Spinal Screw With Retractable Tip Reduces Insertion Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spinal fixation systems face challenges in achieving accurate positioning and reducing insertion torque and the risk of bone fracturing during screw placement, due to individual spinal curvature and anatomy variations, which complicates the alignment and increases operating room time.
Innovation Solution
A spinal screw design featuring a self-drilling and self-tapping mechanism with protrusions or cutting flutes, and a retractable tip element coupled with a spring, which reduces insertion torque and eliminates the need for pre-drilling and tapping, while allowing for precise placement and reduced bone trauma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a self-drilling spinal screw is used to reduce insertion torque and eliminate pre-drilling, then surgical time is reduced and bone trauma is minimized, but the risk of bone fracturing during insertion increases
Solution Approach 1:
The tip element transitions from a retracted state during insertion to an extended state after insertion. During insertion, the tip remains retracted to minimize bone trauma and fracturing risk. After the screw is fully inserted, the tip extends to provide enhanced engagement with the bone, ensuring secure fixation without requiring pre-drilling or tapping.
Solution Approach 2:
The spinal screw is divided into distinct functional components: the threaded shaft for bone engagement, the head for fixation device attachment, and the movable tip element for enhanced distal engagement. This segmentation allows each component to perform its specific function optimally - the threaded shaft provides gradual insertion with reduced torque, while the tip element provides additional anchoring after insertion.
2Object-affected harmful factors
If traditional fixation systems with pre-drilling and tapping are used, then bone fracturing risk is reduced, but surgical time increases and insertion torque requirements increase
Solution Approach 1:
The spinal screw is designed as a self-drilling system where the threaded shaft creates its own insertion path through the bone without requiring separate pre-drilling or tapping steps. The threads on the shaft progressively engage the bone during rotation, allowing the screw to drill and tap itself into the vertebral body in a single continuous motion, thereby eliminating multiple surgical steps.
Solution Approach 2:
The tip element is pre-configured in a retracted position before insertion to minimize bone trauma during the insertion process. After insertion is complete, the tip element is then extended to provide enhanced engagement. This preliminary positioning of the tip element allows the screw to be inserted with reduced torque and bone trauma, followed by activation of the tip for secure fixation.
3Reliability
If accurate positioning and alignment of fixation elements are achieved, then fixation stability is improved, but the complexity of positioning and guidance increases
Solution Approach 1:
The spinal screw incorporates a movable tip element that can be positioned at different states (retracted during insertion, extended after insertion) based on the specific operational phase. This localized adaptability allows the same device to optimize for both insertion ease and final fixation stability, with the tip element providing enhanced engagement only when needed for secure anchoring.
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 spinal screw design decreases insertion torque, reduces the risk of bone fractures, shortens surgical time, and enhances the accuracy and efficiency of screw placement, minimizing x-ray and anesthesia exposure.
Implementation Method 1
A retractable tip element is also positioned within the through hole of the shaft and is operationally coupled to the spring
Implementation Method 2
A spinal screw design featuring a self-drilling and self-tapping mechanism with protrusions or cutting flutes
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A spinal screw for positioning within bone for use in surgical procedures, the spinal screw having a head and a shaft, the shaft having a proximal end and a distal end. A through-hole extends from the head through the shaft to the distal end of the shaft. The through-hole defines a longitudinal axis of the spinal screw and a spring is positioned within the shaft. A retractable tip element is also positioned within the through hole of the shaft and is operationally coupled to the spring.