How is septic arthritis of the knee treated?

Step one: confirm the diagnosis

Fluid is drawn from the knee and tested for white cells, crystals and bacteria. Blood tests and blood cultures are taken. Ideally this happens before antibiotics, so that the bacteria can be identified and the right antibiotic chosen. An X-ray is usually taken, and sometimes an ultrasound or MRI.

Step two: washing out the joint

• Arthroscopic washout: through two or three small incisions, the joint is flushed with several litres of sterile fluid and inflamed tissue removed
• Open washout: through a larger incision, when arthroscopy is not suitable
• Repeated aspiration: in selected cases, especially some children, repeated needle drainage may be used

Some patients need a second washout if the infection does not settle within a few days. A drain may be left in the knee for a short time.

Step three: antibiotics

Antibiotics are usually started through a vein straight after samples are taken and adjusted once the bacteria are known. After improvement, many patients switch to tablets. The total course is commonly several weeks, depending on the organism, how quickly you respond and your general health. Finishing the full course matters.

Infected knee replacements

An infection around an implant is managed differently. Very early infections may be treated by washout and exchange of the plastic insert while keeping the implant. Later or established infections often need the implant removed and a new one placed, in one or two stages, along with longer antibiotics.

Care at Aman Hospital in Doha

Dr. Gelber performs arthroscopic and open washouts and coordinates with infection specialists on antibiotics. Early, gentle movement and physiotherapy begin as soon as pain allows, to prevent stiffness. Follow-up blood tests confirm the infection is clearing.