Angled-Head Bone Fixation for Rodless Spinal Stabilization
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Solution Overview
Problem
Current posterior fusion device systems for spinal stabilization are complex, expensive, and prone to loosening of rods and screws, necessitating a more efficient and stable bone fixation system.
Innovation Solution
A bone fixation system comprising a primary fastener with an angled head and a secondary fastener, secured by a set screw, which eliminates the need for a connecting rod, providing stability through angular relationships and minimizing soft tissue trauma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional posterior fusion device systems with rods and screws are used, then spinal stabilization can be achieved, but the system becomes complex, expensive, and prone to component loosening
Solution Approach 1:
The fixation system is divided into discrete modular components: a first fastener with an angled head, a second fastener, and a set screw. This segmentation allows each component to perform a specific function independently, simplifying the overall system while maintaining stability. The first fastener anchors into the first vertebra, the second fastener anchors into the second vertebra, and the set screw secures the angular relationship between them, eliminating the need for complex connecting rods.
Solution Approach 2:
The connecting rod is extracted from the traditional fusion system and replaced by a direct angular engagement mechanism. The angled head of the first fastener and the corresponding seat on the second fastener eliminate the need for separate connecting rods, reducing component count and simplifying the system while maintaining the stabilization function.
2Stability of the object's composition
If traditional rod and screw systems are used, then spinal alignment can be maintained, but surgical trauma to soft tissue increases
Solution Approach 1:
Instead of using a rod that connects screws from the posterior aspect, the system inverts the approach by having the fasteners engage directly from the anterior or lateral aspects with an angled head configuration. This inversion of the traditional rod-screw assembly approach reduces the need for extensive posterior soft tissue dissection and retraction, thereby minimizing surgical trauma while maintaining spinal alignment.
3Reliability
If traditional fusion systems with multiple components are used, then spinal stabilization is achieved, but the risk of component loosening increases
Solution Approach 1:
The first fastener and second fastener are merged through an angular engagement mechanism where the angled head of the first fastener directly engages with the seat of the second fastener. This merging eliminates the need for separate connecting rods and reduces the number of interfaces where loosening can occur. The set screw further secures this angular relationship, creating a more reliable fixation system with reduced risk of component loosening.
Data Source
AI summary
A bone fixation system comprises a first fastener configured to anchor into a first vertebrae, a second fastener configured to anchor into a second vertebrae, and a set screw to retain the second fastener to the first fastener. The first fastener includes a shaft extending along a longitudinal axis and a head. The shaft includes a first cylindrical body. The head of the first fastener includes a second cylindrical body defining a passageway having an interior surface. The passageway defines a longitudinal axis that is different than the longitudinal axis of the shaft. The first cylindrical body of the shaft and the second cylindrical body of the head are angled relative to each other. A head of the second fastener is configured to engage the interior surface of the passageway of the head of the first fastener. The set screw retains the head of the second fastener in the passageway.