Abstract: A computer-implemented method of planning knee replacement surgery including receiving an input, generating a three-dimensional model, characterizing a morphology of the bones based on the three-dimensional model, determining one or more implant-related or morphological parameters based on at least one of the 3D model and the morphology, performing at least one simulations, optimizing a position, an orientation and optionally a size of an implant, optionally optimizing a position, an orientation and optionally a size of the implant, and outputting patient-specific planning information to at least one of an external computing device, visual display and a computer-readable storage device.