Shoulder prosthesis

The shoulder prosthesis has a stem, a ball head and a middle section that can be attached to the proximal end of the stem and to which the ball head can be attached. The middle section can be clamped to an attachment element that is adjustable in a first direction at the proximal end of the stem, the first direction lying in the resection plane or parallel thereto. The first direction generally runs approximately medially-laterally. The attachment element can be displaceable on the stem by means of a dovetail guide or guided displaceable in a guide bore in the stem. The middle section can be clamped against the attachment element, whereby the attachment element and the middle section can be fixed.