That's terrible TBR. I have a leg ulcer in the achilles tendon or soleus are of the left leg that won't go away. Had it for ~ 5 years now and made the leg swell. I've done exercise to reduce it but at times too much walking/cycling makes it swell slightly again. Vascular surgeon says all arteries and veins are clear (after 4 ultrasounds), and they can't work out why it doesn't go away. Blood clot sounds worrying for any type of leg operation.Reality is any operation has a degree of risk and we lose people from complications with straight forward procedures all the time. No doubt hip replacements would be more highly represented in deaths than most simple procedures because the recipients tend to be older and more likely to have other underlying conditions.
I once accompanied a fairly well known AFL player for an achilles tendon repair only to have the procedure postponed when they lost the patient before on the table, a reasonably fit 40 something year old man who developed a blood clot during the surgery. Needless to say, it was a very difficult task to convince them to head back in the following day.