Spinal Implant Polyaxial End Plate Curvature Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spinal implants lack adjustability to match the natural curvature of individual patients' spinal columns, limiting their effectiveness in stabilizing and replacing vertebrae.
Innovation Solution
A polyaxial joint is created through a rotation-symmetric recess in the end plate guided by an annular ridge, allowing the end plate to rotate around different axes, enabling automatic adjustment to the spinal column's curvature and reducing component complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hinge-like connection with pins is used between the body and end plate, then the end plate can be pivoted relative to the body, but the adjustment is limited to a fixed axis of deviation and cannot accommodate individual spinal curvature variations
Solution Approach 1:
The patent applies spheroidality by replacing the traditional pin-based hinge connection with a spherical joint mechanism. The end plate features a spherical recess that receives a spherical projection from the body, enabling multi-axial rotation and pivoting. This spherical geometry allows the end plate to be oriented in multiple directions (polyaxial adjustment) rather than being constrained to a single fixed axis, thereby accommodating various spinal curvatures and implantation angles while maintaining a relatively simple component structure.
2Adaptability or versatility
If multiple implant variants with different angles are provided to match individual spinal curvature, then adjustability is improved, but the number of components increases and storage costs rise
Solution Approach 1:
The patent implements universality through the polyaxial spherical joint design that allows a single implant type to accommodate multiple implantation scenarios. The spherical joint enables the end plate to be positioned at various angles and orientations (typically up to 360 degrees of rotation), making one implant design universally applicable to different spinal curvatures and anatomical variations. This eliminates the need to maintain multiple specialized implant variants in inventory, reducing storage costs and simplifying surgical selection.
3Ease of operation
If pins are used to connect the end plate to the body, then the end plate can be shifted along the pins, but twisting about the longitudinal axis is hindered
Solution Approach 1:
The spherical joint design replaces the linear pin constraint with a spherical geometry that inherently permits rotation about the longitudinal axis. The spherical recess and projection allow the end plate to rotate freely in all directions including twisting motions, while still maintaining stable connection and preventing dislocation. This spherical mechanism provides both ease of positioning during surgery and full rotational adaptability for matching spinal anatomy.
Data Source
AI summary
An implant for use between two axially separated vertebrae has a body extending axially between the vertebrae and having longitudinally outwardly directed ends juxtaposed with the vertebrae and each formed with a radially outwardly projecting annular rounded ridge and with a radially outwardly open groove axially inward of the ridge. A respective end plate at each of ends bears axially outwardly directly on the respective vertebra and is formed with a radially inwardly open rotation-symmetrical recess receiving the respective end of the body. This recess is formed with an annular inwardly open groove having an inner surface on which rides the respective ridge with freedom for swiveling of each end plate on the respective end.