Aims: The RT-PLUS Solution (PLUS Endoprothetik AG, Switzerland) is a second generation rotating hinge total knee prosthesis. It is available in a standard version with þxed cemented stems and in a modular version with variable cementless and cemented stems and multiple spacer options. We report our clinical experience with the standard system and describe the features of the newer modular version. Methods: Since May 1996, we perform constrained total knee arthroplasties using the RT-PLUS Solution System. The þrst 55 Patients have been followed-up. We performed an anamnestic and clinical examination, followed by a radiologic analysis. Results were validated according to the HSS and Knee Society scores. Results: Average follow-up time was 25.5 months (min.18 months, max.39 months). 40 patients (73%) underwent surgery because of severe axis deviation, instability or joint deformation, in 15 cases (27%) we performed revision due to implant loosening. At follow-up, the mean HSS Score had improved from 37 to 82 points, mean Knee Society score from 47 to 152 points. According to the HSS rating system, 86% of our patients showed good and excellent results. As complications we found 5 DBVTñs without thromboembolic complication, 1 patella fracture due to necrosis, 4 delayed wound healings and one transient peroneal palsy. Deep infections did not occur so far. No patient showed radiological signs of implant loosening. Conclusions: Our results show, that RT-PLUS Solution is an adequate prosthetic design for the treatment of severe knee joint destruction and for complex revision cases in TKA.