Expandable Spinal Implant Wedge Mechanism for Lordotic Curvature
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spinal fusion implants lack the ability to effectively restore the natural lordotic curvature of the lumbar spine and provide adequate expansion to accommodate bone growth and graft material.
Innovation Solution
The development of an expandable spinal fusion implant featuring a housing, upper and lower endplates, a translating wedge, and a drive mechanism that allows the implant to be inserted in a collapsed state and expanded to create a lordotic angle, facilitating bone growth and graft placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If existing spinal fusion implants are used, then the implant can be inserted into the disc space, but the implant cannot restore the natural lordotic curvature of the lumbar spine
Solution Approach 1:
The implant incorporates an expandable structure with a translating wedge mechanism that allows the lordotic angle to be adjusted dynamically after insertion. The wedge can translate between proximal and distal positions to change the expansion angle, enabling the implant to adapt to different lordotic curvature requirements while maintaining structural integrity.
Solution Approach 2:
The implant design allows changing the lordotic angle parameter from a fixed value to an adjustable range. By modifying the wedge position and expansion angle, the implant can achieve different lordotic curvatures to match the patient's natural spine anatomy, transforming a static parameter into a variable one.
2Volume of stationary object
If existing spinal fusion implants are used, then the implant can be inserted into the disc space, but the implant cannot provide adequate expansion to accommodate bone growth and graft material
Solution Approach 1:
The implant features a dynamic expansion mechanism where the wedge can translate to adjust the internal volume and expansion angle. This allows the implant to be expanded post-insertion to create adequate space for bone graft material and accommodate bone growth, transforming a static volume into an adjustable one.
Solution Approach 2:
The implant is divided into expandable segments with the wedge mechanism that can translate to increase the internal cavity volume. This segmentation allows the structure to expand and create more space for graft material without requiring a completely different implant size.
3Adaptability or versatility
If an expandable mechanism is added to restore lordotic curvature, then the implant can be expanded after insertion, but the device complexity increases
Solution Approach 1:
The wedge mechanism is integrated within the housing structure, merging the expansion mechanism with the main body of the implant. This consolidation reduces the number of separate components and simplifies the overall device while maintaining the expandable functionality for lordotic curvature adjustment.
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 expandable spinal fusion implant effectively restores the natural lordotic curvature of the lumbar spine, provides sufficient expansion for bone growth and graft placement, and maintains a static housing height throughout the expansion process.
Implementation Method 1
a translating wedge positioned between the upper and lower endplates and within the housing
Data Source
AI summary
An expandable spinal fusion implant including a housing, upper and lower endplates, a wedge positioned within the housing and between the upper and lower endplates and a drive mechanism to urge the wedge distally between the upper and lower endplates to increase the separation between the endplates and expand the overall height of the distal end of the implant.