Nested Spinal Instrument for Sacroiliac Joint Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical treatments for sacro-iliac joint disorders often fail to provide adequate stability and fusion, leading to persistent pain and instability.
Innovation Solution
A surgical instrument comprising an outer sleeve, an inner shaft, and an inner sleeve, where the inner sleeve is axially fixed and rotatable, and includes a tapered tip and a threaded connection interface with a bone fastener, facilitating precise implantation and fixation in the sacro-iliac joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a surgical instrument is used to deliver implants for fusion and fixation, then stability and fixation are improved, but the complexity of the surgical procedure and instrument increases
Solution Approach 1:
The surgical instrument employs a nested structure where an inner shaft with threaded element is disposed within an outer sleeve. The inner shaft can rotate independently within the outer sleeve, allowing the instrument to perform multiple functions (guidance, rotation, fixation) through a single integrated device, thereby improving stability without proportionally increasing overall complexity
Solution Approach 2:
The instrument is divided into functional segments: the outer sleeve that provides structural support and guidance, and the inner shaft that provides rotational capability and threaded engagement. This segmentation allows each component to be optimized for its specific function while working together to achieve reliable fixation
2Manufacturing precision
If a tapered tip is added to the inner shaft for precise implantation, then manufacturing precision is improved, but the device complexity increases
Solution Approach 1:
The inner shaft features a tapered tip at its distal end, creating a localized area with different geometric properties (decreasing diameter) compared to the rest of the shaft. This local quality change enables precise implantation and accurate positioning of the bone fastener without requiring the entire device to be complex
3Ease of operation
If the inner sleeve is made rotatable relative to the outer sleeve, then ease of operation is improved, but the reliability of the connection interface may worsen
Solution Approach 1:
The inner shaft is designed to rotate within the outer sleeve, providing dynamic adjustability during the surgical procedure. This rotational capability allows the surgeon to easily adjust and position the bone fastener, while the threaded connection ensures that once positioned, the connection remains stable and reliable
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 surgical instrument enables stable and precise fixation of bone fasteners in the sacro-iliac joint, reducing stress on the joint and promoting effective fusion, thereby alleviating pain and instability.
Implementation Method 1
the inner sleeve includes a tip that extends to the element, the tip including a tapered portion having a decreasing diameter
Implementation Method 2
the inner shaft includes a drive engageable in a torque interface with a first mating surface of a bone fastener
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A surgical instrument comprises an outer sleeve including an inner surface that defines a cavity. An inner shaft is fixed with the outer sleeve and extends within the cavity. The inner shaft includes a drive engageable in a torque interface with a first mating surface of a bone fastener. An inner sleeve is disposed between the inner shaft and the outer sleeve. The inner sleeve is axially fixed and rotatable relative to the outer sleeve. The inner sleeve includes an element connectable in a connection interface with a second mating surface of the bone fastener. Systems, spinal implants and methods are disclosed.