A system comprising: a see-through optical head mounted display , and at least one processing unit wherein the at least one processing unit is configured to display, by the see-through optical head mounted display, at a predetermined position, predetermined orientation or combination thereof, a virtual implant component onto a surface of a physical joint, visible directly through the see-through optical head mounted display, so as to superimpose the virtual implant component onto the surface of the physical joint, wherein the virtual implant component is a three-dimensional digital representation corresponding to at least one portion of a physical implant component, wherein the at least one processing unit is configured to receive input from a user interface to facilitate alignment of at least a portion of the virtual implant component in relationship to at least a portion of a surface of the physical joint, wherein the input comprises information based on a first parameter related to the physical joint and a second parameter related to the physical joint, wherein the first parameter comprises information related to a cortical bone, a subchondral bone or a combination thereof, and wherein the second parameter comprises information related to a normal cartilage, a diseased cartilage, or a combination thereof. a see-through optical head mounted display , and at least one processing unit wherein the at least one processing unit is configured to display, by the see-through optical head mounted display, at a predetermined position, predetermined orientation or combination thereof, a virtual implant component onto a surface of a physical joint, visible directly through the see-through optical head mounted display, so as to superimpose the virtual implant component onto the surface of the physical joint, wherein the virtual implant component is a three-dimensional digital representation corresponding to at least one portion of a physical implant component, wherein the at least one processing unit is configured to receive input from a user interface to facilitate alignment of at least a portion of the virtual implant component in relationship to at least a portion of a surface of the physical joint, wherein the input comprises information based on a first parameter related to the physical joint and a second parameter related to the physical joint, wherein the first parameter comprises information related to a cortical bone, a subchondral bone or a combination thereof, and wherein the second parameter comprises information related to a normal cartilage, a diseased cartilage, or a combination thereof. wherein the at least one processing unit is configured to display, by the see-through optical head mounted display, at a predetermined position, predetermined orientation or combination thereof, a virtual implant component onto a surface of a physical joint, visible directly through the see-through optical head mounted display, so as to superimpose the virtual implant component onto the surface of the physical joint, wherein the virtual implant component is a three-dimensional digital representation corresponding to at least one portion of a physical implant component, wherein the at least one processing unit is configured to receive input from a user interface to facilitate alignment of at least a portion of the virtual implant component in relationship to at least a portion of a surface of the physical joint, wherein the input comprises information based on a first parameter related to the physical joint and a second parameter related to the physical joint, wherein the first parameter comprises information related to a cortical bone, a subchondral bone or a combination thereof, and wherein the second parameter comprises information related to a normal cartilage, a diseased cartilage, or a combination thereof. <EOS>