Bone cement and more: how the artificial joint is held in the bone

In order to benefit from your artificial joint for as long as possible, it has to be firmly anchored in the bone. There are two recognised procedures used these days to ensure a firm connection between the artificial joint and the bone:

  • Cemented endoprosthesis:
    In this case a polymer, referred to as a bone cement, is used to fix the endoprosthesis. This type of anchorage can bear weight immediately after the surgery. An example of a bone cement used and trusted for decades is PALACOS® from Heraeus. The bone cement can also have antibiotics added to support infection prophylaxis.
  • Cementless endoprosthesis:
    Alternatively, the surgeon can anchor the artificial joint without bone cement. In this case, the bone slowly grows into the endoprosthesis and only creates a firm connection after some time.

The procedure used for each individual case depends on a number of factors, including the age of the patient, any pre-existing conditions, such as diabetes and the bone quality. Globally, regional differences and the training of surgeons also play a role in the choice of endoprosthesis and surgical technique used.

Large studies have shown that cemented endoprostheses have a particularly long lifetime. This avoids surgery to replace joints, or at least defers it for a long time.

An aside: what is bone cement exactly?
Bone cement is not actually a cement, but is instead a polymer made up of two components. The technical name is polymethyl methacrylate (PMMA). It is mixed up from a liquid and powder immediately before insertion of the artificial joint, and then cures completely within a few minutes. The bone cement attaches the parts of the endoprosthesis firmly to the bone. Bone cement has been successfully used for more than 60 years to anchor artificial joints.