<s>[INST] I just got back from a long bus trip 9 days all total and my feet are really swollen. They haven t been gong down at night. I also have a very bad knee that I am having replaced in July. What kind of treatment do I need to get the swelling down. My ankles swell some at the end of a normal day because I have a desk job. [/INST] Hello, I have studied your case. This can be early infection. This uptake increased due to loosening of implant or infection around implant. This can be differentiated by investigate like CRP, CBC, ESR.PCR culture is very useful if infection is suspected to find culprit organism. PET SCAN will also give more details. If infection is confirmed debridement operation is required. Hope this answers your query. If you have additional questions or follow-up queries then please do not hesitate in writing to us. I will be happy to answer your queries. Wishing you good health. Take care. </s>