My father has been having a lot of pain in his left hip but his doctor says that this is being caused by arthritis in his back. How is it that the pain is in the hip?
Pain often migrates, or radiates, from one part of the body to another. A good example is when someone has a heart attack - often their pain is in the left arm or up into the jaw. In the case of your father, many people who have arthritis in the lumbar spine, the lower back, feel the pain radiate down into the hip or groin area.

The important part of getting proper treatment is for a physician to find out where exactly the pain is coming from, the hip itself or the spine. Only then can the pain be treated properly.