While hip replacement surgery is a very effective method for improving quality of life, it is only considered as an option for severe pain and activity restriction, and after non-operative management has been exhausted 

Hip replacements are a highly successful operation, with approximately 90-95% of people seeing an eventual improvement in their symptoms post-operatively and significant boost to their quality of life.

The approach preferred by Dr Keighley is the Direct Superior Approach or the Posterior Approach. He will discuss this with you if it comes to requiring surgery

The basic principle of a hip replacement is to replace the worn out surface of the hip with a pain-free artificial surface. The acetabulum (socket) is replaced with a metal liner and a highly cross-linked polyethylene (plastic) or ceramic metal bearing surface and the femoral head is replaced with a stem inside the bone and a head made from metal or ceramic. The stem can be either press-fit or cemented into place. These are chosen on a patient-specific basis 

more information can be found here

There are some risks associated with hip replacement, which in the general population are relatively low, but can include fracture of the bone (<1%), dislocation of the hip(1-2%), infection(0.5-2%), bleeding (1% transfusion risk), nerve injury(<0.5%) and post-operative blood clots (1-2%). Sometimes one leg may be longer or shorter than the other, but this is often only by a matter of millimeters and in most people is not detectable.