RESUMO
BACKGROUND: The rate of septic arthritis in the knee after anterior cruciate ligament (ACL) reconstruction varies in the literature but is generally less than 1%. It has been reported to be higher in professional athletes (5.7%). PURPOSE: The primary goal was to evaluate the rate of septic arthritis after ACL reconstruction in professional athletes compared with other patients. The secondary goals were to analyze the risk factors; increased cost of infections; return to sport, satisfaction, and functional results at 1-year follow-up; and resolution rate of infections at final follow-up. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This retrospective analysis of prospective data included a continuous series of patients who underwent isolated ACL reconstruction between 2012 and 2016. The main outcome criterion was the development of intra-articular infections in the operated knee. An infection was suggested clinically (knee pain with fever and/or chills) and confirmed bacteriologically in deep tissue samples obtained during revision surgery. All infected patients underwent an emergency reoperation with lavage and debridement along with dual antibiotic therapy first by an intravenous route and then orally for 6 weeks. RESULTS: A total of 1809 of 1859 patients included in the cohort during this period fulfilled inclusion criteria; there were 1632 (90.2%) who underwent primary reconstruction and 177 (9.8%) who underwent revision. The series included 1249 (69%) men and 560 (31%) women, with a mean age of 29.1 ± 9.8 years. Ninety-eight percent of the patients participated in a sport, including 90 (5.0%) at a professional level and 712 (39.4%) competitively. Septic arthritis of the knee developed after a mean 15.7 ± 5.5 days in 7 (0.38%) patients: 5 of 1632 (0.31%) who underwent primary reconstruction and 2 of 177 (1.13%) who underwent revision. Septic arthritis did not develop in any professional or competitive athletes; all affected patients were recreational athletes ( P = .02). The risk factors identified for the development of septic arthritis on multivariate analysis were prior knee surgery (odds ratio [OR], 15; P = .002) and hemarthrosis during the immediate postoperative period (OR, 127.2; P = .002). There were no recurrent infections after a mean follow-up of 2.8 ± 1.2 years. CONCLUSION: None of the professional athletes in this cohort had septic arthritis after ACL reconstruction. There are no particular precautions to be taken in this population. The risk factors identified for the development of septic arthritis on multivariate analysis were prior knee surgery and hemarthrosis during the immediate postoperative period. Similar to all studies published on the subject, there were very few infected patients, which limits the identification of risk factors. REGISTRATION: NCT02511158 (ClinicalTrials.gov identifier).