<s>[INST] I had my knee replaced 3 yrs ago, and in the first year a stitch did not close and I got strep and staph in the open wound...I went to wound therapy and the last culture was clear, but I still have ongoing pain in the knee since then, could that infection be deeper and not see in the wound culture. [/INST] Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Any superficial infection which has not healed in quick time is t be treated as deep infection. I suggest you get an X-ray of the knee joint along with Complete blood count , ESR , ASO and CRP. Any infection in the joint would be evident in the X-rays now. Hope I have answered your query. Let me know if I can assist you further. </s>