Hip heads are subdivided into models for total endoprostheses and models for partial prostheses (also called hemi-prostheses):
The hip head for total prostheses is a small metal or ceramic ball that is placed onto the hip stem. Due to its conical design, the head sits firmly on the stem and requires no additional fixation.
Material selection for the hip head depends on the cup: the two components form a tribological pairing designed for the greatest possible wear resistance. The surgeon decides which combination is ideal on the basis of the patient’s individual situation.
A partial prosthesis is used mainly in the treatment of femoral neck fractures when the natural hip socket is in good condition. In this case, an artificial cup is not necessary; the joint is reconstructed by means of a hip stem and the bipolar or hemi-prosthetic head.
This head is also made of different materials.