Pain in the groin and thigh or knee several years after the initial hip replacement is usually due to wear and tear of the prosthesis after the initial replacement, osteolysis, infection, or fracture around the prosthesis due to trauma. Generally speaking, if the pain and poor ambulation after the initial replacement is due to a surgical problem, such as poor prosthesis position, perioperative infection, etc., it is important to identify the cause. It is important to identify the cause, and problems that occur 5 years or more later are mostly due to prosthesis loosening or wear. The first physical examination can find pain and pressure in the groin area, suggesting a loose acetabular side prosthesis, if the thigh or knee pain, the possible cause is a loose femoral shank side, some patients complained of pain when just standing, walking a dozen steps after the pain is reduced, mostly due to a loose prosthesis. In addition to claudication, some patients have bilateral limb inequality or pelvic tilt. X-rays reveal bone resorption near the artificial prosthesis, widening of the medullary cavity, and translucent bands around the prosthesis. The laboratory should routinely check blood sedimentation (ESR), C-reactive protein, and white blood cells. If infection is suspected, a thorough sterilization of the joint should be performed before using antimicrobial agents to check the white blood cells and bacterial culture in the joint fluid. Treatment: Basic treatment includes blood glucose treatment for diabetes and treatment of blood clots. Surgical treatment should be differentiated: Arthroplasty for infection should be done in two steps: first remove the prosthesis and bone cement, repeatedly rinse, scrape the inflammatory granulation tissue, place an occupant containing a therapeutic amount of antimicrobial bone cement (vancomycin), and perform joint replacement in the second phase after the inflammation is controlled, usually 3 months after the inflammation is controlled. In the absence of an infected history, a phase I revision arthroplasty is an option. Prosthesis selection should be considered for revision, mostly distal fixed or full-length fixed biologic prosthesis on the femoral side, and various prostheses on the acetabular side according to the specific presence or absence of bone defects and bone defects, including tantalum metal, reinforced rings, porous mesh with cement cups, etc. Revision: 3 months postoperatively.