Motion Preserving Spinal Implant Composite Core Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spinal implants for degenerative disc disease often limit range of motion and mobility due to metal-to-metal sliding and corrosion, leading to wear and debris issues, and inadequate shock absorption.
Innovation Solution
A motion-preserving spinal implant design featuring a polymeric and elastomeric inner core with varying hardness, surrounded by a polymeric outer core, which reduces wear through non-sliding components and enhances cushioning and shock absorption, while maintaining spinal motion range using specific geometries and materials like silicone or ultra-high molecular weight polyethylene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal-to-metal spinal implant components are used, then structural strength and load-bearing capacity are improved, but wear and corrosion occur leading to debris generation and reduced reliability
Solution Approach 1:
The implant uses a composite structure combining metal end plates for strength with a polymeric elastomeric core for wear resistance. The metal components provide load-bearing capacity while the polymeric core eliminates metal-to-metal contact, preventing wear and corrosion.
Solution Approach 2:
The polymeric elastomeric core acts as an intermediary between the metal end plates, preventing direct metal-to-metal contact. This intermediate layer absorbs wear and corrosion that would otherwise affect the metal components directly.
2Strength
If rigid metal components are used for spinal implant, then load-bearing capacity is improved, but shock absorption and cushioning are reduced
Solution Approach 1:
The patent changes the material parameters from rigid metal to flexible polymeric elastomer for the core components. This allows the implant to maintain load-bearing capacity through the metal end plates while the polymeric core provides shock absorption and cushioning through its elastic properties.
Solution Approach 2:
The composite structure combines rigid metal end plates for load-bearing with flexible polymeric elastomeric core for shock absorption. This material combination allows simultaneous achievement of both load-bearing capacity and cushioning properties.
3Reliability
If spinal fusion treatment is used, then pain relief is achieved, but range of motion and mobility are limited
Solution Approach 1:
The implant is designed as a dynamic motion-preserving device with a flexible polymeric elastomeric core that allows physiological movement. Unlike rigid fusion implants, this dynamic structure accommodates spinal motion while providing pain relief, maintaining both reliability and ease of operation.
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 implant effectively reduces degeneration from metal wear, increases cushioning and shock absorption, and maintains spinal motion range by resisting compression, shear-compression, and torsion forces, thereby providing a more functional and durable solution for degenerative disc disease treatment.
Implementation Method 1
a polymeric and elastomeric inner core with varying hardness, surrounded by a polymeric outer core, which reduces wear through non-sliding components and enhances cushioning and shock absorption
Implementation Method 2
reduces degeneration due to metal wear because of no sliding between metal plates
Data Source
AI summary
A motion preserving spinal implant is presented for use in placement between intervertebral space for total replacement of a degenerated spinal disc. The motion preserving spinal implant has a pair of end plates sandwiched around an inner core and an outer core, with the inner core being concentrically positioned within the outer core. The outer core encapsulates the inner core and provides adequate sealing of the inner core while maintaining flexibility and elasticity to advantageously support physiological movements. The inner core is constructed of an elastomeric material and acts as a solid diaphragm in order to resist and withstand localized compression and other forces. The end plates provide anchoring and fusion with adjoining vertebra and hold the inner and outer cores in place. The motion preserving spinal implant restores the normal height and natural function of the degenerated spinal disc and preserves the natural motion of the spine.