Eleven-year implant survival rates of the all-polyethylene and metal-backed modular Optetrak posterior stabilized knee in bilateral simultaneous cases.

A prospective randomized study was conducted to determine if a design change in the articular surface geometry introduced in the Optetrak total knee to increase prosthetic joint conformity and further reduce polyethylene stress had any impact on implant survival, particularly when the all-polyethylene version of the implant was used. Forty-seven patients undergoing bilateral simultaneous total knee arthroplasties were randomized for the side, receiving an all-polyethylene tibial component and followed up for a mean 11.6 years. Survival rates for the all-polyethylene and metal-backed modular versions of the implant were both 98%, excluding a single case of deep infection. Survival rates with revision for aseptic loosening as an end point were 100%. The increase in tibial and femoral radii in the coronal plane of the Optetrak posterior stabilized knee did not result in a reduced implant survival rate in either the metal-backed modular or all-polyethylene versions of the implant.