I just came back from the doctor's with a diagnosis of septic arthritis. I've been scheduled for arthroscopy this afternoon so I'm trying to find out everything I can about this problem. The first question is: do I really need this surgery?

Septic arthritis is also known as infectious or bacterial arthritis. As the name suggests, there is an invading microorganism causing inflammation of the synovial membrane lining the joint.

Septic arthritis can occur in a natural or prosthetic (replacement) joint or in joints damaged from rheumatoid arthritis. The bacteria can come from some other place in the body. The microorganisms travel via the bloodstream directly to the joint.

Septic arthritis can cause serious damage and destruction to the cartilage even after it has been removed. This is why early treatment is important. The diagnosis can be difficult to make without an arthroscopic exam. Lab results and imaging tests may not be enough to tell.

Once the surgeon looks inside the joint, a clear cause for the problem can be identified. The joint can be irrigated with a saline solution to flush out any remaining bacteria.