septic arthritis of the knee following anterior cruciate ligament reconstruction

background: knee septic arthritis after anterior cruciate ligament reconstruction is a rare but very serious complication. the purpose of this study is to evaluate the clinical course and outcome of a series of such patients.methods: ten patients with knee joint infection after anterior cruciate ligament reconstruction were enrolled. demographic data and information related to the surgical technique were collected. onset time from index procedure, clinical and laboratory findings, interval between onset of symptoms and first debridement, number and type of operations were recorded. the latest status of patients and the relationship between onset time of symptoms with final results and also time interval between onset and debridement with the final results were also studied.results: ten patients, all male, mean age 25(19-31) years, were followed for an average of 33 (18-112) months. four patients had acute infection, 5 subacute and the remained one chronic infection. in subacute and chronic infections, patients often had not systemic symptoms. for each patient 2.3 times of joint debridement and lavage were performed. the graft was removed in 50% of cases. increased erythrocyte sedimentation rate (esr) and c – reactive protein (crp) levels and synovial fluid polymorphonuclear (pmn) cells count were highly helpful in the diagnosis. joint fluid culture was positive in 40% of the patients. in the latest survey, 20% had pain with vigorous activity, 30% had symptoms of instability and 20% had limited knee range of motion.conclusion: because symptoms of infection may overlap with postoperative natural course, the diagnosis of this complication may require special attention. early detection and timely intervention can lead to graft preservation and better final results.