[The GSB knee joint: reoperation and infections]

The GSB-III knee prosthesis is one of the semi-constrained types and consequently ranks between the non-constrained condylar prostheses and the fully constrained hinges. Its kinematics can be classified as "physiological" in the sagittal plane as far as the relationship between femur and tibia in the various degrees of flexion is concerned, which is a replica of a normal knee joint. The high average range of postoperative mobility as well as the extremely low aseptic loosening rate after 10 years prove the truth of this statement. A simple operative technique requiring a few special instruments allows even the less experienced knee surgeon to be successful and to obtain good results in cases with severe deformity and poor bone quality. The survival curves of the GSB-III prosthesis (n = 638) show a cummulative success rate of over 90% after 10 years. Looking separately at cases complaining of more or less severe pain, we frequently find underlying patellar problems, the main cause for revisional surgery. This problem is not specific for our prosthesis, but must be considered a so far unsolved worldwide problem. Infections are another relatively frequent cause for revisions. Disturbed wound healing, arterial insufficiency and malignant rheumatoid arthritis are the outstanding risk factors. For a reliable comparison of the different knee prostheses we ought to have a globally accepted evaluation system, which unfortunately still does not exist.