Spinal Rod Insertion Kit Using Extension Tube Templates
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Solution Overview
Problem
Minimally invasive spinal fixation procedures face challenges in guiding spinal fixation rods due to the difficulty in navigating rods through small incisions and beneath tissue, especially when pedicle screws have different heights and medial-lateral positions, making it hard to determine the proper length and curvature of the rod.
Innovation Solution
A kit comprising tube connectors, rod templates, and a rod guidance instrument with a guide member that mimics the movement of the spinal fixation rod, allowing for precise visualization and alignment of the rod path through the use of visual guides and channel markers, enabling accurate insertion even in non-linear configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual insertion approach with tactile feedback is used, then the surgeon can guide the rod, but it is extremely difficult to accurately determine the proper length and curvature for the rod
Solution Approach 1:
The patent uses extension tubes as physical copies or representations of the actual rod receiving components. These extension tubes replicate the positions, orientations, and spatial relationships of the implanted pedicle screws, allowing the surgeon to plan and measure rod length and curvature externally where measurements can be accurately made, rather than attempting to measure through tissue.
Solution Approach 2:
The extension tubes serve as intermediary objects between the surgeon and the actual implants. By working with these external proxies, the surgeon can accurately determine rod specifications without directly manipulating or measuring the buried implants, thus resolving the measurement precision problem while maintaining ease of operation.
2Ease of operation
If extensions connected to the implants are used to assist in inserting the rod, then rod insertion is facilitated, but these mechanical approaches typically do not work in multi-level cases where the heights of the implants and/or medial-lateral positions are substantially offset
Solution Approach 1:
The system divides the rod insertion challenge into manageable segments by using individual extension tubes for each pedicle screw level. Each extension tube can be independently positioned and oriented to match its corresponding implant, allowing the system to accommodate multi-level cases with substantial offsets in height and medial-lateral positions that would be impossible with a single rigid mechanical approach.
Solution Approach 2:
The extension tubes are designed to be flexible and adjustable, allowing them to be positioned at various heights and angles to match the specific configuration of pedicle screws in multi-level cases. This dynamic adaptability enables the system to handle substantially offset implant positions while still providing effective rod insertion assistance.
3Ease of manufacture
If minimally invasive procedures are used, then incision size is reduced, but the rod receiving components are not visible beneath the incisions making rod insertion very challenging
Solution Approach 1:
The extension tubes act as intermediary objects that bridge the gap between the small incision and the buried rod receiving components. By attaching extension tubes to the implants through the small incision and extending them outward to visible positions, the surgeon gains external access points and visual references for rod insertion while maintaining the benefits of minimally invasive incisions.
Solution Approach 2:
The system solves the visibility problem by transitioning from a two-dimensional surface view (where implants are hidden beneath skin) to a three-dimensional solution. Extension tubes project the position and orientation information of buried implants into external space, creating visible spatial references that guide rod insertion without requiring larger incisions for direct visualization.
Data Source
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AI summary
Instruments and methods for inserting a spinal fixation rod include various components for inserting a rod with visual guidance. One kit includes a plurality of hollow elongated extension tubes and rod templates. The tube connectors connect the extension tubes in series. Another kit includes a rod guidance instrument having a sleeve. A guide member is attachable to the midsection of the sleeve, and a spinal fixation rod is attachable to the distal end of the sleeve. A method for inserting a spinal fixation rod into a plurality of rod receiving implants includes the steps of contouring a fixation rod to conform to a predetermined shape, contouring a guide member to match the shape of the contoured rod, and guiding the fixation rod into a rod receiving implant by maneuvering the guide member through a guide slot representing the location of the rod receiving implant.