Incidence of Post-operative ACL Infections, Graft Choice Makes a Difference (SS-14)

IntroductionInfections, though rare, are a devastating complication after anterior cruciate ligament reconstruction (ACLR) surgery. The purpose of this study is to determine the incidence of surgical site infection (SS-I) in a large community based sample of ACLR patients and evaluate the association of graft selection at ACLR and the risk of deep surgical site infection.MethodsA retrospective analysis of prospectively collected data from an ACLR Registry (ACLRR) was conducted. All primary ACLRs performed between 02/2005-09/2010 were included in the study. Revisions and multi-ligament operations were not included. Graft selection was reported by the surgeon to the ACLRR via intra-operative forms. The graft types evaluated included: bone-patellar tendon-bone (BPTB) autograft, hamstring autograft, and allograft (all types). SSIs, the main endpoint of the study, were identified using a validated electronic screening algorithm and adjudicated by the principal investigator. Descriptive statistics were used to describe the study cohort by graft type and logistic regression models were used to evaluate likelihood of infection by graft type (BPTB autograft as referent).ResultsDuring the study period 10626 cases enrolled in the ACLRR fit the study criteria. The overall cohort is 64% male, the average age is 29 (standard deviation (SD)=11), and their mean body mass index (BMI) is 27 kg/m2 (SD=5). The overall incidence of SSI was 0.48% (N=51), with 17 (0.16%) superficial infections and 34 (0.32%) deep infections. Hamstring autografts (N=20, 0.61%) had the highest incidence of deep SSI of the graft types (BPTB autograft: N=2, 0.07% and allograft: N=12, 0.27%), P<0.001. After adjusting for age, gender, and BMI the likelihood of a patient with a hamstring autograft to have a deep SSI was 9.2 times higher (95%CI 2.1-39.2, P=0.003) than someone receiving a BPTB autograft. The risk of infection in allografts was not statistically significantly higher than BPTB autografts. Coagulase negative staph aureus was responsible for 12 (35.3%) of the deep infections but only 1 (5.8%) of the superficial infections. Staph aureus was responsible for 7 (20.6%) of the deep infections and 12 (70.6%) of the superficial infections.ConclusionThe overall incidence of surgical site infection after anterior cruciate ligament reconstruction was 0.48%. Deep infections accounted for 0.32% and superficial infections for 0.16%. Hamstring tendon grafts had a 9.2 times higher risk of deep infection compared to patellar tendon grafts. IntroductionInfections, though rare, are a devastating complication after anterior cruciate ligament reconstruction (ACLR) surgery. The purpose of this study is to determine the incidence of surgical site infection (SS-I) in a large community based sample of ACLR patients and evaluate the association of graft selection at ACLR and the risk of deep surgical site infection.