A fixed-bearing knee prosthesis, comprising: a femoral component having a medial condyle surface and a lateral condyle surface, a bearing having (i) a medial bearing surface configured to articulate with the medial condyle surface of the femoral component, and (ii) a lateral bearing surface configured to articulate with the lateral condyle surface of the femoral component, and a tibial tray secured to the bearing, the tibial tray having a platform with a fixation member extending downwardly from a lower surface thereof, the platform having (i) a posterior buttress extending along a posterior section of a perimeter of the platform and extending upwardly-from an upper surface of the platform, and (ii) an anterior buttress extending along an anterior section of the perimeter of the platform and extending upwardly from the upper surface of the platform, wherein the anterior buttress has (i) a first arm extending along an anterior edge of the platform, (ii) a second arm extending along the anterior edge of the platform in a direction away from the first arm of the anterior buttress, wherein the first and second arms are undercut, wherein the posterior buttress is generally Y-shaped and has (i) a first arm extending along a posterior edge of the platform and having a first undercut defined therein, (ii) a second arm extending along the posterior edge of the platform in a direction away from the first arm and having a second undercut defined therein, and (iii) a third arm extending anteriorly away from the first arm and the second arm, and wherein (i) a first imaginary line extends along a lateral-most edge of the first arm of the posterior buttress, (ii) a second imaginary line extends along a medial-most edge of the second arm of the posterior buttress and intersects the first imaginary line to define an angle of intersection (α) therebetween, and (iii) the angle of intersection is between 45-145°. a femoral component having a medial condyle surface and a lateral condyle surface, a bearing having (i) a medial bearing surface configured to articulate with the medial condyle surface of the femoral component, and (ii) a lateral bearing surface configured to articulate with the lateral condyle surface of the femoral component, and a tibial tray secured to the bearing, the tibial tray having a platform with a fixation member extending downwardly from a lower surface thereof, the platform having (i) a posterior buttress extending along a posterior section of a perimeter of the platform and extending upwardly-from an upper surface of the platform, and (ii) an anterior buttress extending along an anterior section of the perimeter of the platform and extending upwardly from the upper surface of the platform, wherein the anterior buttress has (i) a first arm extending along an anterior edge of the platform, (ii) a second arm extending along the anterior edge of the platform in a direction away from the first arm of the anterior buttress, wherein the first and second arms are undercut, wherein the posterior buttress is generally Y-shaped and has (i) a first arm extending along a posterior edge of the platform and having a first undercut defined therein, (ii) a second arm extending along the posterior edge of the platform in a direction away from the first arm and having a second undercut defined therein, and (iii) a third arm extending anteriorly away from the first arm and the second arm, and wherein (i) a first imaginary line extends along a lateral-most edge of the first arm of the posterior buttress, (ii) a second imaginary line extends along a medial-most edge of the second arm of the posterior buttress and intersects the first imaginary line to define an angle of intersection (α) therebetween, and (iii) the angle of intersection is between 45-145°.