Expandable Intervertebral Implant In Situ Adjustment
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Solution Overview
Problem
Current intervertebral disc replacement and fusion devices are fixed in size and shape, requiring open surgery for insertion and distraction instrumentation, which complicates minimally invasive procedures and increases the risk of neural tissue injury and scarring.
Innovation Solution
An expandable intervertebral implant that can be inserted in a collapsed state and expanded in situ, featuring a base body, top and bottom endplates, and a center component with a threaded actuator rod to adjust the endplates' position, allowing for upward or downward expansion without the need for open surgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fixed-size intervertebral implants are used, then the implant structure is simple and easy to manufacture, but open surgery is required for insertion and distraction instrumentation is needed, increasing surgical complexity and risk of neural tissue injury
Solution Approach 1:
The implant transitions from a static fixed-size structure to a dynamic expandable structure. The implant is inserted in a collapsed state through minimally invasive access, then expanded in situ to the desired size using an actuator mechanism, eliminating the need for open surgery and distraction instrumentation while maintaining structural integrity
Solution Approach 2:
The implant components are nested within each other in a collapsed configuration for minimally invasive insertion. The endplates and center component are contained within a compact envelope that can pass through small incisions, then deployed to their full functional configuration after insertion
2Adaptability or versatility
If fixed-size intervertebral implants are used, then the implant design is straightforward, but distraction instrumentation and open surgery are required, increasing the risk of neural tissue injury and scarring
Solution Approach 1:
The implant provides adaptability through dynamic size adjustment after insertion. The actuator mechanism allows the implant to be expanded to various sizes depending on the specific anatomical requirements, while the minimally invasive approach reduces exposure of neural tissues and risk of injury
Solution Approach 2:
The implant is prepared in a collapsed state before insertion, allowing it to pass through small incisions without requiring large open exposures. The expansion to final size occurs after the implant is already in position, minimizing the time neural tissues are exposed and reducing scarring
3Object-affected harmful factors
If expandable intervertebral implants are used, then minimally invasive surgery is enabled with reduced neural tissue injury risk, but the implant structure becomes more complex with additional components
Solution Approach 1:
The implant is divided into distinct functional segments: endplates for load bearing and attachment, a center component for structural support, and an actuator mechanism for size adjustment. This segmentation allows each component to be optimized for its specific function while working together as an integrated system
Solution Approach 2:
The actuator mechanism serves as an intermediary between the surgeon's control and the implant's size adjustment. It translates rotational motion into linear expansion of the implant, providing precise control over the expansion process while protecting the neural tissues from direct exposure to instrumentation
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
Enables minimally invasive surgery by allowing the implant to be inserted through a small incision and expanded within the intervertebral space, reducing the risk of neural tissue injury and scarring while maintaining spinal mobility.
Implementation Method 1
The center component includes a threaded through-opening in a front portion... an actuator rod having an outer threaded surface and being configured to be threaded into the threaded through-opening... Threading the actuator rod into the threaded through-opening moves the center component longitudinally forward
Implementation Method 2
The top endplate includes first and second protrusions having inclined surfaces and extending obliquely downward... Threading the actuator rod into the threaded through-opening moves the center component longitudinally forward into the base body, and causes the inclined surfaces of the first and second protrusions of the top endplate to slide upward onto the inclined surfaces of the first protrusions of the first and second sides of the center component
Data Source
AI summary
An expandable intervertebral implant includes a base body, a top endplate and a center component. The top endplate is configured to be placed onto an open top of the base body and to expand upward. The top endplate includes a plate, first and second side protrusions extending vertically downward from first and second sides of the plate, respectively, first and second protrusions including inclined surfaces and extending obliquely downward from a first end of the plate and third and fourth protrusions having a triangular shape with at least one inclined surface and extending downward from a second end of the plate. The center component is configured to be placed within the base body and to interface with the top endplate and to move longitudinally forward or backward within the base body, thereby causing the top endplate to expand upwards or move downward, respectively.