An orthopedic prosthesis includes a tibial implant and a tibial insert. The tibial implant includes an upper surface, a medial side, a lateral side and a first locking structure provided on the upper surface where the medial side and the lateral side of the tibial implant are defined by a medial-lateral midline. The tibial insert includes a second locking structure provided on its bottom surface. The first and second locking structures are configured for engaging each other along an engagement direction vector when the tibial insert is inserted into the tibial base towards the posterior side. The engagement direction vector is angled away from the medial-lateral midline of the tibial implant towards the medial side of the tibial implant by a predetermine angle.