Background Total knee arthroplasty (TKA) is a successful and frequently performed procedure in orthopedic surgery.The diagnosis of peri-prosthetic joint infection following TKA remains challenging.The present study estimated the usefulness of knee skin temperature (measured by infrared thermography) and serum soluble intercellular adhesion molecule-1 (slCAM-1) in the diagnosis of post-operative knee peri-prosthetic infection.Methods Patients were divided into three groups:21 patients undergoing uncomplicated TKAs,seven with prosthesis infection,and three undergoing TKA revisions.The serum levels of interleukin-6 (IL-6),C-reactive protein (CRP),erythrocyte sedimentation rate (ESR),and slCAM-1 as well as the local knee skin temperature were measured preoperatively and on Days 1 and 7 and at 1,3,and 6 months post-operatively in Groups 1 and 3.The same parameters were measured in Group 2 at the time of prosthesis infection diagnosis.Results In Group 1,the levels of IL-6,CRP,ESR,and knee skin temperature were significantly elevated post-operatively,but reted to baseline levels within 6 months.The slCAM-1 levels were not significantly different.The mean differential temperature (MDT) and levels of siCAM-1,IL-6,CRP,and ESR differed significantly between Groups 1 and 2.The MDT had reted to normal in Group 3 by 6 months post-operatively.Conclusions Elevations in IL-6,CRP,ESR,and MDT in patients undergoing TKA could be a normal response to surgical trauma,but sustained elevations may be indicative of complications.The knee skin temperature and slCAM-1 may be used as indicators in the diagnosis of knee prosthesis infection following TKA.