The symptoms of a loose prosthesis after hip replacement are: 1. Pain will occur, but the pain is different from the general pain, mainly when walking and exercising. When lying down or not moving, the joint may not hurt. The signs of loosening can be seen on X-rays, and the indicators of gaps and sinking of the prosthesis can be seen on the films, and the above can be measured on X-rays; 2. Positive signs of the joint can be seen on physical examination, such as positive 4-character test, positive percussion pain, positive distal display percussion pain, and normal infection indicators of joint loosening, which are not the same as the pain of joint infection. The symptoms of prosthesis loosening after arthroplasty are to be understood by the above aspects.