[Special problem in the replacement operation in cemented prostheses].

The replacement of a loose total hip prosthesis requires a great amount of surgical skill and experience. Severe bony defects in the acetabulum should be filled by homogeneous bone grafts. Implantation of a Schneiderring together with the graft gives sufficient stability. The new shaft should be cemented very carefully, avoiding cavities between bone, cement and stem. The shaft of the femur should be reinforced by a long bridging plate.