Reverse Shoulder Articular Locking Assembly for Stable Bone Anchor Fixation
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Solution Overview
Problem
Existing reverse shoulder prostheses face issues with wear disparity between metal and polymer components and potential unintended disconnection, necessitating improved connection mechanisms for joint assembly components.
Innovation Solution
The development of an articular component with a deflectable portion and locking mechanism that secures to a bone anchor, featuring a deflectable portion with compression slots and a rotation control zone to minimize relative motion and enhance stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a typical reverse shoulder assembly uses a low friction polymer articular body and metal humeral anchor, then the joint can articulate smoothly, but the metal and polymer wear at different rates and there is a risk of unintended disconnection
Solution Approach 1:
The articular body is segmented into multiple functional zones including a locking member with engagement features, a deflectable portion with compression slots, and a rotation control zone with alignment features. This segmentation allows each zone to address specific problems: the locking member prevents disconnection, the deflectable portion absorbs wear, and the rotation control zone ensures proper alignment, thereby resolving the wear disparity and disconnection risk while maintaining connection stability
Solution Approach 2:
The deflectable portion acts as an intermediary element between the locking member and the articular body core. It provides a compliant interface that accommodates differential wear between metal and polymer components while transmitting loads, thereby reducing the risk of unintended disconnection and managing wear disparity without compromising connection stability
2Ease of operation
If the articular body is made of low friction polymer to ensure smooth articulation, then joint movement is facilitated, but wear occurs at different rates compared to metal components
Solution Approach 1:
Different zones of the articular body are designed with distinct properties: the articulating surface uses low friction polymer for smooth joint movement, while the locking member and deflectable portion incorporate reinforcement features and compression slots to manage wear loads. This local differentiation allows smooth articulation to be maintained while addressing wear compatibility through structurally optimized regions
Solution Approach 2:
The articular body employs composite construction combining polymer materials with embedded reinforcement structures in the locking member and deflectable portion. This composite approach maintains the low friction properties of polymer for smooth articulation while adding wear-resistant characteristics through the reinforced zones, thereby achieving both smooth joint movement and wear compatibility
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 solution provides enhanced stability and reduces the risk of disconnection between components, ensuring secure and durable joint assembly.
Implementation Method 1
a deflectable portion with compression slots and a rotation control zone to minimize relative motion and enhance stability
Data Source
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Figure 3A
AI summary
The present disclosure are directed toward an articular assembly configured to be coupled with a bone anchor. The articular assembly may include an articular body (280) having a first end (281) and a second end (282) with an articular surface (293) disposed on or adjacent to the first end. The articular body may include a bone anchor interface (288) disposed between the first end and the second end of the articular body. The bone anchor interface may include a channel (284) formed in a circumferential surface of the articular body, a locking member (253) disposed in the channel, and/or a deflectable portion (254) disposed between the locking member and the second end of the articular body.