DOS 2018

102 · DOS Abstracts 6-year Radiosteriometric Follow-up on a RCT with Comparison of the Vanguard Tibial Component with either Regenerex® or Porous Plasma Spray Coating in Total knee Arthroplasty Karen Dyreborg, Nikolaj Winther, Thomas Lind, Gunnar Flivik, Michael Mørk Petersen Department ofOrthopaedicSurgery, Rigshospitalet; Department ofOrthopaedic Surgery, Gentofte, Herlev Gentofte Hospital; Department of Orthopaedics, Skåne University Hospital, Lund Background: Regenerex® is a porous titanium construct with a 3D intercon- necting pore structure and biomechanical characteristics close to that of normal trabecular bone. Purpose / Aim of Study: The aim of this study was to compare this structure to the Porous Plasma Sprayed (PPS) tibial implant, with non- interconnecting pore structure, after uncemented total knee arthroplasty (TKA). Materials and Methods: 61 patients (mean age=63(49-71), F/M=35/26) planned for an uncemented Vanguard TKA (Biomet, Warsaw, Indiana, USA) at Hørsholm Hospital (n=41) or at Gentofte Hospital (n=20) were random- ized to receive either a Regenerex® or a PPS tibial component (31/30). RadioSteriometric Analysis (RSA) using the tibial components, marker-based technique, was performed postoperatively, at 3 months, 6 months and at 1, 2 and 6 years with measurement of migration (segment motion and maximum total point motion (MTPM)). All patients had the clinical results monitored with the Knee Society knee and function scores. 55 patients attended the 6-year follow-up. Statistics: Mann-Whitney U test. Results are presented as mean (range). Findings / Results: One patient had died and 4 was re- operated (infection=2, mechanical reasons=2) during the 6-year period. All reoperations were in the Regenerex®-group. The total 6-year MTPM was 1.40mm (0.51-3.71) for the PPS-group and 2.67mm (0.37-15.42) for the Regenerex®-group (p=0.43). The 2 to 6-year MTPM was 0.40mm (0.10-3.01) in the PPS-group and 0.56mm (0.11-4.48) in the Regenerex®-group (p=0.61). Conclusions: We did not find any significant differences between the PPS- and Regenerex®-group with regards to total long-term migration or migration be- yond 2 years. Since no patient was revised due to aseptic loosening both im- plants are considered to work well with regards to tibial component fixation and biocompatibility. 43.