This study evaluated 117 patients younger than 65 years (average, 56 years) in whom mobile-bearing total knee arthroplasties were inserted. All patellae were resurfaced with a mobile-bearing patella implant. Followup averaged 102 months (range, 60-171 months). The average knee score was 91 points, with a pain score of 27 points (possible 30 points). There were eight (7%) revision surgeries in this series, with four malpositioned implants, one infection, and one case of osteolysis. Two patients had bearing revisions for bearing dislocation and polyethylene wear. Survivorship at 14 years was 88%.