An all-polyethylene cementless tibial component. A five- to nine-year follow-up study. An all-polyethylene cementless tibial component was used in 221 total knee arthroplasties. With one exception, failures did not occur before three years. Failure was characterized by medial subsidence of the tibial component. There was abrasion of the polyethylene on the undersurface of all components that failed. Survivorship was seven to nine years (87.1%). This study demonstrated that a flexible cementless component can function well when used with any type of bone. However, abrasion of the polyethylene that occurs from shearing forces is a concern. Polyethylene components need adequate provisions to prevent shearing or need surface treatment to prevent abrasion. 