Modular Bone Anchor with Dual Helical Threads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spinal implantation techniques face challenges in securely anchoring bone screws without breaching vertebral bodies, which can lead to nerve damage and require revision surgeries due to anatomical variations and the risk of screw protrusion.
Innovation Solution
A bone fixation apparatus with an insert having a geometric pattern for tool engagement and dual helical threads for secure bone engagement, combined with a modular bone screw system that reduces the risk of breaching by providing improved toggling strength and adjustable fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bone screw is directed into the vertebral body, then fixation is achieved, but there is a risk of breaching the vertebral body which can cause nerve damage and require revision surgery
Solution Approach 1:
The bone anchor system is divided into separate components: an insert with external threads that engages the bone, and a bone screw with internal threads that engages the insert. This segmentation allows the insert to be precisely positioned and oriented before the screw is attached, reducing the risk of breaching the vertebral body while maintaining secure fixation.
Solution Approach 2:
The insert acts as an intermediary component between the bone and the bone screw. It provides a secure anchor point in the bone that the bone screw can engage, allowing for controlled force distribution and reduced risk of direct screw-to-bone breaches that could damage nerves.
2Object-affected harmful factors
If the screw is redirected after a medial breach is recognized, then nerve protection is achieved, but more bone is removed and fixation is compromised
Solution Approach 1:
The insert is pre-positioned and secured in the bone before the bone screw is attached. This preliminary action allows the surgeon to verify correct positioning and orientation, ensuring that the final fixation path does not breach the vertebral body or endanger nerves, thereby avoiding the need for redirection and subsequent bone loss.
3Stability of the object's composition
If a rigid structure is created between adjacent vertebral bodies using bone screws and metal rods, then spinal stabilization is achieved, but anatomical variations and patient-specific requirements cannot be accommodated
Solution Approach 1:
The bone anchor system incorporates modular and adjustable components that can be configured to match patient-specific anatomy. The insert and screw can be positioned at varying depths and orientations, and the system can be adapted to different vertebral structures, providing both stabilization and anatomical versatility.
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 apparatus provides enhanced securement in bone tissue, reducing the risk of screw pull-out and nerve damage, while allowing for anatomical adaptation and modular adjustment to suit individual patient needs.
Implementation Method 1
The first helical thread is engageable with the third helical thread such that the bone anchor is coupled to the insert
Implementation Method 2
A second helical thread is disposed in the lumen of the insert
Data Source
Figure 1A~1B
Figure 1C
Figure 2A
AI summary
A bone fixation apparatus includes an insert and a bone anchor. The insert has open ends defining a lumen. A first thread is disposed on an outer surface of the insert and a second thread is disposed in the lumen. The insert is configured for threadably engaging bone. A driving tool is releasably attachable to the insert. The bone fixation apparatus also includes a bone anchor with a bone screw member and a housing. The bone screw member extends from the housing and has a third thread along a shank of the bone screw member. The third thread of the shank is engageable with the second thread of the lumen such that the bone anchor is coupled to the insert.