Press-On Pedicle Screw Assembly With Intraoperative Interference Fit
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Solution Overview
Problem
Conventional pedicle screw systems are large, bulky, and require pre-operative assembly, leading to tissue damage and complexity in minimally invasive spinal surgeries, with traditional designs causing muscle disruption and blood loss.
Innovation Solution
A tulip assembly that securely couples to a pedicle screw via an interference fit, allowing for intra-operative assembly and reducing the system's size and height, minimizing tissue damage and simplifying installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional pedicle screw systems are used, then spinal fixation can be achieved, but the system size is large and bulky causing tissue damage
Solution Approach 1:
The pedicle screw system is divided into separate components: the pedicle screw itself and the rod-receiving device (tulip assembly). This segmentation allows each component to be optimized independently and enables modular assembly during surgery, reducing the overall system footprint and tissue damage compared to pre-assembled bulky systems.
Solution Approach 2:
The rod-receiving device is designed to fit over the pedicle screw head, with the inner diameter of the housing slightly larger than the screw head diameter. This nested configuration allows compact integration of components while maintaining ease of assembly and reducing the external dimensions of the complete assembly.
2Ease of operation
If pre-operative assembly is used, then system components are pre-configured, but assembly complexity increases and maneuverability decreases
Solution Approach 1:
By separating the rod-receiving device from the pedicle screw, the system eliminates complex pre-operative assembly requirements. Each component can be independently prepared and sterilized, then quickly assembled during surgery by simply placing the tulip assembly over the screw head, significantly improving maneuverability in the surgical field.
Solution Approach 2:
Instead of assembling the rod-receiving device onto the screw pre-operatively, the design allows the rod-receiving device to be attached intra-operatively by placing it over the screw head. This reversal of the assembly sequence simplifies the surgical procedure and improves ease of operation.
3Object-affected harmful factors
If standard paraspinal approach is used, then spinal fixation devices can be implanted, but muscle disruption and blood loss occur
Solution Approach 1:
The compact nested design of the tulip assembly fitting over the pedicle screw head reduces the overall profile of the implant system. This smaller profile enables minimally invasive surgical approaches with smaller incisions, reducing muscle disruption and blood loss while maintaining full functional capability of the fixation system.
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 enables efficient spinal fixation and correction surgeries with reduced recovery time and trauma by allowing for intra-operative assembly and a smaller, less invasive pedicle screw system.
Implementation Method 1
A tulip assembly configured to be coupled to a screw head having a first diameter includes a housing, wherein the housing defines an inner diameter configured to engage the first diameter of the screw head. The exemplary inner diameter of the housing being smaller than the first diameter of the screw head.
Data Source
AI summary
A tulip assembly configured to be coupled to a screw head having a first diameter includes a housing, wherein the housing defines an inner diameter configured to engage the first diameter of the screw head. The exemplary inner diameter of the housing being smaller than the first diameter of the screw head.