Articulating Expandable Interbody Implants for No-Distraction Delivery
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Solution Overview
Problem
Conventional intervertebral fusion devices require vertebral body distraction to maintain disc spacing, making installation difficult due to height discrepancies between the distracted space and the device dimensions.
Innovation Solution
An articulating expandable fusion device that can be deployed and expanded within the intervertebral disc space without distraction, utilizing a system of links with ramped surfaces and a cable mechanism to articulate and expand into a polygonal shape, allowing for precise placement and stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fusion devices are used, then spinal stability can be restored, but vertebral body distraction is required which complicates installation due to height discrepancies
Solution Approach 1:
The fusion device incorporates an expandable structure with articulating links that can transition from a compressed delivery configuration to an expanded deployed configuration. This dynamic transformation allows the device to be inserted in a compact form and then expanded in situ to achieve the desired disc space height, eliminating the need for pre-distraction and simplifying installation while maintaining spinal stability
Solution Approach 2:
The device employs a nested structure where the expandable cage is contained within a delivery system during insertion. The articulating links are folded or compressed within the delivery catheter, allowing minimally invasive access to the disc space. Once positioned, the device is deployed and expanded to its functional configuration, enabling easy installation without requiring the device to maintain its final height during insertion
2Length of stationary object
If vertebral body distraction is performed to maintain disc spacing, then normal disc spacing can be achieved, but the device height must be larger than the distraction height making installation difficult
Solution Approach 1:
The device transitions from a compressed state during delivery to an expanded state after implantation. The expandable cage structure allows the device to achieve the required disc spacing height only after insertion, eliminating the contradiction between device height and distraction height. The device is inserted at a smaller profile and then expanded to maintain normal disc spacing
Solution Approach 2:
The fusion device is divided into articulating links that can move relative to each other. This segmentation allows the device to be folded into a compact configuration for delivery and then articulated into an expanded configuration to achieve the desired disc height. The modular link structure enables transformation between compressed and expanded states, facilitating easy installation while maintaining proper disc spacing
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
Facilitates minimally invasive installation and maintains normal disc spacing while providing spinal stability and intervertebral fusion, reducing the risk of implant migration and endplate disruption.
Implementation Method 1
Translation of the middle bodies causes the one or more ramped surfaces of the middle bodies to slide against the one or more ramped surfaces of the upper and lower bodies, thereby resulting in expansion of the expandable implant
Implementation Method 2
a first link, a second link pivotally connected to the first link, and a third link pivotally connected to the second link
Data Source
AI summary
Articulating expandable fusion devices, systems, instruments, and methods thereof. The articulating expandable fusion implant having a plurality of links is capable of being deployed and articulated inside an intervertebral disc space link by link. After the links are articulated into a polygonal shape, the links may be expanded outwardly into an expanded configuration. Instruments may be provided to articulate and expand the implant.