An unusual epidemic of Staphylococcus-negative infections involving anterior cruciate ligament reconstruction with salvage of the graft and function

We performed a retrospective study of 13 patients who had postoperative cli nical and laboratory signs of infection after autogenous bone-patellar tend on-bone (BPTB) anterior cruciate ligament (ACL) reconstructions. From Janua ry 1991 to November 1996 we experienced only 2 infected knees in 1,300 reco nstructions, but between December 1996 and February 1997 10 patients in 70 ACL reconstructions developed a postoperative suspected infection. We found the origin of contamination (coagulase-negative Staphylococcus) in the sup posedly sterile inflow cannula. When we changed this device, we had only 1 infection in the next 400 reconstructions. The diagnosis in these cases was derived from clinical signs and laboratory results, but only 2 of 11 sampl es of aspirated synovial fluid tested positive for Staphylococcus. The mean interval between the surgery and the onset of signs of infection and the s tart of antibiotic therapy was 7.7 days. All the patients had antibiotic as sociation at the highest level. Six knees underwent arthroscopic debridemen t when the clinical signs indicated resistence to antibiotics. The normal p ostoperative rehabilitation program was modified but was not discontinued. Although recovery time was longer, overall results were similar to uncompli cated reconstructions. On the basis of our experience, we believe that when there is a notable increase in infection rates, a thorough search for cont amination is indicated. Our source of infection was material that was thoug ht to be sterile. Ultimately, early diagnosis and treatment is of critical importance to obtain good results. Even suspicion of infective postoperativ e complication should be sufficient cause to search for responsible microor ganisms and begin antibiotic therapy. Arthroscopic debridement should be pr oposed to patients with resistence to antibiotics.