Spinal Fusion Cage with Curved Tip and Perforations
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Solution Overview
Problem
Existing cages for spinal interbody fusion face challenges in durability and bone fusion efficiency due to a simple planar anterior design and perpendicular perforations, leading to inadequate fusion at the anterior portion and reduced bone growth.
Innovation Solution
A cage with a curved tip part and strategically positioned perforations on the side surfaces, allowing for increased bone exposure and stability, and a porous structure to enhance fusion and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the anterior part of the cage body is formed in a simple planar shape, then the manufacturing is simple, but bones are not fused with each other at the anterior portion of the disk
Solution Approach 1:
The anterior part of the cage body is formed with a curved surface having a radius of curvature of 5-15mm instead of a simple planar shape. This curvature allows the cage to conform to the natural anatomy of the anterior disk region, increasing the contact area with adjacent vertebrae and promoting bone fusion while maintaining manufacturing feasibility through standard forming processes.
2Productivity
If the ratio of the perforated portion is large, then the bone growth rate is increased, but the durability is deteriorated
Solution Approach 1:
Perforations are strategically positioned at specific locations on the cage body where they provide maximum benefit for bone ingrowth while minimizing impact on structural strength. The perforations are concentrated in regions that experience lower mechanical stresses, allowing high porosity locally for bone growth while maintaining overall cage durability.
Solution Approach 2:
The cage incorporates a porous structure with controlled porosity to facilitate bone ingrowth. The porous material provides a large surface area for osteoblast attachment and bone tissue infiltration, accelerating bone fusion while the interconnected pore structure distributes mechanical loads effectively, maintaining structural integrity.
3Ease of manufacture
If the inner surfaces of perforated portions are formed perpendicularly to the outer surface, then the manufacturing is simple, but both durability and bone growth rate are reduced
Solution Approach 1:
The inner surfaces of the perforated portions are formed with a curved surface having a radius of curvature of 2-10mm instead of perpendicular to the outer surface. This curved configuration increases the surface area available for bone contact and provides a more favorable geometry for bone ingrowth, while also improving stress distribution to enhance durability. The curved surfaces can be manufactured using standard CNC machining or forming processes.
Data Source
AI summary
One embodiment of the present invention provides a cage for spinal interbody fusion, which has sufficient durability and allows for bone fusion with a bone implanted to the anterior disk as well as fusion between vertebrae, thereby achieving a more stable bone fusion. The cage for spinal interbody fusion according to the embodiment of the present invention comprises a cage body and a tip which is formed to extend from the cage body and have a predetermined curvature. Further, the cage body has a cavity part which is formed to penetrate from the top surface to the bottom surface of the cage body with a projection part having a plurality of projections formed on the top surface and the bottom surface, and at least one perforation part, which is perforated from the side surface adjacent to the top surface or the bottom surface to the direction of the cavity part, and is located in the anterior direction of the cavity part.