Transverse Adjustable Spinal Screw for Linear Rod Alignment
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Solution Overview
Problem
Existing spinal fixation systems face difficulties in linearly arranging multiple screws into vertebral bodies, leading to improper distortion of the spine, increased operational complexity, and uncertainty due to adjustable-angle screws, particularly when multiple screws are used.
Innovation Solution
A transverse adjustable spinal screw design featuring a screw tail with an eccentric installation head and a screw seat that allows for linear alignment of screw seats, facilitated by a slidable tensioning ring and ball socket mechanism, enabling reliable connection of connecting rods without distorting the spine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If adjustable-angle screws are used to avoid excessive bending or extension of vertebral bodies, then spinal stability is improved, but screws become dislocated in left-right direction on the front plan of spine, causing difficulty in connecting rod installation
Solution Approach 1:
The screw seat is designed with transverse adjustability, allowing the connecting rod groove to be positioned at different lateral locations. This dynamic adjustment capability enables the system to adapt to the actual positions of multiple screws implanted into different vertebral bodies, ensuring that all screw seats can be linearly connected even when screws are dislocated in the left-right direction, thus resolving the contradiction between maintaining spinal stability and facilitating connecting rod installation
Solution Approach 2:
The invention changes the lateral position parameter of the screw seat relative to the screw tail axis by providing an adjustable transverse distance between the center line of the connecting rod groove and the axis of the screw tail. This parameter adjustment allows the screw seat to be positioned optimally for connecting rod installation while maintaining the angular adjustment capability for spinal stability
2Adaptability or versatility
If multiple screws are implanted into different vertebral bodies, then fixation coverage is improved, but linear arrangement of screw seats becomes difficult, increasing operational complexity
Solution Approach 1:
The transverse adjustability of the screw seat provides an additional degree of freedom for positioning. When multiple screws are implanted into different vertebral bodies, the screw seat can be laterally adjusted to ensure that all connecting rod grooves align linearly, simplifying the operation of installing the connecting rod while maintaining comprehensive fixation coverage across multiple vertebral bodies
3Ease of manufacture
If fixed-angle screws are used for simple structure, then manufacturing is easier, but vertebral bodies may be excessively bent or extended when connecting rod is locked
Solution Approach 1:
The invention combines the simplicity of fixed-angle screw structure with the functionality of variable-angle screws by providing a screw seat that can be transversely adjusted. The screw tail maintains a fixed angle relative to the vertebral body, while the screw seat can be positioned at different lateral distances from the screw tail axis, allowing the connecting rod to be installed linearly without causing excessive bending or extension of vertebral bodies
Data Source
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AI summary
The present invention provides a transverse shift screw tail, a transverse adjustable spinal screw, and an implantation method. The screw comprises a screw tail and a screw seat installed on an installation head of the screw tail, a top of the screw seat is provided with a rod groove used for placing a connecting rod, the rod groove is recessed downwards from the top of the screw seat and radially penetrates the screw seat, a bottom of the rod groove is a curved surface adapted to anouter circumferential surface of the connecting rod, and aside surface of the rod groove is provided with a locking thread fit with a locking bolt; and the screw tail comprises a fixing column capable of being screwed into a vertebral body and a platform located at an end portion of the fixing column, the platform is provided with the installation head used for connecting with the screw seat, and an eccentric distance is provided between a center of the installation head and an axis of the fixing column. According to the transverse shift screw tail, the transverse adjustable spinal screw and the implantation method, by designing a brand new screw, the screw seats are connected linearly, the installation process of the connecting rod is enabled to be reliable and effective, a spine is prevented from being improperly distorted, the difficulty of operation by a doctor is reduced and the operation effect is improved.