Fracture Reduction Assembly with Cam Mechanism
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Solution Overview
Problem
Current methods for reducing skeletal fractures lack controlled and accurate alignment and compression, often leading to non-compressed bone locking and stress on implant components, which can result in deformation and hinder optimal screw placement.
Innovation Solution
A fracture reducing assembly comprising an implant, a buttress, and a reducer with a cam mechanism or compression screw, allowing controlled force application to align and compress bone fragments without compromising the implant's integrity, enabling multiple locking devices in optimal regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a back-slap method is used to reduce the fracture, then reduction may occur, but the reduction is not controlled and there is no instrument to hold compression
Solution Approach 1:
A drill guide is introduced as an intermediary device between the surgeon's hand and the bone fragments. The drill guide provides a structured interface that enables controlled application of reduction force while maintaining compression, replacing the uncontrolled back-slap method with a mediated, instrument-assisted process.
Solution Approach 2:
The drill guide is designed to self-align with the implant through engagement features such as slots or openings. Once positioned, the drill guide maintains compression automatically through its structural design, eliminating the need for continuous manual intervention to hold the compressed state during locking.
2Manufacturing precision
If an implant with a slot and compression screw is used, then control and compression holding are achieved, but the bone screw may flex and deform
Solution Approach 1:
The drill guide acts as a mediator that distributes the compression force across multiple contact points with the bone fragments and implant, rather than concentrating all force on the bone screw. This force distribution prevents excessive loading and potential deformation of the bone screw while maintaining precise reduction control.
Solution Approach 2:
The drill guide is designed to pre-establish the compressed state of the fracture before the bone screw is fully tightened. By maintaining compression during the entire locking process, the system ensures that the bone screw locks the fragments in the correct position without bearing excessive dynamic loads that could cause flexing or deformation.
3Manufacturing precision
If compression screw and slot occupy the same area, then control is achieved, but additional screws cannot be placed in optimal region
Solution Approach 1:
The drill guide introduces a spatial dimension to the reduction process by extending beyond the implant surface in the direction perpendicular to the implant. This allows the compression mechanism to operate in three-dimensional space rather than being constrained to the two-dimensional surface of the implant, freeing up optimal regions on the implant for additional screw placement.
Solution Approach 2:
The drill guide separates the compression function from the screw placement function by providing dedicated engagement features at different locations. The compression is achieved through engagement with the implant at one location, while additional screws can be placed at other optimal locations on the implant without interfering with the compression mechanism.
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 assembly facilitates precise and efficient fracture reduction and compression, maintaining bone fragments in a stable state post-reduction, reducing the risk of implant deformation and allowing for optimal screw placement.
Implementation Method 1
a cam mechanism, wherein the cam mechanism, when activated, applies a force on the buttress to move the second bone fragment towards the first bone fragment
Implementation Method 2
a compression screw, wherein the compression screw, when activated, applies a force on the buttress to move the second bone fragment towards the first bone fragment
Data Source
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AI summary
A controlled removable fracture-reducing assembly (10) for reducing a bone fracture. According to one embodiment of the present invention, a controlled removable fracture reducing assembly (10) includes an implant (12), a reducer (14), a buttress (16), and a locking device (18) that engage a proximal bone fragment (2) and a distal bone fragment (4). The implant (12) is secured to the distal bone fragment (4) by the locking device (18). The buttress (16) engages the implant (12) through an opening (30). The reducer (14) contains a compressing screw (24) that applies a force (60) on the buttress (16), reducing the fracture. According to another embodiment of the invention, the reducer (114) contains a cam mechanism (124) which applies a force (186) on the buttress (116), which does not engage the implant (112), that pushes the proximal bone fragment (102) to reduce the fracture. According to another embodiment of the invention, the reducer (214) is a jacking mechanism that pushes the proximal bone fragment (202) while pulling the implant (212) and distal fragment (204) to reduce the fracture.