Orthopedic Broach Spring Stop Mechanism Prevents Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopedic broach designs that rely on a spring mechanism for coupling the broach to the handle often experience decoupling issues during excessive force applications, such as during the removal of the broach from a patient's intramedullary canal, leading to potential loss of the broach within the canal.
Innovation Solution
Incorporating a spring stop mechanism within the handle that prevents further deflection of the spring, thereby maintaining increased resistance and ensuring the broach remains securely coupled to the handle, even under high extraction forces, by limiting the spring's flexion and maintaining the latch in an engaged position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring mechanism is used to couple the broach to the handle, then the broach can be easily inserted and removed, but the coupling may fail under excessive extraction forces
Solution Approach 1:
The coupling mechanism transitions from a static spring-based system to a dynamic ratchet-and-pawl system that adapts its resistance based on the direction of force. During insertion, the pawl slides freely along the inclined surface of the ratchet, allowing easy movement. During extraction, the pawl engages with the ratchet teeth, creating progressive resistance that prevents decoupling under excessive forces.
Solution Approach 2:
The coupling mechanism is divided into distinct functional components: the ratchet wheel with multiple teeth, the pawl with engagement and release features, and the spring-loaded actuator. This segmentation allows each component to perform its specific function optimally while working together to solve the contradiction between ease of operation and reliability.
2Productivity
If excessive force is applied to remove the broach during extraction, then the broach can be removed from the intramedullary canal, but the broach may decouple from the handle
Solution Approach 1:
The ratchet mechanism provides preliminary anti-action by creating progressive resistance before excessive force can cause decoupling. As extraction force is applied, the pawl sequentially engages with successive ratchet teeth, building up resistance that prevents the broach from being pulled free while still allowing controlled removal when necessary.
Solution Approach 2:
The spring-loaded pawl actuator provides beforehand cushioning by absorbing extraction forces through elastic deformation. The spring compresses as the pawl engages ratchet teeth, cushioning the impact and distributed the force over time, preventing sudden decoupling while allowing controlled extraction.
3Strength
If the spring deflection is allowed to increase, then the latch can engage more securely, but the spring may become worn and lose resistance over time
Solution Approach 1:
The system transitions from relying on spring deflection strength to a mechanical ratchet engagement system. The pawl engages with rigid ratchet teeth, providing secure latch engagement that does not depend on spring elasticity. This eliminates the wear issue while maintaining strong engagement.
Solution Approach 2:
The spring-based elastic retention system is replaced with a mechanical ratchet-and-pawl engagement system. The ratchet teeth and pawl provide positive mechanical engagement that is independent of spring condition, eliminating the trade-off between engagement strength and spring durability.
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 effectively prevents decoupling of the broach from the handle during removal, providing enhanced stability and security against accidental release, ensuring the broach remains attached throughout the extraction process.
Implementation Method 1
The spring couples the lever to the latch. In one embodiment, the spring includes first and second ends, the first end is arranged and configured to couple to the lever
Implementation Method 2
the spring is prevented from further deflection... by limiting the spring's flexion
Data Source
AI summary
An orthopedic broach is disclosed. The orthopedic broach includes a cutting tip and a broach handle. The broach handle includes a lever, a spring, and a latch. The lever is movably coupled to the handle and to an end of the spring. The latch is movably coupled to the handle and the opposite end of the spring. In use, the lever is movable from an opened position, where the latch is positioned in a released position, so that the cutting tip can be inserted into the handle, to a closed position where the latch is moved to an engaged position wherein the cutting tip is securely coupled to the latch, and thus the handle. The handle includes a spring stop to prevent the spring from further deflection to prevent the latch from moving to the released position and thus prevent decoupling of the cutting tip when excessive forces are applied.