 The two main subcategories of lower extremity prosthetic devices are trans-tibial (any amputation transecting the tibia bone or a congenital anomaly resulting in a tibial deficiency) and trans-femoral (any amputation transecting the femur bone or a congenital anomaly resulting in a femoral deficiency).A transfemoral prosthesis is an artificial limb that replaces a leg missing above the knee.Transfemoral amputees can have a very difficult time regaining normal movement.