Bone Anchor Assembly with Debris Scraper Ring for Modular Spinal Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spinal fixation devices face challenges in modifying the selection of multi-planar and mono-planar screw assemblies during surgery, as existing methods are cumbersome and can weaken the bone anchor or cause fractures when changing implants, limiting the flexibility of surgical procedures.
Innovation Solution
A spinal fixation system featuring a universal shank head that can be snapped onto either multi-planar or mono-planar pivoting receiver sub-assemblies, allowing for independent insertion and later decision-making on implant placement, with a bone anchor assembly including a frusto-conical outer surface and a closed ring retainer for secure attachment, enabling efficient switching between different types of implants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If surgeons remove implanted devices and replace them with other types, then implant selection flexibility is improved, but bone anchor purchase strength deteriorates and surgical time increases
Solution Approach 1:
The system divides the bone anchor assembly into separable components: a reusable bone anchor portion that remains in the bone, and interchangeable receiver portions that can be attached or detached. This allows surgeons to change implant types without removing the bone anchor from the bone, preserving purchase strength while maintaining flexibility.
Solution Approach 2:
The universal bone anchor portion can work with multiple types of receivers (multi-planar, mono-planar, different rod configurations), making it a multi-functional component that supports various implant configurations. This eliminates the need to remove and replace entire bone anchor assemblies when changing implant types.
2Adaptability or versatility
If surgeons remove implanted devices and replace them with other types, then implant selection flexibility is improved, but surgical time increases
Solution Approach 1:
By segmenting the bone anchor into a permanent anchor portion and interchangeable receiver portions, the system enables quick swapping of receivers without time-consuming removal and reinsertion procedures. The modular design allows for rapid attachment and detachment of different receiver types.
Solution Approach 2:
The bone anchor portion is inserted into the bone first, establishing a secure foundation before the surgeon decides on the final implant configuration. This preliminary action allows for later attachment of different receiver types without requiring removal of the anchor, saving surgical time.
3Stability of the object's composition
If complete bone anchor assemblies are inserted as units, then implant stability is improved, but surgical flexibility deteriorates
Solution Approach 1:
The system segments the complete bone anchor assembly into a stable, reusable bone anchor portion that provides consistent fixation, and interchangeable receiver portions that provide surgical flexibility. The anchor portion maintains stability in the bone while the modular receivers allow for configuration changes.
Solution Approach 2:
The system transitions from a static, fixed configuration to a dynamic, adaptable system where the receiver portion can be changed after the bone anchor is established. This allows the implant to evolve from a stable foundation to a flexible final configuration based on intraoperative findings.
Data Source
AI summary
A bone anchor assembly includes a receiver with a central bore having a seat surface proximate a bottom opening and a channel for receiving a rod, and a snap ring positioned within a recess located in the lower portion of the central bore above the bottom opening. The assembly also includes a bone anchor with a capture portion having a horizontal capture recess and an anchor portion opposite the capture portion, and a scraper ring positioned into an upper end of the capture recess. The scraper ring is engaged by an inwardly-protruding annular edge surface upon the uploading of the capture portion through the bottom opening to drive the scraper ring downward along the recessed surface to sweep the upper portion of the capture recess of bone debris, after which the snap ring snaps into the swept upper portion capture recess to capture and hold the capture portion of the bone anchor to the receiver.