Spinal Fixation Plate Anti-Backout Locking Mechanism
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Solution Overview
Problem
Current spinal fixation and fusion devices face challenges in preventing screws from backing out after placement, which can lead to instability and complications during spinal surgery.
Innovation Solution
A surgical fixation system and spinal fusion implant assembly featuring a plate with anti-backout elements, comprising a biasing member and a locking slide that deforms elastically to secure anchor elements in place, preventing them from backing out by covering the proximal end of the anchor element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple aperture design is used in the plate, then the device complexity is reduced, but the reliability of preventing anchor element backout deteriorates
Solution Approach 1:
The anti-backout mechanism is segmented into distinct functional components: a locking slide that moves independently within the aperture, a biasing member that provides continuous force, and an anchor element reception zone. This segmentation allows each component to perform its specific function while maintaining overall system reliability without excessive complexity.
Solution Approach 2:
The biasing member is pre-loaded to continuously urge the locking slide into the aperture before the anchor element is even inserted. This preliminary action ensures that the locking mechanism is already in position to prevent backout, and the anchor element simply needs to be inserted to trigger the locking action, rather than requiring complex post-insertion locking procedures.
2Reliability
If a biasing member with locking slide is added to prevent backout, then the reliability of anchor element retention is improved, but the device complexity increases
Solution Approach 1:
The locking slide and biasing member are merged into a compact assembly that fits within the existing aperture footprint. The locking slide integrates the anchoring function with the locking function, while the biasing member provides both the locking force and the release mechanism through a single continuous element, reducing the number of separate components needed.
Solution Approach 2:
The biasing member is designed to automatically engage the locking slide into the aperture position without external intervention. Once the anchor element is inserted, the system self-locks through the elastic recovery of the biasing member, eliminating the need for separate locking procedures or additional actuation mechanisms.
3Reliability
If the locking slide covers the proximal end of the anchor element, then the reliability of preventing backout is improved, but the ease of operation for anchor element insertion deteriorates
Solution Approach 1:
The locking slide is designed to be dynamically movable rather than fixed, allowing it to be pushed back by the incoming anchor element during insertion. The biasing member provides the restoring force that automatically returns the slide to its locking position after insertion, creating a dynamic system that adapts to the insertion process rather than resisting it statically.
Solution Approach 2:
The biasing member pre-positions the locking slide in the aperture before insertion begins, creating a clear pathway for the anchor element. The slide's initial position and the biasing member's force are calibrated to allow smooth passage of the anchor element while ensuring immediate engagement and locking once insertion is complete.
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 solution effectively secures anchor elements within the spinal fixation system, ensuring stability and preventing backout, thereby enhancing the durability and effectiveness of spinal fusion procedures.
Implementation Method 1
The biasing member is elastically deformable. In a first position, the biasing member urges the locking slide in a first direction in which at least a portion of the locking slide enters the aperture in the plate.
Data Source
AI summary
The present invention relates generally to medical devices and methods for use in spinal surgery. In particular, the disclosed devices relate to a spinal fixation system and an intervertebral spinal implant assembly sized and dimensioned for the lumbar spine implantable via an anterior or anterolateral approach. The devices include an implant, bone screws, and an improved locking mechanism to prevent the back out of screws.