The standard opening for hip joint replacement is still between five and 10 inches. Not all surgeons use the mini-incision for this operation. Some patients are too large for the mini-approach.
Sometimes the skin is too tight and a longer incision is needed. In other cases, the surgeon needs to see more of the joint so a bigger opening is needed.
Chances are you got the standard incision if you didn’t ask for a small incision before the operation. If you ever have the other hip replaced, be sure and talk with your surgeon about this option.