An orthopaedic prosthesis is disclosed comprising a tibial tray (14) including a distal surface (22) and an opening (60) defined in the distal surface. The tibial tray includes an inner wall (70) extending inwardly from the opening to an intermediate wall (72) to define a first pocket (60) in the tibial tray. The intermediate wall includes a plurality of second openings (82), and a rim wall (84) extends inwardly from each second opening to a base wall (86) to define a plurality of inner pockets (80) in the tibial tray, each inner pocket including a central recess (100) and an undercut channel (102). The distal surface and the intermediate wall have a surface roughness (Ra) in the range of 3.5 microns to 6.5 microns. Each inner pocket has an inner peripheral edge (122) that is defined by an imaginary line on its rim wall, the inner peripheral edge having a peripheral edge length, the tibial tray has a total peripheral edge length that is equal to the sum of the peripheral edge lengths of the plurality of inner pockets, and the tibial tray has a total opening surface area that is equal to the sum of the surface areas of the narrowest openings of the plurality of inner pockets. The ratio of the total peripheral edge length to the total opening surface area is in a range of 0.31 to 0.46.
