What Causes Fluid to Build up After a Knee Replacement Surgery?

Fluid buildup can occur after a knee replacement because of infection, according to Healthline. This can result in aspiration or drainage of the fluid or revision surgery to correct the problem.

Sometimes infection occurs in the new replacement joint after surgery, resulting in fluid buildup, swelling and tenderness, states Healthline. This can happen due to contamination in the operating room, although this occurs rarely because of stringent measures taken to keep these areas bacteria-free. A fluid buildup due to infection starts with unusual swelling. A patient needs to contact a physician immediately after noticing anything unusual. A doctor aspires or suctions away the fluid. Because the symptoms and not the underlying problem is treated through aspiration, the fluid is sent to a lab to identify the infection. The patient is given antibiotics to control the infection, although a virulent infection can require revision surgery.

Although a patient can undergo revision surgery in order to treat the infection and prevent further fluid buildup, this procedure has certain risks and complications, explains Healthline. It can result in worse infection, bone tissue loss, implant failure and deep vein thrombosis. In some cases, heterotopic bone forms, increasing the risk of infection. When the faulty implant is removed, it can fracture the bone.