Five months ago I had my 3rd hip revision of the acetabular component from a total hip received in 1984 when I was 29.The total hip was for post Legg Calves Perthes disorder and later osteoarthritis. I have a large 4 inch diameter bruise behind my knee on hamstring. Appeared for no reason along with extreme tightness and pain in hamstring. This is the second time this has appeared, having happened a month ago in Feb. 07. That tiime I was advised by the doctor on call at orthopedist office to go to the emergency room for a possible blood clot. Dopler ultrasound was done and no blood clot was found. I was sent home, told to ice hamstring and elevate leg for a few days, and discontinue any anti-inflammatories. My surgeon found no evidence of problems on xrays and a cbc showed no sign of infection. Now for no reason another large bruise, same area has appeared with same pain as before. I'm still walking with a cane because pain in the joint has prevented me from walking w/no support.What could be the reason for this bruising and pain in an area away from the hip? The dr suggested my pain on walking is due to nerves being stretched with this revision, and has diagnosed possible sciatic nerve injury which could go away or linger .