Not being a medical person, I can't give you all, but here is a site that lists some scenarios from people who had different failures. They are anecdotal and may not represent everyone, but at least give you some idea of what they felt:
http://www.bananarepublican.info/Implant_Failures.htmFrom that site, the people who talked about loosening said:
Loosening of the Femoral Component after Hip Resurfacing Scenario #1 The main symptom was pain I’d experience when I'd get up from lying down or sitting. It lasted for weeks and continued to get worse as time went on. It became obvious that something was wrong, and it caused me to schedule an appointment with my surgeon. The X-ray revealed that the femoral component had dropped or repositioned due to a loosening of the component.
Revision surgery was performed, and a large head total hip replacement femoral stem was implanted. I had my resurfaced hip for approximately 16 months before symptoms developed, and my revision surgery was performed 17 months after my original resurfacing surgery.
Scenario #2 Approximately two years after my resurfacing, a shadow appeared near the edge of the guide pin of the femoral component (i.e. radiolucency). This did not necessarily mean an implant failure was inevitable, but it was something that needed to be watched. I had had perfect function of the hip and no pain except for a little soreness when I had been on my feet all day. I had already been diagnosed as having a soft bone condition at the time of surgery with small sponge-like crevices on the top of the femur.
Later, I began getting referred pain in my knee, and I’d occasionally experience a sharp pain in the hip if I was leaning forward and putting a lot of weight on that leg. Afterward, I began getting weight-bearing pain in the leg. It was in the front of the thigh and running down to the knee, and it was different than the groin pain I had experienced before surgery.
More X-rays did not show any differences in the hip structure, and it was determined that the femoral component had loosened—not catastrophically, but it had loosened nonetheless. I began using walking aids while preparations were made for revision surgery to a large head total hip replacement stem. The revision surgery was then performed without any complications. The acetabular cup remained solid and was not replaced.
It's easy to see yourself in these situations, I took a psychology class at school and thought I had every psychological issue we were studying. This kind of thing is scary, so I usually try to rule out the worst first so that my mind can either be at ease, or deal with the situation. Have you gotten a hold of your surgeon or another surgeon to look at it and see if loosening has happened? Hopefully it hasn't and maybe this is just a muscular problem that can be treated.
Good luck, and welcome to the site. Keep us up to date...