No consensus exists regarding the optimal graft choice between allogenic and autologous graft. Incidence of septic arthritis following ACL reconstruction is rare but may dependent on the graft type. Our meta-analysis assesses the difference in incidence of septic arthritis after ACL reconstruction across three groups of grafts: hamstring autografts, bone patellar tendon bone (BPTB) autografts and allografts of any type.

A literature search was performed without language restriction on PubMed and EMBASE databases. We identified 245 infected ACL grafts across 15 included studies that provided a breakdown of infection incidence by graft type. A meta-analysis was performed using a random-effects model to estimate the overall infection rates and those for different graft types. Summary risk ratios and 95% confidence intervals (CIs) were calculated and reported for each outcome. Publication bias with respect to infection rates was estimated using a funnel plot.

Our meta-analysis shows an overall ACL graft infection rate of 0.6% (CI 0.3% – 1.3%). The incidence was highest in autologous hamstring grafts at 1.1% at (CI 0.8% – 1.6%). That of allografts and autologous BPTB grafts was similar at 0.5% (CI 0.2%–1.0%) and 0.4% (CI 0.2% – 0.7%), respectively. Full breakdown of the meta-analysis results by study and graft type is reported in Figure 1.

Septic arthritis after ACL reconstruction remains a rare (<1%) but a serious complication. Allograft rates of infection were not higher than those the autografts, contrary to the theoretical concerns. Therefore a higher infection risk should not be cited as a reason for not using it. The reason for the apparently higher infection rate with hamstring autografts is unclear and requires further research. The results of our meta-analysis may aid informed discussions between surgeons and patients about the risk of infection after ACL reconstructive surgery and graft choice.