Septic Arthritis also known as Infectious Arthritis refers to infection of a joint. It may involve one or more joints. It most commonly affects the knee joint, followed by hip, shoulder and elbow. Septic arthritis should be considered as a medical emergency and treated immediately. Bacteria are the commonest organisms that cause septic arthritis. The bacteria that are commonly implicated in this condition include Staphylococcus aureus, Streptococcus, Hemophilus influenzae, Neisseria gonorrhea, Escherichia coli and Pseudomonas aeruginosa.