Fenestrated Bone Screw Cement Guide for Precise Spinal Delivery
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Solution Overview
Problem
Existing surgical systems face challenges in efficiently delivering bone cement or other flowable materials to target locations within the boney anatomy, particularly in the posterior thoracolumbar and sacral space of the spine, using fenestrated bone screws.
Innovation Solution
A surgical system comprising a cement delivery guide with a three-part assembly of a hollow outer sleeve, inner sleeve, and inner rod, designed to securely couple with a fenestrated bone screw, allowing for the precise delivery of bone cement through a fenestrated channel and counterbore, utilizing deformable tangs and engagement features for stable attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fenestrated bone screw is used to channel delivery of BGM and/or cement, then the bone growth and solidification is promoted, but the delivery control and precision to target location is insufficient
Solution Approach 1:
The delivery system is segmented into multiple functional components: an outer sleeve that interfaces with the fenestrated bone screw, an inner sleeve that provides controlled material flow, and an inner rod that enables precise positioning. This segmentation allows each component to perform its specific function optimally while working together to achieve precise target delivery.
Solution Approach 2:
The inner sleeve acts as an intermediary between the cement delivery source and the fenestrated bone screw channel. It mediates the flow of bone cement, controlling its delivery through the fenestrations to the target location, thereby enabling precise placement while maintaining the bone growth promotion function.
2Adaptability or versatility
If various tools are used to deliver BGM and/or cement material, then the delivery flexibility is increased, but the system complexity and operational difficulty increase
Solution Approach 1:
The system merges multiple functions into a single integrated assembly. The outer sleeve, inner sleeve, and inner rod are combined into one unified delivery system that interfaces with the fenestrated bone screw. This integration maintains delivery flexibility while reducing the number of separate tools and steps required, thereby simplifying the overall system.
Solution Approach 2:
The delivery system is designed with universal applicability to work with fenestrated bone screws while providing multiple delivery modes through the adjustable inner sleeve and rod configuration. This multi-functionality allows the same system to adapt to different delivery scenarios without requiring multiple specialized tools.
3Manufacturing precision
If a multi-component assembly is used for cement delivery, then the delivery control is improved, but the assembly time and procedural steps increase
Solution Approach 1:
The system employs a nested configuration where the inner rod is positioned within the inner sleeve, which in turn is positioned within the outer sleeve. This nested structure allows for compact storage and simplified assembly, as components can be sequentially inserted into one another, reducing assembly time while maintaining precise delivery control through the hierarchical structure.
Solution Approach 2:
The inner rod and inner sleeve are pre-configured in a nested arrangement before insertion into the outer sleeve. This preliminary preparation reduces the number of steps required during the actual surgical procedure, allowing for faster assembly and deployment while maintaining the precise delivery control provided by the multi-component design.
Data Source
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AI summary
Various bone cement guides are disclosed that may connect directly to a fenestrated bone screw or connect to a spinal construct that is coupled to a fenestrated bone screw. In various embodiments, cement guides may include a three-part assembly including a hollow outer sleeve (30) and a hollow inner sleeve (20) with a removable inner rod (10). In various embodiments, the hollow inner sleeve may be movable between a retracted position and an extended position and in the extended position a distal end of the inner sleeve may splay outward and capture the head portion of a fenestrated bone screw. In other embodiments, a distal end of the outer sleeve may surround and capture tabs of an extended tulip head connector while the inner sleeve couples to an inside surface of the extended tulip head connector.