Mechanical and medical aspects of an implant-bone connection in the femur: A three-dimensional photoelastic study of the load transfer mechanism using gamma radiation for fixing the experimental information. Comparison of two solutions of femur prosthesis

The investigation of the implant-bone connection is of significant surgical interest as the postoperative course is influenced by the primary stability of the connection. It is necessary to achieve primary stability, so that the patient can be mobilized as soon as possible without any additional orthopaedic treatment. The achievement of the so-called secondary (longtime) stability through an ingrowth of bone is only possible if a perfect fixation of the implant is reached during surgical treatment. In thi spaper two different types of prosthesis, called Viennese and Bologna models are investigated. The reason for this investigation is given by the fact that these two types present two different fixing techniques developed for long bones. The main difference between the two solutions is given by the kind of implantation and its influence on the stress distribution in the load transfer area. In suitable models the stresses in the close vicinity of the load transfer areas are compared in both implant types using suitable photoelastic models.