A joint that becomes inflamed as a result of an infection is said to be septic. Damage to the joint surface or cartilage as a result of infection is termed septic arthritis.
Bacteria may enter a joint through a break in the skin, the bloodstream from another source of infection or as a result from prior surgery. Some joint infections occur without any known cause. People whose immune systems are impaired are at increased risk for septic joints. In the hand, animal or human bites are a common cause of infection.
Patients with septic joints complain of pain and swelling in the joint. The joint is hot, red and extremely painful. Range of motion of the joint may be greatly reduced. The joint is swollen and tender to the touch. Patients may also have a fever.
Your surgeon will diagnose a septic joint on clinical and laboratory exams. Laboratory studies may show an elevated white blood cell count, ESR and/or CRP (markers of inflammation). Fluid drawn from the affected joint will be purulent and can be analyzed for bacterial content. X-rays or MRI may show inflammation of the joint.
Because a bacterial infection in a joint is damaging to cartilage, septic joints are considered a surgical emergency. Non-operative treatment consists of antibiotics and/or draining the joint.
Your surgeon will wash the joint thoroughly in the operating room, either arthroscopically or through an open incision to remove the bacteria. Cultures will be taken from inside the joint to identify the type of bacteria causing the infection. Intravenous antibiotics will be given to help eradicate the infection. Blood tests over time will confirm that the infection has resolved.