Implant orientation data representing a range of functional orientations of a first implant part relative to a first bone is determined. The first implant part is part of an implant pair to be implanted in an associated patient. The implant pair includes the first implant part and a second implant part. Second implant orientation data representing an orientation of the second implant part relative to a second bone is acquired. Implant shape data representing shapes of the first and the second implant parts is acquired. Activity data representing a desired activity of the associated patient is acquired. The desired activity has an associated original range of motion between the first bone and the second bone. The implant orientation data is determined based on the second implant orientation data, the implant shape data, and the activity data.