Robotic-arm assisted surgery using the Stryker Mako System is currently FDA approved for total hip replacement, as well as for partial and total knee replacement surgeries. A specialized CT scan of the joint obtained prior to surgery is used for pre-operative planning and takes into account the entire mechanical axis of the extremity. Live feedback during the actual surgery also allows for procedure planning to continue intra-operatively. The ultimate end product of robotic-arm assisted surgery is a well-balanced joint with motion and function that may be improved compared to that experienced after traditional joint replacement surgery.