An SSI usually develops within 30 days of surgery - although, in some patients with a prosthetic implant, SSI can occur occur up to one year after surgery (PHE2013). Studies in the United States have shown that there is a long-term risk of developing SSI following primary hip and knee replacements, with one quarter of infections diagnosed between two and ten years following surgery (Ong rt al 2009, Kurtz et al 2010). Clinicians should bear the possibility of infection in mind when treating patients who have unresolved peoblems with their prosthesis.