Spinal Rod Connector for Collinear Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for extending posterior spinal constructs require the removal of stable, in situ pedicle screws, which destabilizes the spine and necessitates invasive surgical procedures, especially when transitioning between different vertebral levels or rod diameters.
Innovation Solution
A spinal rod assembly and method that allows for the collinear extension of an existing in situ spinal rod without removing the last bone fastener, enabling attachment to a new rod of a different diameter, and providing a kit of rod connectors to facilitate connections between rods of varying diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the full in situ rod is removed and replaced by a longer rod to extend the construct, then the construct can be extended to different vertebral levels, but the spine becomes destabilized during surgery and large skin incisions are required
Solution Approach 1:
The invention divides the rod extension process into segments: the existing in situ rod remains in place while a separate rod extension component is added collinearly to it. This segmentation allows the original rod to maintain spinal stability while the extension component provides the additional length needed to reach different vertebral levels, eliminating the need to remove and replace the entire rod system.
Solution Approach 2:
The rod extension is designed to nest collinearly with the existing in situ rod, forming a continuous spinal construct. The extension component contains features that allow it to interface with and extend from the original rod, creating a nested configuration that maintains structural integrity and spinal stability while achieving the desired length extension.
2Ease of operation
If setscrews are loosened to lift the in situ rod for attaching a rod extension, then the rod can be extended collinearly, but large skin incisions and soft tissue access are still required
Solution Approach 1:
The invention introduces intermediate connector components that facilitate the attachment of the rod extension to the in situ rod without requiring complete removal or extensive manipulation of the original fixation system. These intermediary elements enable collinear extension while minimizing the need for large incisions and soft tissue disruption, reducing surgical invasiveness.
3Adaptability or versatility
If intermediate connectors are used to transition between different rod diameters in the lumbar-to-thoracic or thoracic-to-cervical spine, then rods of different diameters can be connected, but the construct becomes more voluminous
Solution Approach 1:
The invention applies local quality by designing transition components that are precisely tailored to specific diameter transitions between rod segments. Rather than using bulky universal connectors, the solution employs locally optimized interface elements that match the specific diameter requirements at each transition point (e.g., lumbar-to-thoracic or thoracic-to-cervical), minimizing the volume added to the construct while maintaining adaptability to different rod sizes.
Data Source
AI summary
It is an object of the present invention to overcome at least some of the problems associated with elongating an existing pedicle screw and rod construct. To this end, there is proposed a spinal rod assembly for elongating an in situ spinal posterior rod system by connecting the spinal rod construct to a head of an in situ bone fastener. The spinal rod assembly according to one embodiment comprises a rod connector and at least one rod fastener, wherein the rod connector comprises a first connector head and a second connector head, connected by an elongated bar, and forming a space between the first and second connector heads. The first connector head comprises a first pocket for receiving a first rod end, while the second connector head comprises a second pocket for receiving a second rod end.