Tulip Head Converter Structure to Prevent Pedicle Screw Splaying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for an apparatus and method to convert an open style tulip head pedicle screw to a closed style pedicle screw without adding additional surgery time or trauma to the bone, as replacing an open style tulip head with a closed style head can be cumbersome and traumatic.
Innovation Solution
A converter member is used to join with an open style tulip head pedicle screw, converting it into a closed style pedicle screw by securing a spinal fixation rod with a converter member that surrounds and secures the tulip head to prevent splaying under forces, using adhesive, press fit, snap fit, or threaded screw fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an open style tulip head pedicle screw is used, then the spinal fixation rod can be easily translated into the head, but the head may splay under forces causing the rod to move out of its fixed position
Solution Approach 1:
The converter member is divided into a body portion that interfaces with the tulip head and a rod receiving portion that interfaces with the spinal fixation rod. This segmentation allows the converter to provide both easy rod translation through the open tulip head structure and reliable prevention of splaying through the closed head structure with set screw engagement.
2Reliability
If a closed style pedicle screw head is used, then greater forces can be withstood without splaying, but additional surgery time and bone trauma are caused during replacement
Solution Approach 1:
The converter member is pre-formed as a complete assembly including the body portion and rod receiving portion. The converter is designed to be installed in a single step after the tulip head is already in place, eliminating the need for time-consuming removal and replacement of the entire screw while still providing the reliability of a closed head structure.
3Reliability
If a closed style pedicle screw head is used, then greater forces can be withstood without splaying, but additional bone trauma is caused during replacement
Solution Approach 1:
The converter member extracts only the necessary function of preventing splaying and providing closed head protection, while leaving the original tulip head and screw body in place. This selective extraction avoids the bone trauma associated with removing and replacing the entire screw, as the converter can be installed through the existing rod translation path without additional bone interaction.
4Reliability
If an open style tulip head is converted to closed style using a converter member, then the spinal fixation rod is securely fixed, but the device complexity increases
Solution Approach 1:
The converter member merges the functions of the tulip head body and the closed head protection into a single integrated component. The body portion interfaces with the existing tulip head while the rod receiving portion provides closed head security, combining multiple functions into one piece that simplifies the overall system rather than adding separate components.
Data Source
AI summary
A pedicle screw tulip head converter. The converter can have a first portion joined to a second portion. The first portion can have a surface parallel to a first portion plane, and an opening defining a first portion axis. The second portion can extend from the first portion and can have a surface parallel to a second portion plane, the second portion plane being perpendicular to the first portion plane. The second portion can have a curved surface that defines a second portion axis, the second portion axis being perpendicular to and coplanar with the first axis.