Abstract: Apparatus, systems, and methods for developing patient-specific surgical plans are disclosed. One illustrative computer-implemented method comprises identifying anatomical parameters of a knee joint, determining a subset of implant alignment options for a knee prosthesis when implanted from among a larger set of implant alignment options, where the subset consists of each implant alignment from the larger set that satisfies one or more flexion-extension gap criteria, determining a target ligament elongation of at least one ligament of the knee joint over a range of flexion based on pre-implantation anatomy, determining, for each implant alignment of the subset, a predicted ligament elongation of the at least one ligament over the range of flexion, identifying at least one recommended implant alignment of the knee prosthesis based on the target ligament elongation and the predicted ligament elongations, and incorporating the at least one recommended implant alignment into a patient-specific surgical plan.

Abstract: Apparatus, systems, and methods for developing patient-specific surgical plans are disclosed. One illustrative computer-implemented method comprises identifying anatomical parameters of a knee joint of a patient, determining target kinematics of the knee joint based on the patient's pre-implantation anatomy, determining predicted kinematics for a number of implant alignment options for a knee prosthesis when implanted in the knee joint, identifying a recommended implant alignment of the knee prosthesis based on the target kinematics and the predicted kinematics of the knee prosthesis, and preparing a patient-specific surgical plan incorporating the recommended implant alignment.

Abstract: An apparatus, system, and method for determining a position of a hip prosthesis in a bone of a patient includes determining a set of contact points between a femoral head of a femoral prosthesis and a cup liner of an acetabular cup to be implanted into a patient based on a mechanics model. The mechanics model is indicative of mechanical motion of a hip exhibited during performance of a set of ADL or at corresponding functional positions of the patient. In some embodiments, a mathematical model may be generated based on a plurality of sets of contact points determined using the mechanics model and subsequently used to determine a resultant set of contact points.

Abstract: An apparatus, system, and method for determining a position of a hip prosthesis in a bone of a patient includes determining a set of contact points between a femoral head of a femoral prosthesis and a cup liner of an acetabular cup to be implanted into a patient based on a mechanics model. The mechanics model is indicative of mechanical motion of a hip exhibited during performance of a set of ADL or at corresponding functional positions of the patient. In some embodiments, a mathematical model may be generated based on a plurality of sets of contact points determined using the mechanics model and subsequently used to determine a resultant set of contact points.