Spinal Fusion Cage Cam Locking for Anchor Backout Prevention
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Solution Overview
Problem
Existing spinal fixation devices face challenges in providing sufficient structural integrity and stability during the fusion process, as they may degrade or deform under stress, and lack secure anchoring mechanisms that prevent displacement over time.
Innovation Solution
A cam mechanism is integrated into the orthopedic fusion system, which locks bone anchors in place using a washer, cam, and nut configuration, allowing for simultaneous deployment and secure anchoring of anchors within channels in the cage, enhancing stability and preventing backout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional fixation devices are used to stabilize spinal segments, then initial stability is provided, but long-term stability and prevention of anchor backout are compromised
Solution Approach 1:
The cam mechanism transitions from an unlocked to a locked position, dynamically changing the state of anchor retention. The cam's rotational movement transforms the anchoring system from a loose fit to a mechanically locked configuration, providing progressive stability enhancement as the device is activated
Solution Approach 2:
The fixation device is divided into distinct functional components: the cage structure, the anchor elements, and the cam locking mechanism. This segmentation allows each component to perform its specific function independently, with the cam mechanism specifically dedicated to preventing anchor backout while the cage provides structural support
2Reliability
If robust fixation systems are used to ensure long-term stability, then anchor security is improved, but device complexity increases
Solution Approach 1:
The cam mechanism serves as an intermediary element that mediates between the anchor and the cage structure. Rather than directly threading or welding the anchor to the cage, the cam acts as a mechanical mediator that can be rotated into place to lock the anchor securely, simplifying the overall assembly process while maintaining strong fixation
3Strength
If the spacer maintains structural integrity during fusion, then space stabilization is achieved, but the risk of implant degradation remains
Solution Approach 1:
The spacer is constructed from PEEK (polyether ether ketone), a high-performance polymer composite material that combines excellent mechanical strength, radiolucency, and biocompatibility. This composite material provides sufficient structural integrity to maintain disc space height while resisting degradation from physiological environments and mechanical loading over time
Data Source
AI summary
An embodiment includes an orthopedic fusion system comprising: a cage; a curved first channel coupling a lateral wall of the cage to a superior surface of the cage; a curved second channel coupling the lateral wall of the cage to an inferior surface of the cage; a third channel coupling the superior surface of the cage to the inferior surface of the cage; a curved first anchor configured to slide within the first channel; a curved second anchor configured to slide within the second channel; and a threaded projection extending outwardly from the lateral wall; a washer non-threadingly attached to the threaded projection; a cam non-threadingly attached to the threaded projection and directly contacting the washer; a nut threadingly attached to the threaded projection and directly contacting the cam.