A shoulder arthrosis – also called omarthrosis – is defined as a degenerative change of the shoulder joint. Two different types of shoulder arthrosis are to be distinguished. The first type – the idiopathic shoulder joint arthrosis – is not due to previous diseases, but to a constitutional, insufficiently developed articular cartilage. The second type – the secondary shoulder arthrosis – originates from e.g. previous diseases such as arthritis (rheumatic arthritis) or an accident with humerus fracture (fracture of the upper arm) respectively a fracture of the head of the humerus.