Orthopedic Fixation System With Compression Insert
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopedic fixation systems relying on shape memory implants require shape changes to apply continuous force, which may not be suitable for procedures like patella repair where a constant force is needed without shape alteration.
Innovation Solution
An orthopedic fixation system featuring a compression insert that transitions between natural and insertion shapes, storing energy in the insertion shape and releasing it to affix bones without changing shape, used in conjunction with plates that secure bones in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If shape memory implants are used to apply continuous force, then the fixation force is continuously applied, but the implant must undergo shape change which is not suitable for all procedures
Solution Approach 1:
The system divides the force application function between the compression insert (which changes shape to store/release energy) and the orthopedic implant (which maintains its shape and provides stable fixation). The compression insert is segmented from the main implant structure, allowing it to undergo shape changes independently while the plates and screws maintain their structural integrity and geometric stability for reliable bone fixation.
Solution Approach 2:
The compression insert acts as an intermediary component that mediates between the need for continuous force application and the requirement for shape stability. It stores mechanical energy through shape change and releases it to apply continuous compression force to the bone, while the orthopedic implant itself remains shape-stable and does not undergo deformation, thus resolving the contradiction.
2Ease of operation
If thermally activated shape memory implants are used, then no constraining instrument is needed, but mechanical constraint is often added to prevent premature activation
Solution Approach 1:
The patent extracts the constraining instrument function from the implant itself by using a separate, removable constraining device that is only present during insertion and activation. After the compression insert is activated and begins applying force, the constraining instrument is removed, leaving a simple implant structure without built-in complex constraint mechanisms. This separates the activation control function from the fixation function.
Solution Approach 2:
The constraining instrument is used preliminarily during the insertion and activation phase to prevent premature shape change and control the timing of force application. Once the compression insert is properly positioned and activated, the constraint is removed, and the implant functions independently without requiring ongoing mechanical constraint, thus achieving simple operation after initial setup.
3Reliability
If mechanical constraint is used to prevent premature activation, then activation control is improved, but the system becomes more complex
Solution Approach 1:
The system transitions from a static constraint mechanism to a dynamic one. The constraining instrument is temporary and removable, allowing the system to adapt its complexity: highly constrained during insertion for reliable activation control, then simplified after activation when the constraint is removed. This dynamic approach to constraint management improves activation reliability without permanently increasing device complexity.
Solution Approach 2:
The constraining instrument is discarded after serving its purpose of controlling activation timing. It is removed after the compression insert is activated and begins applying force, leaving only the essential fixation components. This temporary use of constraint instrumentation achieves reliable activation control while avoiding permanent complexity in the final implant configuration.
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
Enables continuous force application to bones without shape change, enhancing fixation and healing by maintaining bone alignment and promoting fusion.
Implementation Method 1
A shape memory implant that requires mechanical constraint stores mechanical energy due to elastic (recoverable) deformation, and then releases the stored mechanical energy when the constraining instrument is removed
Implementation Method 2
shape memory implants typically are composed of a shape memory material such as Nitinol that allows a shape memory implant to have a first final shape and the ability to transition into a second shape
Data Source
AI summary
An orthopedic fixation system includes an orthopedic implant and a compression insert transitionable between a natural shape and an insertion shape. The orthopedic implant includes first and second plates with insert slots configured to receive therein a portion of the compression insert. The first and second plates secure with a bone in an opposed relationship while being separated by an expansion whereby the insert slots of the first and second plates align across the expansion. The compression insert, in the insertion shape, inserts into the insert slots of the first and second plates such that the compression insert spans the expansion. The compression insert, due to an attempted transition thereof from the insertion shape to the natural shape, delivers energy stored therein to the first plate and the second plate whereby the orthopedic implant affixes the bone.