The present invention relates to a tibial prosthesis having an articulating component and a tray component. The articulating component is configured for attachment to the tray component. Additionally, the articulating component may be attached to the tray component in a first condition in which the articulating component is at least rotatable relative to the tray component. This allows for the tray component to be attached to the tibia in a position that provides for proper rotation of the tray component with respect to the tibia and/or prevents the tray component from overhanging the resected tibia. Then, the articulating component may be rotated and/or translated to a position that provides for proper alignment of the articulating component with a femoral prosthesis. Once in this positioned, a locking mechanism is used to rotationally fix the articulating component to the tray component.