Composite Bone Screw with Radiopaque Marker Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metallic bone screws interfere with medical imaging and radiotherapy, cause stress shielding, and have biocompatibility issues, while non-metallic composite materials may lack sufficient radiopacity and mechanical strength.
Innovation Solution
A fiber-reinforced composite material bone screw with a threaded region and a layer of powdered radiopaque marker material, such as gold or tungsten, distributed circumferentially around the threaded shaft, combined with a metallic outer layer for enhanced strength and reduced imaging artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic bone screws are used, then mechanical strength and stability are improved, but imaging visibility and radiotherapy effectiveness deteriorate
Solution Approach 1:
The bone screw is divided into distinct functional segments: a metallic core providing mechanical strength and a separate radiopaque marker layer providing imaging visibility. This segmentation allows each component to optimize its specific function without compromising the other.
Solution Approach 2:
A radiopaque marker layer acts as an intermediary between the metallic core and the imaging system. This layer provides the necessary radiopacity for imaging while the metallic core maintains mechanical strength, effectively mediating between conflicting requirements.
2Strength
If metallic bone screws are used, then mechanical strength is improved, but stress shielding and biocompatibility deteriorate
Solution Approach 1:
The bone screw uses a composite structure combining metallic core material with radiopaque marker material in a layered configuration. This composite approach allows optimization of mechanical properties while reducing stress shielding effects through the specific material selection and arrangement.
3Object-affected harmful factors
If non-metallic composite materials are used, then imaging visibility and biocompatibility are improved, but radiopacity and mechanical strength deteriorate
Solution Approach 1:
The invention uses a composite structure combining radiopaque marker material with polymer matrix material. This composite approach provides sufficient radiopacity for imaging while maintaining adequate mechanical strength through the fiber-reinforced polymer structure.
Solution Approach 2:
The radiopaque marker material is concentrated in specific regions (threaded portion and tip) where it is most needed for imaging visibility, while the overall structure maintains appropriate mechanical properties through localized reinforcement and material distribution.
4Object-affected harmful factors
If radiopaque marker material is added to composite bone screws, then imaging visibility is improved, but device complexity increases
Solution Approach 1:
The bone screw structure is segmented into distinct functional layers: the fiber-reinforced polymer core providing mechanical strength and the radiopaque marker layer providing imaging visibility. This segmentation allows independent optimization of each function while maintaining overall structural integrity.
Solution Approach 2:
The radiopaque marker material is nested within the polymer matrix material, with the marker layer positioned between the threaded portion and the outer surface. This nested arrangement integrates multiple functions within a unified structure, reducing overall complexity.
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 solution provides improved radiopacity for better imaging visibility, reduced stress shielding, and enhanced mechanical strength, while minimizing interference with medical imaging and radiotherapy, and addressing biocompatibility concerns.
Implementation Method 1
a layer comprising particles of powdered radiopaque marker material distributed within a polymer matrix
Data Source
AI summary
Composite material screws and construction techniques are described comprising reinforcing fibers directed in different winding directions and/or angles at different layers (radial depths) of the screw. Optionally, the screw comprises composite material layers wound with fibers at both the pitch of the thread of the screw and at a steeper pitch (for example, about 45°). Optionally, an outer layer of the screw comprises a relative radiolucent construction and/or material, with a more radiopaque construction and/or material positioned underneath the outer layer such that at least a portion of the screw outline is delineated by a radioimaging technique (for example, fluoroscopy, CT, or MRI), while maintaining a sufficiently artifact-free image around the screw that the image characteristics of the surrounding tissue are still determinable.