A randomized prospective study comparing mobile-bearing against fixed-bearing PFC Sigma cruciate-retaining total knee arthroplasties with ten-year minimum follow-up

167 patients (190 knees) were randomized to receive either a mobile bearing system or a rotating-platform fixed bearing system in a total knee arthroplasty for the treatment of osteoarthritis. Follow-up was performed at 5 and 10 (minimum) years post-surgery. Outcomes reported included seven knee scoring systems (Knee Society Score, Knee Society Functional Score, Oxford Knee Score, Western Ontario and McMaster Universities Arthritis Index, Short-Form Health Survey Physical and Mental Components (SF-12 PCS; SF-12 MCS), Knee Injury and Osteoarthritis Outcome Score), the presence of radiolucent lines and implant survival (measured by revision). At 5 years post-operation, there were no significant differences between the fixed bearing and mobile bearing groups in all knee scoring systems. At 10 years, there were significantly better outcomes in the mobile bearing group compared to the fixed bearing group in the Oxford Knee Score, WOMAC Score, SF-12 PCS, KOOS ADL and KOOS Sport/Rec Score systems. There were no significant differences observed between groups in the incidence of radiolucent lines or implant survival at all time points.