple mechanical pin hinge structure. The spring allows the hinge to adapt its position and orientation during joint movement, conforming to the dynamic anatomical axis and eliminating pain and discomfort, while adding only moderate complexity to the basic pin hinge design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The spring hinge provides stable and controlled pivotal movement about anatomical joints, dynamically adapting to the shifting anatomical axis of rotation, thereby reducing the risk of injury and enhancing the healing process.
Implementation Method 1
a primary coil spring having a helical structure with a central cavity... allowing for pivotal movement about an anatomical joint while substantially or completely preventing unwanted translational or shearing movement
Implementation Method 2
a first surface having a convex profile in a first direction and a second surface having a concave profile in a second direction opposite to the first direction, wherein a portion of the first surface with the convex profile is configured to nest against an adjacent portion of the second surface with the concave profile... and wherein the nested convex and concave profiles resist a shearing movement between the first surface and the second surface
Data Source
AI summary
A device, kit, and method for the treatment of anatomical joint dysfunctions, and more particularly, to a spring hinge comprising: a primary coil spring having a helical structure with a central cavity, wherein the primary coil spring forms a plurality of spirals layered against one another when the primary coil spring is in an unexpanded state; wherein the primary coil spring comprises surfaces that are configured to nest against each other to resist translational or shearing movement between adjoining spiral layers.