Dual-Mobility Reverse Shoulder Cup for Higher Motion, Lower Torque
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Solution Overview
Problem
Conventional reverse total shoulder implants suffer from high complication rates, limited functional range of motion, and increased undesirable forces due to larger glenosphere size and center of rotation offset, leading to potential implant failure.
Innovation Solution
A reverse shoulder prosthesis system featuring a dual mobility cup that articulates with both the glenosphere and humeral socket, providing two ranges of motion and reducing undesirable stresses through a smaller glenosphere and decreased offset, thereby increasing the range of motion and reducing torque on the implant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional reverse total shoulder implant uses a larger glenosphere to increase range of motion, then the range of motion is improved, but undesirable forces and torque on the implant increase leading to higher complication rates
Solution Approach 1:
The implant is segmented into two independent rotational interfaces: the first interface between the glenosphere and cup, and the second interface between the cup and humeral socket. This segmentation allows each interface to contribute independently to the total range of motion, enabling adequate mobility with a smaller glenosphere that generates lower undesirable forces and torque.
Solution Approach 2:
The invention changes the structural parameters of the implant by introducing a dual mobility cup with distinct concave and convex surfaces. The first concave surface articulates with the glenosphere while the second convex surface articulates with the humeral socket, creating a kinematic chain that multiplies range of motion without proportionally increasing forces on the glenosphere-bone interface.
2Ease of operation
If a conventional reverse total shoulder implant increases center of rotation offset to improve range of motion, then the range of motion is improved, but undesirable forces and torque on the implant increase
Solution Approach 1:
The rotational motion is segmented into two independent axes: the first rotation between glenosphere and cup, and the second rotation between cup and humeral socket. This segmentation allows the center of rotation to be positioned optimally for minimizing forces while still achieving adequate total range of motion through the combined rotational arcs of both interfaces.
3Device complexity
If a conventional reverse total shoulder implant uses a fixed articulation to reduce complexity, then device complexity is reduced, but the range of motion is limited
Solution Approach 1:
The cup is designed with dynamic mobility, allowing it to rotate independently relative to both the glenosphere and the humeral socket. This dynamic articulation creates a dual-axis rotation system that significantly increases range of motion compared to fixed articulations, while the cup itself remains a single integrated component that does not substantially increase manufacturing complexity.
Data Source
AI summary
A reverse shoulder prosthesis system is provided. The system can include a the convex surface of the glenosphere and the concave surface of the humeral socket. The convex surface, a humeral socket can have a concave surface, and a cup is positioned between cup can be moveable relative to the glenosphere and to the humeral socket.