Lavage of the operative and contralateral knee for comparison was performed under anesthesia prior to arthroscopy by the infusion of sterile saline into the knee joint followed by the immediate withdrawal into the syringe. Sixteen asymptomatic control subjects also contributed knee samples. The concentrations of 17 inflammatory cytokines/chemokines were measured using a multiplexed immunoassay panel. Pre-operative magnetic resonance imaging findings and cytokine assay results were compared to "gold-standard" intraoperative findings.