Interbody Spinal Fusion Cage with PEEK Insert and Planar Pins
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current interbody spinal fusion methods face challenges such as graft migration, fracture, and limited biologic environment due to bulky metal expandable cages and the need for separate fixation plates with PEEK cages, which often require additional stabilization.
Innovation Solution
An interbody spinal fusion assembly comprising a metal cage with a PEEK insert, secured by planar metal pins and bone engaging fasteners, providing enhanced stability and biologic environment through precise placement and fixation between vertebras.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fibula strut grafts are used for anterior cervical corpectomies, then fusion can be achieved, but the graft is vulnerable to fracture, dislodgement, displacement, and telescoping
Solution Approach 1:
The interbody cage is divided into two main components: a metal cage structure providing mechanical strength and a PEEK insert providing biologic functionality. This segmentation allows each component to address specific weaknesses - the metal cage prevents fracture and displacement while the PEEK insert promotes bone growth and reduces telescoping
Solution Approach 2:
The invention uses a composite structure combining metal and PEEK materials within a single interbody cage assembly. The metal cage provides the necessary mechanical strength to prevent fracture and displacement, while the PEEK insert offers biologic compatibility and resistance to telescoping, creating a unified device that addresses multiple failure modes simultaneously
2Area of stationary object
If PEEK cages are used for interbody stabilization, then endplate coverage is improved, but the cage tends to move out of position requiring separate fixation plates
Solution Approach 1:
The invention merges the interbody cage and fixation elements into a single integrated assembly. The metal cage structure includes integrated fixation features such as hooks, wings, or lateral extensions that directly engage with the vertebral bodies, eliminating the need for separate fixation plates while maintaining positional stability and comprehensive endplate coverage
3Stability of the object's composition
If metal expandable cages are used for interbody stabilization, then fixation is provided, but the cages are bulky and risk adjacent body fracture
Solution Approach 1:
The metal cage is designed with non-uniform thickness and density distribution, concentrating material where mechanical strength is needed for fixation (such as at the engagement points with vertebral bodies) while reducing material in areas where it would add unnecessary bulk. This localized quality optimization provides stable fixation while minimizing cage volume and adjacent body fracture risk
4Length of moving object
If longer grafts are used for multi-level reconstruction, then more vertebral bodies are covered, but the risk of graft migration, displacement, or fracture increases
Solution Approach 1:
For multi-level reconstructions, the invention allows use of multiple shorter interbody cage assemblies rather than a single long graft or cage. Each cage can be optimally sized for its specific vertebral level, reducing the risk of migration and fracture while collectively covering all required vertebral bodies. The standardized design of each cage facilitates consistent placement and fixation across multiple levels
Data Source
AI summary
An interbody spinal fusion assembly includes an interbody cage, planar metal pins and bone fasteners. The interbody cage includes a metal cage and a PEEK insert. The PEEK insert is inserted into a slot of the metal cage and is secured to the metal cage with a pin. The assembled interbody cage is inserted in the space between two adjacent vertebras and is secured in placed with the planar metal pins and the bone fasteners.