Inverted Shoulder Prosthesis Cervico-Diaphyseal Angle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reverse shoulder prostheses experience conflicts between the humeral implant and the bony glenoid during adduction movements, leading to patient pain and potential loosening of the glenoid base, due to their cervico-diaphyseal angle and eccentric axis of the hemispherical surface.
Innovation Solution
A reverse shoulder prosthesis with a humeral implant having a cervico-diaphyseal angle of 135°, which reduces the conflict by altering the orientation of the humeral reception surface and positioning the axis of the sphere lower on the scapula, minimizing contact with the glenoid during adduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reverse shoulder prostheses use a cervico-diaphyseal angle of 155° or 145°, then the prosthesis structure is established, but conflict occurs between the humeral implant and the bony glenoid during adduction movements causing patient pain and loosening
Solution Approach 1:
The patent changes the cervico-diaphyseal angle parameter from conventional values of 155° or 145° to a new value of 135°. This parameter modification alters the orientation of the humeral reception surface and the position of the sphere axis, thereby reducing the conflict between the humeral implant and the bony glenoid during adduction movements while maintaining joint stability
2Object-affected harmful factors
If the cervico-diaphyseal angle is reduced to 135°, then the conflict during adduction is reduced, but the orientation and position of the humeral implant change
Solution Approach 1:
The patent systematically changes geometric parameters including the cervico-diaphyseal angle (to 135°), the orientation of the humeral reception surface (making it more vertical), and the position of the sphere axis (lowered relative to the scapula). These coordinated parameter changes resolve the adduction conflict while creating a new functional configuration
Data Source
Figure 1~7
AI summary
The prosthesis has a humeral implant (2) and a glenoidal implant, which possesses a base fixed to a scapula and glenoidal sphere (15) fixed to the base by a fastening member. The humeral implant includes cervicodiaphysal angle that is equal to 135 degrees. A symmetry axis of hemispherical surface of the glenoidal sphere is off-centered with respect to the fastening member. The humeral implant includes a humeral insert fixed to an epiphyseal head.