A tibial tray component includes a tibial tray portion with a post portion protruding from a bone-contacting side of the tibial tray portion. The tibial tray portion may include ribs extending along the bone-facing side in areas of high stress during the gait cycle. The post portion may include at least one fin projecting outwardly from the post portion and extending along a portion of the length of the post portion. A cut block assembly includes a cut block and at least one pin. The cut block may include several mounting locations for the pin. The pin may include an anti-rotation portion and a tapered free end.