Multi-Axial Bone Anchor Assembly with Flexible Saddle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bone anchor systems for orthopedic implants, particularly in spinal applications, lack sufficient stability and flexibility to securely fix orthopedic implants to bone while allowing for necessary spinal motion and adjustment.
Innovation Solution
A bone anchor assembly comprising a bone anchor with a head portion, a crown member, a saddle with a channel and slots for flexibility, and a sleeve that secures the anchor in place by compressing the head portion between the crown member and the saddle, allowing for multi-axial movement and enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid bone anchor system is used to provide stable fixation, then stability and strength are improved, but flexibility and range of motion are reduced
Solution Approach 1:
The bone anchor assembly incorporates a dynamic interface between the bone anchor head and the saddle through the crown member, allowing multi-axial movement and adjustment. The crown member enables the bone anchor to move relative to the saddle in multiple directions while maintaining secure fixation, thus providing both stability and flexibility simultaneously.
2Adaptability or versatility
If a flexible bone anchor system is used to allow spinal motion, then adaptability and range of motion are improved, but fixation stability and strength are reduced
Solution Approach 1:
The system transitions from a static rigid connection to a dynamic adjustable connection. The crown member allows the bone anchor to move relative to the saddle in multiple directions (multi-axial movement) while maintaining secure fixation through the compression member that holds the crown member in place, thus providing both flexibility and stability.
Solution Approach 2:
The bone anchor assembly is divided into distinct functional components: the bone anchor, crown member, saddle, and compression member. This segmentation allows each component to perform its specific function - the crown member provides flexibility through multi-axial movement while the compression member maintains fixation stability by securing the crown member between the bone anchor head and saddle.
3Ease of manufacture
If a simple bone anchor design is used to reduce device complexity, then ease of manufacture is improved, but reliability and security of fixation are reduced
Solution Approach 1:
The bone anchor assembly is divided into distinct functional components: the bone anchor with head portion, the crown member, the saddle, and the compression member. This segmentation allows each component to be manufactured independently using standard orthopedic manufacturing processes, while the assembled system provides reliable fixation through the coordinated function of all components working together.
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 bone anchor assembly provides improved stability and flexibility, allowing for secure fixation of orthopedic implants while enabling necessary spinal motion and adjustment, reducing the risk of disassembly and improving the load-bearing capacity.
Implementation Method 1
The bone anchor is secured in a fixed position relative to the saddle by compression of the head portion of the bone anchor between the crown member and the lower portion of the saddle created by threadingly advancing the compression member against the elongated member
Implementation Method 2
The lower portion including a plurality of slots rendering the lower portion outwardly flexible to receive the head portion of the bone anchor and inwardly flexible to secure the head portion of the bone anchor therein
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
In one aspect, a bone anchor assembly is provided. The bone anchor assembly includes a bone anchor, a crown member, a saddle, and a sleeve. The bone anchor assembly is configured such that the bone anchor is moveable with respect to the saddle when the sleeve is positioned around the saddle and the bone anchor is locked relative to the saddle by compression of the head portion of the bone anchor between the crown member and a seat of the saddle. In another aspect, a system for orthopedic implantation is provided. The system includes an elongated member, a compression member, and a bone anchor assembly. In another aspect, a method of assembling a bone anchor assembly is provided.