I had hip replacement on both hips in 2010. I started to have horrible pain in middle of thighs. Doctor dismissed this because xrays, blood tests, etc showed nothing. Finally had bone scan and found that both of the femurs and the rods were not holding together at the tip of the femur, which caused end of stem pain. I have gone to the best hospitals, Hosp for Special Surgery in NY, doctors, etc. and there is nothing you can do about it!. One doctor, before doing another bone scan, said he has never seen this happen in both thighs. I believe it is the actual hip mechanism that was not suited to me. The doctor I went to last year said that this type of problem is not prevalent any more, which leads me to believe the companies who made hips replacements have changed problem. It has been 7 years, and I do get around, but out of nowhere, I pain returns. Because this does not happen that often, I think that hospitals and doctors do not care to find out how to correct this. I was told my one doctor he could replace hip, but would need to break femur.