A posterior stabilized knee orthopaedic prosthesis includes a tibial bearing and a femoral component configured to articulate with the tibial bearing. The tibial bearing includes a spine having a concave cam surface and a convex cam surface. The femoral component includes a posterior cam having a concave cam surface and a convex cam surface. During flexion, the concave cam surface of the posterior cam contacts the convex cam surface of the spine and the convex cam surface of the posterior cam contacts the concave cam surface of the spine.