“…There are several ways to avoid LLD after hip replacement: (1) fix Kirschner wires on bones to serve as references points, and measure the distance before and after installation of the prosthesis by a ruler or similar device,5,16,18 (2) use a navigation system during the operation,4,5,15,19 (3) direct manual comparison of the positions of bilateral patellas or heels in surgery,9,20 (4) similar to our method, measure the distance between the center of the femoral head and the top of lesser trochanter of the fractured side before femoral neck osteotomy and after the prosthesis implantation,21,22 (5) template measuring on X-ray film before operation to confirm the osteotomy position according to the lesser trochanter or the fracture line,14 and (6) compare the tip of the greater trochanter and the femoral head center during operation 14…”