Low Profile Tulip Assembly for Minimally Invasive Spinal Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pedicle screw systems are large and bulky, making them difficult to install during minimally invasive surgery (MIS) and causing tissue damage, and they often require pre-operative assembly and multiple components, which complicates the surgical process.
Innovation Solution
A low profile tulip assembly that can be coupled to a pedicle screw after its insertion, allowing for separate locking of the tulip assembly's orientation and the rod's position, reducing the complexity of installation and minimizing tissue trauma by eliminating the need for pre-operative assembly and reducing the risk of cross-threading and tulip splaying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional pedicle screw systems are used, then bone fixation function is provided, but the system size is large and bulky causing tissue damage
Solution Approach 1:
The system is divided into separate components: a pedicle screw that can be inserted first, followed by a tulip assembly that attaches to the screw head. This segmentation allows each component to be optimized independently, with the tulip assembly providing the rod-receiving function in a more compact form factor that reduces tissue damage compared to conventional integrated systems.
Solution Approach 2:
The tulip assembly is designed with a nested structure where the rod is received within the tulip body, and the entire assembly attaches to the pedicle screw. This nested configuration minimizes the overall volume of the system while maintaining all necessary functions, thereby reducing tissue damage.
2Ease of operation
If conventional pedicle screw systems are used, then bone fixation function is provided, but pre-operative assembly and multiple components complicate the surgical process
Solution Approach 1:
The system separates the pedicle screw insertion from the rod attachment process. The screw is inserted and secured first, then the tulip assembly is attached to the screw head and locked in place. This segmentation simplifies the surgical workflow by allowing each step to be completed and verified before proceeding to the next, reducing overall complexity despite multiple components.
Solution Approach 2:
The pedicle screw is inserted and positioned in the vertebra before the tulip assembly is attached. This preliminary action allows the screw to be securely in place and properly positioned before adding the remaining components, simplifying the overall assembly process during surgery.
3Ease of operation
If conventional pedicle screw systems are used, then bone fixation function is provided, but installation difficulty increases during minimally invasive surgery
Solution Approach 1:
The system allows the pedicle screw to be inserted and secured through minimally invasive techniques first, then the tulip assembly with pre-attached rod can be coupled to the screw head. This segmentation enables easier installation during MIS by breaking down the complex assembly into manageable steps that can be performed through small incisions.
Solution Approach 2:
The tulip assembly can be pre-assembled with the rod attached before surgery, and the compression cap can be pre-installed. This preliminary preparation reduces the complexity and time required during the actual surgical procedure, improving productivity during minimally invasive surgery.
4Reliability
If conventional pedicle screw systems are used, then bone fixation function is provided, but post-operative disassembly issues occur
Solution Approach 1:
The compression cap is installed during surgery to permanently lock the tulip assembly to the pedicle screw and secure the rod in place. This preliminary locking action during the surgical procedure ensures long-term stability and prevents post-operative disassembly issues, maintaining fixation reliability.
Solution Approach 2:
The compression cap serves as a separate locking component that is added to the assembly during surgery. By extracting the locking function into a distinct element rather than integrating it into the basic structure, the system achieves reliable permanent fixation while maintaining clarity in the assembly process.
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 tulip assembly facilitates efficient spinal fixation and correction surgeries by allowing for easier installation, reducing tissue trauma, and preventing post-operative disassembly issues, thereby enhancing the effectiveness of MIS techniques and reducing patient recovery time.
Implementation Method 1
an upper portion including a plurality of flexible protrusions extending from the lower portion. According to one exemplary embodiment the plurality of flexible protrusions are configured to provisionally couple a rod
Implementation Method 2
an outer tulip member including a first position and a second position, the first position being configured to enable an expansion of the lower portion of the inner tulip member and the second position being configured to compressibly lock the lower portion of the inner member on the bone fixation device
Data Source
AI summary
An exemplary tulip assembly configured to be coupled to a head of a bone fixation device includes an inner tulip member including a lower portion configured to couple the head of the bone fixation device and an upper portion including a plurality of flexible protrusions extending from the lower portion. According to one exemplary embodiment the plurality of flexible protrusions are configured to provisionally couple a rod. The exemplary tulip assembly also includes an outer tulip member including a first position and a second position, the first position being configured to enable an expansion of the lower portion of the inner tulip member and the second position being configured to compressibly lock the lower portion of the inner member on the bone fixation device. Moreover, the present exemplary tulip assembly also includes a cap having a generally planar top and at least one locking member extending from the top. Wherein the at least one locking member is configured to compress the flexible protrusions to securely lock the rod within the tulip assembly.