Spinal Implant Screw Lock With Deflectable Latch and Easy Inserter Release
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Solution Overview
Problem
Existing spinal implants face challenges with threaded connections that cause inserters to stick in situ, making removal difficult, and require additional steps or components for locking mechanisms, which complicate the surgical procedure.
Innovation Solution
A spinal implant with a 3D-printed deflectable latch and integral thread provides passive locking during screw insertion, offering tactile feedback and secure retention without additional devices or steps, while inserters use a barrel-cam mechanism for easy attachment and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threaded connections are used to secure the implant, then the implant can be firmly fixed in the disc space, but the inserters stick in situ and become difficult to remove
Solution Approach 1:
The implant connection system is segmented into two independent parts: a threaded engagement feature for secure fixation and a separate insertion/removal mechanism using opposing pins and a barrel cam element. This segmentation allows the threaded feature to provide strong fixation while the cam mechanism enables easy inserter attachment and removal without thread engagement.
Solution Approach 2:
The threading function is extracted from the inserter-implant interface and placed solely on the implant body. The inserter uses a non-threaded cam-based mechanism with opposing pins that engage a barrel cam element, allowing the threaded connection to remain on the implant for fixation while the inserter can be easily removed without threads.
2Reliability
If additional locking mechanisms or components are added to prevent screw backout, then screw retention is improved, but the surgical procedure becomes more complex
Solution Approach 1:
The locking function is merged into the existing fixation aperture structure through a deflectable latch with a lip that deflects outward during screw insertion and then springs back to contact and hold the screw head. This integration eliminates the need for separate locking mechanisms while providing reliable screw retention.
Solution Approach 2:
The deflectable latch provides automatic, passive locking that occurs self-service during the normal screw insertion process. The latch deflects outward as the screw is driven in, then automatically springs back to retain the screw head, requiring no additional steps, devices, or user intervention beyond the standard insertion motion.
3Productivity
If passive locking during screw insertion is implemented, then one-step locking is achieved, but the mechanism must be simple enough to not complicate the implant structure
Solution Approach 1:
The latch is designed as a deflectable, dynamic element that changes position during insertion. The lip deflects outward dynamically as the screw is driven in, then returns to its original position to provide passive locking. This dynamic behavior enables one-step locking without requiring complex mechanisms or additional components.
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 solution enables one-step locking during screw insertion, prevents backout, and simplifies the surgical process by eliminating thread-in connections and reducing procedural complexity.
Implementation Method 1
a deflectable latch having a lip at a proximal end thereof and configured to allow passage of a bone screw in a first direction through the corresponding fixation aperture and retain the bone screw within the corresponding fixation aperture after a proximal portion of the bone screw has passed the lip
Data Source
Figure 1~2A
Figure 2B~2C
Figure 2D~2E
AI summary
The present disclosure includes bone screws, spinal implant, drivers, and their assemblies thereof for surgical procedures of the spine including but not limited to anterior lumbar interbody fusion (ALIF) procedures.