a- PARTIAL SHOULDER ENDOPROSTHESIS
A shoulder endoprosthesis is based on the human shoulder joint. Just like natural shoulder joints, it too comprises a glenoid cup and a humeral head which is mounted on a prosthesis stem
Partial endoprosthesis: If the cartilage layer in the glenoid cavity is in good condition (for example after a humeral fracture), this does not need to be replaced. Then only the humeral head is replaced by an artificial humeral head fitted to a prosthesis stem. Following the operation, the artificial humeral head sits in the natural glenoid cavity. This is referred to as a partial endoprosthesis or hemi-endoprosthesis .
b- TOTAL SHOULDER ENDOPROSTHESIS
Total endoprosthesis: If the joint cartilage is damaged on both parts of the joint, both on the humeral head and in the glenoid cavity, all the components of the diseased shoulder joint are replaced: the damaged glenoid cavity is replaced by a prosthetic cup. The deformed humeral head is replaced by an artificial humeral head which is fitted to a prosthesis stem. This is referred to as a total endoprosthesis. A total endoprosthesis requires a functioning rotator cuff which provides the artificial joint with stability and mobility .