Orthopedic Screw Extension With Independent Height Locking
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Solution Overview
Problem
Existing orthopedic screw extensions for spinal implants are unable to adjust height independently of the screw, necessitating rotation, and lack a secure connection mechanism to rods, compromising biomechanical stability.
Innovation Solution
An orthopedic screw extension with a body featuring a top and bottom portion, including threaded surfaces and side openings, allows for independent height adjustment and secure locking to pedicle screws, facilitating connection to spinal rods through a locking mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the threaded portion of the extension is used to connect to the screw, then the extension can be attached to the screw, but the extension cannot thread into the screw without rotating the extension on top of the screw
Solution Approach 1:
The connection mechanism is divided into two separate functions: a threaded portion for attaching to the screw and a separate locking mechanism with locking arms that engage with the screw head. This segmentation allows the extension to be attached without rotation while providing secure locking.
Solution Approach 2:
The locking mechanism acts as an intermediary between the extension and the screw head, providing a secure connection without requiring the extension to rotate. The locking arms engage with the screw head to prevent rotation while allowing the threaded portion to attach easily.
2Adaptability or versatility
If the extension height is adjusted independently, then the tulip height can be modified to distribute biomechanical load, but existing extensions cannot lock to the screw independently of the height adjuster
Solution Approach 1:
The extension is divided into independent functional components: a height adjustment mechanism and a separate locking mechanism. The locking mechanism includes locking arms that can engage with the screw head independently, providing reliable locking while allowing height adjustment.
Solution Approach 2:
The extension incorporates dynamic elements that allow the height to be adjusted during the procedure while maintaining secure locking. The locking mechanism remains engaged with the screw head regardless of height adjustment, providing continuous stability.
3Strength
If the extension is designed to connect to both the screw and rod, then the biomechanical load can be distributed, but the connection mechanism becomes more complex
Solution Approach 1:
The connection mechanism is segmented into distinct functions: a threaded portion for screw attachment, locking arms for securing the screw head, and side openings for rod insertion. This segmentation achieves multi-component connection without excessive complexity.
Solution Approach 2:
Multiple connection functions are merged into a single extension body that integrates screw attachment, locking, and rod connection capabilities. The locking arms and side openings are combined in one structure that provides both screw and rod connection simultaneously.
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 extension provides adjustable height and secure locking, distributing biomechanical load effectively, enhancing the stability and strength of the implanted system.
Implementation Method 1
The internal surface of the top cavity can include a connection surface such as, but not limited to, a threaded surface
Implementation Method 2
a locking device can be inserted into the top opening in the top cavity and connected thereto (e.g., the locking screw can be threaded on the threaded surface in the cavity of the top portion, etc.) to secure and lock the rod in position relative to the body of the orthopedic screw extension
Data Source
AI summary
An orthopedic screw extension for use in spinal implant applications.