Bone Anchor Connection Sleeve for Spinal Instrument Stability
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Solution Overview
Problem
In spinal surgery, extension members of bone anchors can compress or spread inadvertently, causing difficulties in advancing instruments or elements to the bone anchor, and existing solutions do not provide a simple, stable, and easy-to-handle connection device.
Innovation Solution
A connection device with a sleeve that partially encases the extension members, featuring an inclined contact surface to generate a clamping force, maintaining the extension members' separation and stability, and allowing easy installation and removal, while also providing a hollow interior for instrument passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If extension members are compressed towards each other to maintain stability, then stability is improved, but the pathway narrows causing difficulties in advancing instruments
Solution Approach 1:
The connection device is divided into a first connection portion and a second connection portion that can independently engage with extension members. This segmentation allows the device to maintain stability through engagement while preserving a patent pathway for instrument advancement by preventing complete compression of the extension members toward each other.
Solution Approach 2:
The connection device acts as an intermediary element between the extension members and the surgical instruments. It provides a stable connection point while maintaining a clear pathway through its structure, allowing instruments to be advanced without requiring compression of the extension members.
2Ease of operation
If extension members are spread apart to facilitate instrument passage, then ease of operation is improved, but premature break-off occurs
Solution Approach 1:
The connection device is designed to engage with the extension members before instrument advancement occurs. This preliminary engagement stabilizes the extension members in their separated position, preventing premature break-off while maintaining the pathway open for instrument passage.
Solution Approach 2:
The connection device serves as a stabilizing intermediary that holds the extension members in a separated state during instrument advancement, preventing them from collapsing or breaking off while allowing instruments to pass through the maintained pathway.
3Reliability
If a collar is used to maintain parallel orientation of extenders, then reliability is improved, but device complexity increases
Solution Approach 1:
Instead of using a single complex collar structure, the connection device is segmented into a first connection portion and a second connection portion. Each portion independently engages with extension members, simplifying the overall structure while maintaining the ability to hold extension members in a parallel, separated orientation.
Solution Approach 2:
Rather than using a traditional collar that constrains extension members from the outside, the connection device engages with the extension members from the inside through its connection portions, inverting the conventional approach and simplifying the structural design while achieving the same stabilizing effect.
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 connection device prevents compression and spreading of extension members, maintains a defined distance, and facilitates instrument passage, enhancing the ease of use and stability during minimally invasive surgery, suitable for various bone anchors.
Implementation Method 1
The contact surface is shaped and oriented such that when the sleeve is placed around the extension member and moved towards the bone anchor, a clamping force is generated which at least temporarily maintains or keeps the sleeve on the extension member
Implementation Method 2
The contact surface is shaped and oriented such that when the sleeve is placed around the extension member and moved towards the bone anchor, a clamping force is generated
Implementation Method 3
the contact surface of the sleeve and a cooperating surface of the extension member are inclined, such that an increasing clamping force is generated when the sleeve is mounted on the extension members
Data Source
AI summary
A connection device includes a sleeve having a first end, a second end above the first end, a longitudinal axis, and a wall that extends at least partially around the longitudinal axis. An extension member of a bone anchoring device is insertable through the first end into the sleeve to position the sleeve around at least part of the extension member. The wall has an outer surface and defines a laterally extending opening. A surface at a lower end of the opening extends inwardly from the outer surface by a first distance to facilitate insertion of a free end of the extension member from the first end into the opening, while a surface at an upper end of the opening extends inwardly from the outer surface by a distance greater than the first distance to restrict the free end from extending past the upper end of the opening.