What causes fluid to build up after a knee replacement surgery?

Knee replacement surgery, or a knee arthroplasty, relieves pain and repairs damage to a diseased knee joint. Mayo Clinic staff describes the surgical process. Surgeons cut damaged bones and cartilage out of your thighbone, shinbone and kneecap.

They replace damaged parts with artificial joints constructed out of metal alloys, plastics and polymers. Polymers, a chemical compound, dissolve and absorb in the body as new bones begin growing. The type of artificial joints chosen by your doctor depends on your age, weight, activity level and health. The artificial limbs mimic the natural hinge movements of your knee joints. The American Academy of Orthopaedic Surgeons website says it takes between three to six months for swelling to subside. Fluid build-up sometimes develops after knee replacement surgery.

Mayo Clinic staff says knee replacement surgery helps pain and disability associated with osteoporosis, rheumatoid arthritis and avascular necrosis, a condition that develops when bone tissue dies because of restricted blood flow. You are a good candidate for this procedure if knee pain limits your mobility when sitting, standing or bending, and you've tried weight loss, physiotherapy, medications and other methods to improve knee function.


Surgeons put bulky dressings on your knee after surgery to prevent fluid build-up around the knee. Mayo Clinic staff says these bandages stay on your knee for a day or two to make sure fluid is draining properly. If you don't care for your wounds, fluid will build up because of lack of blood flow. Wear elastic hoses and compression stocking sleeves to assist circulation in your legs and prevent fluids from pooling around your knees.


Infections cause fluid build-up. Mayo Clinic staff says infections develop years after surgery, caused when bacteria travels in your bloodstream to the incision site. Symptoms of infection include fluid drainage in the surgical site, fevers higher than 37.8 degrees C, chills, redness, tenderness and swelling. Doctors prescribe antibiotics to get rid of infections. If antibiotics don't work, you have to undergo surgery to replace the infected joint with a new one to correct the condition.


Fluid build-up occurs after knee replacement surgery with increased wear and tear. The American Academy of Orthopaedic Surgeons says athletic activities loosen small particles referred to as "wear debris" in the joint, causing pain and fluid build-up. Stress results in fluid build-up and inflammation near loose joints. To prevent pain and inflammation, you will need a revision operation.