The present invention discloses an alignment device, system, and method of using the alignment device. The alignment device includes a femoral portion coupled to the femoral bone and a tibial portion mounted on the bone. A method for measuring alignment characteristics of a prosthetic knee joint arranged between a femur and tibia are disclosed. The method may include obtaining an alignment device. The alignment device may include a femoral portion, a tibial portion, and wherein at least one of the femoral portion and the tibial portion include at least one sensor. The method may also include coupling the alignment device to the femur and tibia and determining a first range of motion. The method may further include performing a knee replacement operation and determining a second range of motion.
