Is the total hip replacement a risky thing to do?

Not too Risky: There are some risks and these should be discussed with your surgeon. But in general the risks are low and the benefits for the right patient are significant.

Age-dependent: Replacement can work magic, but the replacements have a limited lifespan. The younger the patient, the more replacement surgeries that will be required. Also assure that the hip is actually the souce of the pain and there are not alternative surgeries.