<s>[INST] Yes. In 1986 I had my first primary hip replacement due to a car wreck. In 1994 I had my first hip revision on the same hip as the first did not take without cement. Second revision, same hip in 2004 on the acetabular. Over this 30 year period I ve lost much bone in my pelvis as well as the trochanter which is now unattached and drifting. Three nights ago I developed extreme pain in the subject hip and was taken by ambulance to the ER for examination. A large blood clot was found in the subject pelvis causing the pain and a lot of nervous fear on my behalf. Might you sense a relationship? [/INST] Hi there. Blood clots in the pelvis may need not necessarily be related to hip replacement. Since you have not disclosed your age, but have a 30-year history of undergoing surgical operations, I am assuming that your age might be more than 50. If you are not moving around too much as you have been having a lot of pelvic bone loss and Chat Doctor.  If on account of prior multiple surgeries done earlier or due to added medical illnesses you might be taking any anticoagulation medicines, it might be due to bleeding inside the soft tissues. So I suggest that you get a venous ultrasound Doppler examination done for your abdomen. Go through your medications with your doctor to see if you're taking any medicines such as warfarin or aspirin etc. Also get relevant blood investigations to see IG your bleeding parameters are normal or not. </s>