Patellofemoral Trial Extractor with Moveable Arms
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopaedic extraction tools often damage bone and soft tissues due to cumbersome connection methods and high risk of failure under shear loads, requiring osteotomy or cutting, which complicates the insertion and removal of trials and implants.
Innovation Solution
The development of insertion and extraction instruments with moveable arms and engagement features that form a secure, non-rigid connection with implants, utilizing a biasing element and contoured surfaces to facilitate easy engagement and disengagement, reducing the need for cutting and minimizing bone contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If threaded connection methods are used to attach the extractor to the implant, then the connection can be achieved, but the process is time-consuming and the threaded rod may fail under shear loads
Solution Approach 1:
The extractor employs a dynamic connection mechanism where the body can translate along the central axis to engage or disengage arms from apertures. This dynamic engagement allows quick attachment and detachment without threading, resolving the contradiction between connection reliability and time consumption.
Solution Approach 2:
The extractor is segmented into a body and multiple arms that can independently engage with apertures. This segmentation allows the connection to be distributed across multiple points (multiple arms engaging multiple apertures), improving overall connection reliability while maintaining quick engagement through the translation mechanism.
2Ease of operation
If osteotomy or cutting methods are used to remove trials, then the trial can be removed, but there is a risk of damaging the bone periphery, soft tissues, and bone implant site
Solution Approach 1:
The extractor directly extracts the trial or implant from the bone site by engaging with its apertures and applying extraction force. This eliminates the need for osteotomy or cutting methods, thereby removing the harmful effects of bone and soft tissue damage while maintaining effective trial removal capability.
3Device complexity
If a single connection point is used between the extractor and implant, then the structure is simple, but the likelihood of failure under load is higher
Solution Approach 1:
The extractor is divided into a body and multiple arms, each capable of engaging with separate apertures on the implant. This creates multiple connection points distributed across the structure, improving reliability under load without excessive complexity since the arms are simple extensions of the body that translate together.
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 a quick, effective, and secure method for inserting and removing orthopaedic trials and implants, reducing the risk of damage to bone and soft tissues while minimizing the likelihood of tool failure, thus enhancing the efficiency and safety of orthopaedic procedures.
Implementation Method 1
the biasing element is a spring disposed around the boss
Data Source
AI summary
Disclosed herein are insertion and extraction instruments for orthopaedic procedures that are used for inserting and extracting trials and implants. The instruments include a body extending along a central axis having first and second arms extending from the body along first and second axes. The first and second arms may be moveable with the distal ends of the arms being configured to engage first and second engagement feature of a trial or an implant. The first and second axes define an angle therebetween such that when the distal end of the first arm is received in a first engagement feature of the implant and the distal end of the second arm is in the second engagement feature, the distal ends of the arms are urged against respective first and second side walls of the first and second arms to secure the instrument to the trial or implant.