Einfluss unterschiedlicher Knochenzemente auf das Migrationsverhalten von Tibiakomponenten in der Knieendoprothetik (Palacos® R+G vs. Refobacin Bone Cement R®).Eine In-vitro-Studie.

In spite of improvements concerning materials and implanting techniques in total knee arthroplasty (TKA) over the past years postoperative micromotion still remains a big problem. This study was designed to investigate whether there are significant differences between the new bone cements Palacos® R + G and Refobacin Bone Cement R® concerning postoperative micromotion of the tibial component in total knee arthroplasty. Micromotion was measured using radiostereometric analysis (RSA). 20 human cadaver tibiae were equally matched into two groups, 10 specimens per group. A tibial tray of the Genesis-II-system was implanted into each bone using a standardized implanting technique. Palacos® R + G was assigned to be used in one group, Refobacin Bone Cement R® was used as bone cement in the other group. All specimens were tested with an axial load of 2,000 N for 10,000 cycles. X-ray images were taken postoperatively, after 1,000 and after 10,000 loading cycles. Afterwards RSA was performed using RSA-CMS to reconstruct micromotion three dimensionally. Endpoints for radiostereometric analysis were translation along the x-, y- and z-axis, rotation around the x-, y- and z-axis as well as maximum subsidence, maximum lift off and maximum total point motion. After 1,000 and 10,000 cycles, no significant differences between the two groups could be found. The results of this study may be checked in a clinical trial using a higher number of patients.