A system and device (110) for determining bone laxity. For example, the system includes a tracked probe (300) comprising at least one probe marker (310) and a computer assisted surgical (CAS) system (100). The CAS system includes a navigation system (130) and a processing device (110) operably connected to the navigation system and a computer readable medium configured to store one or more instructions that, when executed, cause the processing device to receive location information from the navigation system, generate (820) a surgical plan comprising a post-operative laxity assumption (720), collect (850) first motion information related to movement of the joint through a first range of motion, collect (860) second motion information related to movement of the joint through a second range of motion, determine (870) a post-operative laxity (710), and compare the post-operative laxity and the post-operative laxity assumption to determine laxity results.