Polyaxial Bone Anchoring Coupling Assembly With Spring Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyaxial bone anchoring devices face challenges in ease of handling during surgery and lack modularity, limiting their versatility and increasing stock-keeping costs.
Innovation Solution
A coupling assembly with a pressure element featuring circumferentially extending spring portions that engage the receiving part, allowing for easier assembly and preventing upward movement of the bone anchoring element, combined with modular rod receiving elements that support rods of varying diameters, enabling interchangeable closure mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a traditional polyaxial bone anchoring device is used, then the device provides bone anchoring functionality, but it is difficult to assemble during surgery and lacks modularity
Solution Approach 1:
The device is divided into distinct modular components: a receiving part, a pressure element, and interchangeable rod receiving elements. This segmentation allows each component to be independently manufactured, sterilized, and assembled, significantly improving ease of assembly during surgery while maintaining necessary functionality.
Solution Approach 2:
The receiving part is designed as a universal component that can accommodate different rod receiving elements through standardized interfaces. This multi-functionality allows the same receiving part to work with various rod configurations and closure mechanisms, enhancing ease of operation across different surgical applications.
2Adaptability or versatility
If a non-modular bone anchoring device is used, then the device structure is simple, but it limits versatility and increases stock-keeping costs
Solution Approach 1:
By segmenting the device into modular components (receiving part, pressure element, rod receiving elements), the system achieves versatility through combinatorial possibilities while keeping individual components relatively simple. This allows hospitals to stock only the receiving parts and interchangeably swap rod receiving elements, reducing overall inventory requirements.
Solution Approach 2:
The universal receiving part design enables a single component to serve multiple functions by accommodating different rod receiving elements. This increases versatility without proportionally increasing complexity, as the core receiving part remains unchanged across different configurations.
3Reliability
If the pressure element is rigid, then it provides stable clamping, but it cannot engage with the receiving part to prevent upward movement
Solution Approach 1:
The pressure element incorporates spring portions that provide dynamic, elastic engagement with the receiving part. This elastic engagement allows the pressure element to deform during assembly for easier insertion while maintaining stable clamping force once positioned, resolving the contradiction between rigidity for stability and flexibility for ease of assembly.
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
Facilitates easier assembly and enhances the versatility of polyaxial bone anchoring devices, reducing stock-keeping costs by allowing for a variety of applications and customizable configurations.
Implementation Method 1
The pressure element has at least one spring portion that extends over a length in a circumferential direction and that is configured to engage a portion of an inner wall of the receiving part
Implementation Method 2
The spring portion is compressible in a radial direction
Data Source
AI summary
A coupling assembly for coupling a rod to a bone anchoring element, and including a receiving part having a first end, a second end, and an accommodation space having an opening at the second end for inserting a head of the bone anchoring element, a pressure element insertable from the first end, positionable in the accommodation space, and configured to hold the head, the pressure element having at least one spring portion extending circumferentially around the pressure element and being radially compressible, and a rod receiving element separable from the pressure element, wherein in a first position, the spring portion is configured to engage an engagement structure at an inner wall of the receiving part to prevent movement of the pressure element towards the first end, and wherein the rod receiving element is configured to move the pressure element from the first position towards the second end.