How safe is hip and knee replacement surgery?

Both have become : Very common and routine procedures. These have the best outcomes done by surgeons who do a lot of them. However, a lot also depends on the status of the patient with obesity, malnutrion, diabetes, peripheral vascular disease, osteoporosis, presence of autoimmune diseas such as lupus, clotting disorders, prior blood clots or dvt, varicose veins and deformities in legs all having an impact.