Septic arthritis after arthroscopic anterior cruciate ligament reconstruction: a retrospective analysis of incidence, presentation, treatment, and cause.

PURPOSE: The purpose of this report is to summarize our experience in the diagnosis and management of septic arthritis after anterior cruciate ligament (ACL) reconstruction.
METHODS: A retrospective review was conducted of all the arthroscopic ACL reconstructions performed at our institution between 1997 and 2007. Postoperative septic arthritis occurred in 21 of 4,068 patients. The incidence, cause, presentation, laboratory results, and treatment of all infected patients were analyzed.
RESULTS: The incidence of septic arthritis after ACL reconstruction was 0.52%. The most common symptoms of the infected patients were fever, swelling, severe pain, tenderness, and restricted motion. The erythrocyte sedimentation rate, C-reactive protein level, and fibrinogen level were markedly elevated. Microbiology showed that coagulase-negative Staphylococcus was the most common bacterium. Both conservative and operative treatments were effective, and no patient had the ACL graft removed. However, the conservative group had a longer recovery time and duration of intravenous antibiotic therapy.
CONCLUSIONS: Septic arthritis after arthroscopic ACL reconstruction is a rare but potentially devastating complication. The correct diagnosis relies on clinical evaluation, laboratory tests, synovial fluid analysis, and bacterial culture. With early diagnosis and prompt treatment, the infection can be successfully eradicated. Our proposed treatment protocol is arthroscopic debridement and irrigation as quickly as possible, with retention of the ACL graft when it is still functional. LEVEL OF EVIDENCE: Level IV, therapeutic case series.