Superelastic Compression Device for Cyclic Fracture Loading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing orthopedic implants, such as washers and bone plates, fail to maintain consistent compression at bone fracture sites due to cyclic loading, leading to gap formation and interference with the healing process, and involve complex surgical procedures with numerous separate parts.
Innovation Solution
A compression device made of superelastic material, which exerts a biasing force along the axis of a fastener to maintain compression, and a bone plate assembly with an integral compression structure that reduces the number of implantable parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If traditional washers and bone plates are used to distribute load, then stress on bone is reduced, but compression at fracture sites deteriorates due to cyclic loading
Solution Approach 1:
The patent changes the material parameter from traditional elastic materials to superelastic material, which exhibits nonlinear stress-strain behavior and hysteresis. This allows the compression device to maintain compressive force at the fracture site throughout the loading cycle while still distributing load on the bone, resolving the contradiction between stress distribution and compression maintenance.
Solution Approach 2:
The invention uses composite construction by integrating the compression device with the bone plate structure. The bone plate includes a superelastic material layer that provides both load distribution and compression maintenance functions simultaneously, combining the benefits of stress distribution and reliable compression at the fracture site.
2Reliability
If numerous separate implantable parts are used, then compression and load distribution functions are provided, but surgical procedure complexity increases
Solution Approach 1:
The patent merges the compression device and bone plate into a single integrated implantable assembly. The bone plate includes an integrated superelastic material that provides both compression function and load distribution function, eliminating the need for separate washers and compression devices, thus reducing surgical complexity while maintaining all necessary functions.
Solution Approach 2:
The integrated bone plate assembly performs multiple functions simultaneously: it provides compression at the fracture site, distributes load on the bone, and maintains structural support. This multi-functional design eliminates the need for multiple separate components, reducing the number of implantable parts while maintaining comprehensive functionality.
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 superelastic compression device and bone plate assembly maintain consistent compression during healing, simplifying surgical procedures by reducing the number of implantable parts and enhancing bone fracture healing.
Implementation Method 1
a compression device composed at least in part of a superelastic material positioned between the head of fastener, such as a lag screw, and a bone surface may exert a biasing force in a direction along the axis of the fastener when the compression device is deformed in an opposite direction
Data Source
AI summary
A compression device made of a superelastic material having a peripheral portion with an upper surface, a lower surface, and a central opening extending therethrough is provided. Tips of one or more resilient structures of the compression device project inward of the peripheral portion and form an opening. The one or more resilient structures are configured to exert a biasing force in a direction when deformed in an opposite direction. Also provided is a bone plate assembly comprising a captively retained compression device and a bone plate comprising one or more integrally formed resilient structures.