Bone Screw Cutting Tip for Self-Starting Bone Insertion
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Solution Overview
Problem
Existing bone screws face challenges in accurately inserting into the desired entry point without turning or skiving out, particularly in shorter lengths, and require additional instruments for preparation, which complicates the procedure and may compromise fixation.
Innovation Solution
The bone screw design features a distal end with a conical tip and radially outward cutting edges on threads, allowing it to cut its own path into bone at various angles, reducing the need for additional instruments and maintaining fixation potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a flute is created in the thread to form a vertical cutting edge, then initial screw insertion is improved and additional equipment is reduced, but fixation potential within the boney anatomy is reduced
Solution Approach 1:
The thread is segmented into two functional zones: a proximal portion with complete threading for fixation, and a distal portion with interrupted threading forming cutting edges for bone insertion. This segmentation allows the screw to simultaneously provide both cutting capability and fixation strength.
Solution Approach 2:
Different portions of the screw thread have different qualities: the distal portion has interrupted threads with sharp cutting edges for efficient bone penetration, while the proximal portion has continuous threads optimized for bone engagement and fixation. This local differentiation resolves the contradiction between cutting efficiency and fixation strength.
2Ease of operation
If the screw is rotated into bone with a flute feature, then insertion is facilitated, but the screw may turn or skive out of the entry point
Solution Approach 1:
The screw is designed with pre-formed cutting edges at the distal tip that create an initial pilot path in the bone before the main threading engages. This preliminary action guides the screw along the intended trajectory and prevents turning or skiving during insertion.
Solution Approach 2:
The screw automatically creates its own insertion path through the sharp distal cutting edges that cut bone as the screw is rotated into place. This self-service capability eliminates the need for pre-drilling while maintaining insertion stability through the self-centering action of the cutting edges.
3Manufacturing precision
If additional instruments are used to prepare the entry point, then accurate insertion is improved, but device complexity and procedure time increase
Solution Approach 1:
The screw combines multiple functions into a single instrument: it serves as both the cutting tool (creating the entry path) and the fixation device (threaded portion). This multi-functionality eliminates the need for separate drilling and insertion instruments, reducing device complexity while maintaining insertion accuracy.
Solution Approach 2:
The screw is self-preparing, creating its own entry path through the bone using its distal cutting edges without requiring external drilling or preparation instruments. This self-service capability simplifies the procedure while ensuring accurate entry point placement through the controlled action of the cutting edges.
Data Source
AI summary
Various bone screws configured to be implanted into bone and methods of use are provided. In an exemplary embodiment, a bone screw is provided with an elongate shank having at least two threads thereon, and having a distal facing surface with at least two cutting edges. The cutting edges can be configured to cut bone as the bone screw is rotated into bone, thereby forming a path for the threads.