None of biomarkers, such as synovial fluid glucose, alpha-defensin, synovial C-reactive protein (sCRP), interleukin-6 (sIL-6), leukocyte esterase, and lactate dehydrogenase, has yet been validated in a representative study for infections after ACLR so the literature does not support their introduction in clinical practice [25,26,27,28,29,30,31,32,33,34,35,36,37]. This evidence concerns the gene CRP and infection.