Adjustable Spinal Fusion Cage for Stable Low-Height Insertion
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Solution Overview
Problem
Conventional spinal fusion cages are not adjustable in height, requiring multiple products to accommodate varying patient anatomies, and often lack stability during insertion and use, leading to potential movement and complications.
Innovation Solution
A spinal fusion cage design featuring adjustable endplates with moving blocks and guide units that allow for height adjustment and stable support of vertebral bodies, using a rotating adjusting member to control the distance between endplates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional fixed-height spinal fusion cages are used, then manufacturing and inventory management become complex due to needing multiple sizes, but the cages cannot accommodate varying patient anatomies effectively
Solution Approach 1:
The cage incorporates adjustable height mechanism with movable endplates that can be positioned at different heights after insertion, transforming a static fixed-height structure into a dynamic adjustable structure. This allows a single cage design to accommodate multiple patient anatomies by adjusting the height to match the specific intervertebral space required.
Solution Approach 2:
The adjustable height mechanism enables a single cage model to perform multiple functions by accommodating different intervertebral space heights. Instead of requiring separate cage designs for each height specification, one universal cage design can serve multiple clinical scenarios through post-insertion height adjustment.
2Reliability
If conventional spinal fusion cages are inserted, then the surgery can be performed, but the cages lack stability during insertion and use leading to potential movement and complications
Solution Approach 1:
The cage is designed to be inserted at its lowest height position, and the height adjustment is performed after insertion. This preliminary action of inserting at minimum height ensures stable initial placement, and subsequent height adjustment is done in a controlled manner once the cage is securely positioned between the vertebral bodies.
Solution Approach 2:
The adjustable height mechanism allows the cage to adapt its height after insertion rather than requiring precise pre-setting. This dynamic adjustment capability provides stability during the critical insertion phase, then allows optimization of height post-insertion to ensure proper fit and stability during use.
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 design enables a single cage to accommodate various patient spacings, reducing production and inventory needs while ensuring stable insertion and support, minimizing surgical complications.
Implementation Method 1
an adjusting member (180, 280) which is rotatably mounted in the proximal moving block (170, 270) and screwed with the distal moving block (140, 240), so as to adjust a distance between the distal moving block (140, 240) and the proximal moving block (170, 270)
Data Source
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AI summary
The present invention provides a spinal fusion cage that can be inserted between vertebral bodies at the lowest height, and the height thereof may be adjusted with being inserted, such that cages having different heights within a certain range may be replaced by one cage. Therefore, the number of product groups that should be produced is reduced and the amount in stock is also decreased on the manufacturer. In addition, unlike the cage having a predetermined height at a constant interval in the prior art, the height of the spinal fusion cage is linearly adjusted according to a spacing between vertebral bodies of a patient, such that the surgery may be performed at the optimal height according to spinal conditions of the patient.