The mobile bearing knee system has been designed to combine high stability and kinetic function with or without the posterior cruciate ligament. In this kontext the MBK-system is mainly qualified for patients with sufficient kollateral ligaments. Regarding to the origin anatomy a special attachment of the articulating surface allows an anterior-posterior movement of 4,5 mm and a rotation of 53 degrees. The sagital scape of the femoral component guarantees concruency to the articulating surface throughout a range of motion from 5 degress extension to 105 degress flexion. According to this fact high stresses to polyethylene with the consequence of an increase of attrition could be reduced. From May 1997 to June 2001 236 mobile bearing knees were implanted in 220 patients. In June 2000 100 patients with 1 to 2 year follow up were investigated clinically and radiologically. The Knee Society Score was used for the clinical assessment. By using a special study questionaire pre-, intra- and postoperative data were collected. Overall results in the first cases with 1 to 2 year follow up were good to excellent. Over 90% of the whole study group represented a plain increase of score values pre- to postoperatively. Regarding to the first 100 implantations postoperative complications were seen in 3 cases (1 deep vein thrombosis, 1 fixed flexion deformity, 1 sub-luxation of the patella). Intraoperative complications were noticed by one patient because of an uncomplicated tibial fissure. One re-admission was necessary in 1 case because of a traumatic patella fracture. A reduction of pain was noticed in 89,2% after 1 year, in 100% after 2 years. In case of the radiological follow up no signs of loosening or implant failure were seen. Till June 2001 we had 2 more complications. One TKR has been revisised because of infection. One tibial component was changed because of instability and malrotation. The first results in 100 cemented mobile bearing knees were very encouraging. All patients with 1 to 2 year follw up represented good clinical and radiological results. Mechanical implant failures were not seen in any cases.
In Revision-THR the great variability of acetabular defects requires a revision-cup-system, which enables the surgeon to treat even extensive unexspected bone losses with a load stable reconstruction during the surgery. For these cases a modular revision support cup (MRS-Titan) has been developed. It allows the reconstruction of the geometric rotation centre and prevents the applied autologous or homologous bone graft in the healing phase from overlaoding. Beyond that an individual adjustment of the differently large flexible straps guarantees the solid anchoring of the revision support cup to the vital bone. The individual anatomy can be preserved in every case of acetabular destruction due to the high range of modularity the system provides. Because of the intraoperatively synthesis of all parts of the MRS-cup the approach and the traumatization of the soft tissue can be minimized. Since 1995 we implanted 95 MRS-Titan-cups out of 250 which were implanted world wide. In all cases a stable anchoring of the implant has been reached. We will report about our own follow-up and complications. In 4 MRS revisions a revitalized acetabular bone graft has been found able to host a noncemented hemispherical cup in three cases.
