This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection of Bones & Joints, Subject name: Orthopaedics
Most common cause of nongonococcal septic arthritis is 
Select and explain. 
A. Staph - aureus, B. H. influenza, C. Pseudomonas, D. Streptococcus
A: Staph - aureus
Answer: A: Staph - aureus 
Explanation: Ans. is 'a' i.e. Staph aureus m.c cause or septic arthritis isCommonest route of infectionCommonest joint affected-Staph aureus**-Hematogenous* knee*