Spinal Rod Extension via Pedicle Screw Insertion
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Solution Overview
Problem
Existing spinal rod extension mechanisms are bulky and invasive, making it difficult to perform minimally invasive surgery by bypassing existing pedicle screw heads, which can lead to complications and patient discomfort.
Innovation Solution
A spinal rod extension design that includes a connector portion to insert through an existing pedicle screw head and a lip to engage the existing spinal rod, allowing for a low-profile, minimally invasive attachment by passing through existing pedicle screw heads rather than bypassing them, with a method involving the removal of locking caps and securement using clamps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing spinal rod extension mechanisms bypass existing pedicle screw heads, then the extension can be attached to existing spinal instrumentation, but the mechanism becomes bulky and invasive, leading to patient discomfort and complications
Solution Approach 1:
The connector portion is inserted through the existing pedicle screw head, nesting the extension mechanism within the existing hardware footprint rather than bypassing it externally. This allows the extension to utilize the existing screw head as a pathway, eliminating the need for bulky external bypass mechanisms and reducing soft tissue disruption.
Solution Approach 2:
Instead of bypassing the pedicle screw head from the outside (conventional approach), the connector portion passes through the screw head from the rod end, inverting the traditional attachment methodology. This reversal enables a low-profile design that minimizes invasiveness while maintaining secure attachment capability.
2Object-affected harmful factors
If a low-profile connector portion is inserted through the existing pedicle screw head, then patient discomfort and invasiveness are reduced, but the complexity of securing the extension increases
Solution Approach 1:
The extension device is segmented into distinct functional portions: a connector portion for insertion through the screw head, a lip for engaging the rod end, and a securing mechanism. This segmentation allows each component to perform its specific function efficiently, reducing overall complexity while maintaining low-profile design benefits.
Solution Approach 2:
The connector portion acts as an intermediary element that bridges the existing pedicle screw head and the extended rod portion. By using this intermediate connector rather than directly modifying either the screw or rod, the system achieves secure attachment with minimal invasiveness and manageable complexity.
3Reliability
If the connector portion is secured to the existing spinal rod through the pedicle screw head, then a stable connection is achieved, but the procedure requires removal of locking caps and additional securing steps
Solution Approach 1:
The connector portion is designed to be inserted through the pedicle screw head before final rod placement and securing. This preliminary positioning allows the connector to be properly seated and aligned, facilitating subsequent securement steps and ensuring connection stability from the outset.
Solution Approach 2:
The securing process merges multiple functions into integrated steps: the connector portion simultaneously engages the screw head, positions the rod extension, and prepares for locking cap reattachment. This merging of functions reduces the number of separate operations required, improving surgical efficiency while maintaining reliable connection.
Data Source
AI summary
A spinal rod extension includes a rod portion, a connector portion, a lip, and a connector. The connector portion is mounted to the rod portion. The connector portion is configured for insertion through a screw head of an existing pedicle screw that is used to secure an existing spinal rod. The lip is mounted to the rod portion, and is configured to engage at least a portion of an end of the existing spinal rod. The connector is configured to secure the connector portion to the existing spinal rod.