Interrupted Groove Bone Screw Prevents Self-Centering
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Solution Overview
Problem
Existing surgical bone screw fixation systems face challenges in achieving stable angle positioning and easy introduction at large screwing angles, often resulting in self-centering issues and difficulty in setting intended angles.
Innovation Solution
A surgical bone screw with a concave enveloping contour and an interrupted groove structure, featuring elevated portions that provide a secure and stable holding mechanism, allowing for larger angle introductions and preventing self-centering, is designed. The groove structure includes a flank section with notches that form a hipped roof or pyramid shape, ensuring a fast and secure engagement with the bone plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional bone screw with cylindrical or conical enveloping contour is used, then the screw can be introduced into the bone plate, but self-centering effects occur and the intended angle of introduction cannot be set or achieved with difficulty
Solution Approach 1:
The patent applies asymmetry by providing a non-rotationally symmetrical groove structure on the screw head, specifically an interrupted groove pattern that creates asymmetric elevated portions. This asymmetric configuration prevents self-centering effects during insertion into the bone plate, allowing the surgeon to maintain the intended angle of introduction without the screw automatically centering itself, thereby resolving the contradiction between ease of introduction and angle positioning precision.
2Shape
If the groove structure on the screw head is continuous, then the screw head has a smooth surface, but the engagement with the bone plate is not fast enough and breakout risk increases
Solution Approach 1:
The patent applies segmentation by dividing the continuous groove structure into interrupted segments, creating discrete elevated portions on the screw head. These segmented elevated portions engage with the bone plate at multiple discrete points, providing faster and more secure engagement while reducing the risk of breakout compared to a continuous smooth surface configuration.
3Strength
If a bone screw with flattened portions and wedge clamping is used, then blocking effect is achieved, but the blocking effect appears worthy of improvement
Solution Approach 1:
The patent applies local quality by concentrating the blocking function in specific localized elevated portions created by the interrupted groove structure, rather than relying on distributed flattened portions. These localized elevated portions create focused engagement points with the bone plate that provide superior blocking effect and angle stability, improving upon the conventional wedge clamping approach.
4Adaptability or versatility
If a bone screw is designed for large angle introduction, then angle versatility is improved, but self-centering effects and difficulty in setting intended angle persist
Solution Approach 1:
The patent applies asymmetry through the non-rotationally symmetrical interrupted groove structure on the screw head, which prevents self-centering effects during insertion at various angles. This asymmetric configuration maintains the surgeon's ability to set and maintain the intended angle of introduction across a range of angles, thereby improving both angle versatility and ease of angle setting simultaneously.
Data Source
AI summary
The invention relates to a surgical bone screw comprising a shaft which has a bone thread and comprising a blocking means for interacting with a bone plate or for directly anchoring in the bone, in particular in the cortical bone. The surgical bone screw also comprises a screw head which has a rotationally symmetrical enveloping contour. The blocking means has a rib structure with at least one flank structure portion extending in the circumferential direction. According to the invention, the lateral surface of the enveloping contour has a constant or stepped concave progression, and the rib structure flank portion which extends in the circumferential direction is interrupted at least once in the circumferential direction, in particular multiple times, such that at least one elevation, in particular a plurality of elevations which are spaced in the circumferential direction, is produced in order to interact with the bone plate or with the bone in a blocking manner.