We report the results of a consecutive series of total knee arthroplasties with use of a modular posterior stabilized prosthesis after a mean follow-up of twelve years (range, ten to eighteen years). In the five years since the original publication of our study, two additional knees were revised; one was revised for aseptic loosening and one, for polyethylene wear with tibial osteolysis. With mechanical failure as an end point, the fifteen-year survival was 96.8%. With failure defined as any reoperation, the fifteen-year survival was 90.6%. Osteolysis occurred in eight of the 117 knees with a minimum ten-year follow-up. With the relatively small number of subjects, no significant association was identified between polyethylene thickness or sterilization method and osteolysis. A significant association was identified between younger patient age and osteolysis. We continue to routinely implant a similar modular posterior stabilized total knee prosthesis.