With this method, only the damaged joint surface at the head of humerus is replaced, with the addition of a metallic crown. This is referred to as shoulder cap prosthesis.
The prosthesis therefore consists of a cap for the natural humeral head, making this the most minimal form of shoulder joint replacement.
The advantage of this method is that it preserves the bone material of the humeral head, the surgical intervention is relatively small, and blood loss is kept to a minimum. The cap prosthesis does, however, require a sufficiently large contact area, as well as a stable bone condition. This means it is not suitable for osteoporosis patients, for example.