Off-Axis Vertebral Access Cannula for Single-Entry Augmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vertebral augmentation techniques, such as bipedicular approaches, require multiple access cannulas, leading to increased tissue trauma and instrumentation, while unipedicular methods struggle with accessing contralateral sides of the vertebral body efficiently.
Innovation Solution
A system utilizing an introducer device with a flexible distal portion and a pulling element to navigate an access cannula, allowing for a pre-set curve to be adjusted between constrained and unconstrained states, enabling off-axis positioning within the vertebral body, combined with a flexible sheath and expandable member assembly for bone displacement and material delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a bipedicular approach is used to access contralateral side of vertebral body, then access to interior locations is achieved, but tissue trauma and instrumentation requirements double
Solution Approach 1:
The access cannula is divided into three distinct segments: a proximal straight portion for initial insertion, a middle curved portion for navigating anatomical structures, and a distal straight portion for accessing the target site. This segmentation allows each portion to perform its specific function optimally while enabling contralateral access through a single cannula rather than two, thereby reducing tissue trauma.
Solution Approach 2:
The access cannula transitions from a straight linear path to a curved three-dimensional path through the vertebral body. The curved middle portion allows the cannula to navigate around anatomical obstacles and reach contralateral locations that would be inaccessible through a straight approach, achieving versatile access without requiring multiple cannulas.
2Object-affected harmful factors
If a unipedicular approach is used to reduce tissue trauma, then instrumentation is reduced, but accessing contralateral side becomes difficult
Solution Approach 1:
The middle portion of the access cannula features a predetermined curve with a specific radius of curvature that allows the distal end to reach contralateral locations within the vertebral body. This curvature enables a single cannula to navigate the complex three-dimensional anatomy and access off-axis targets that would otherwise require multiple access points.
Solution Approach 2:
The access cannula is designed with specific geometric parameters including a curved middle portion with a radius of curvature between 10-50mm and specific length ratios between portions. These parameter changes transform a simple straight needle into a sophisticated tool capable of reaching contralateral locations while maintaining a single-entry unipedicular approach.
3Ease of operation
If straight instrumentation is used for vertebral access, then insertion is simple, but access to off-axis locations is not feasible
Solution Approach 1:
The access cannula is divided into three distinct segments: a proximal straight portion for initial insertion, a middle curved portion for navigating anatomical structures, and a distal straight portion for accessing the target site. This segmentation allows each portion to perform its specific function optimally while enabling contralateral access through a single cannula rather than two, thereby reducing tissue trauma.
Solution Approach 2:
The access cannula transitions from a straight linear path to a curved three-dimensional path through the vertebral body. The curved middle portion allows the cannula to navigate around anatomical obstacles and reach contralateral locations that would be inaccessible through a straight approach, achieving versatile access without requiring multiple cannulas.
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
Facilitates minimally invasive, efficient vertebral augmentation by reducing tissue trauma and instrumentation, allowing precise off-axis access and positioning within the vertebral body, enhancing procedural accuracy and efficacy.
Implementation Method 1
The flexible distal portion includes a pre-set curve in an unconstrained state. Tension on the pulling element is configured to be increased in response to the input provided to the actuator to move the pre-set curve from the unconstrained state to a constrained state in which the flexible distal portion at least partially straightens.
Data Source
AI summary
Systems and methods for augmenting a vertebral body. An introducer device includes a shaft having a flexible distal portion with a pre-set curve in an unconstrained state. An input provided to an actuator to tension a pulling element to move the pre-set curve to a constrained state in which the distal portion and a flexible sheath conforming to the shaft at least partially straighten. The introducer device is removable from the sheath remaining offset from a longitudinal axis. A spacer hub facilitates proximal movement of the sheath relative to an access cannula expose a balloon through a syringe-style input. A hub of the access cannula may be adjustable to selectively adjust an interference surface relative to a datum. At least two radiopaque markers may be disposed on the sheath with relative positions between the markers viewable on lateral and A-P radiography to determine the location and/or curvature of the sheath.