June 01, 2021

Why do I have sloshing sound in my knee after joint replacement?

Q: It's been a month since I had knee replacement surgery. I sometimes notice a sloshing sound in the knee. Is this normal?

A: It's probably not a serious issue, as long as you're otherwise feeling well and making progress in your rehabilitation. A possible cause is a buildup of fluid that naturally lubricates the joints (synovial fluid). The sound is likely to improve or go away with the usual rehabilitation steps, including ice, elevation and rest. Call your doctor if it doesn't improve in a week.

Because they're hinge joints, knees tend to be quite musical, especially in the weeks and months after surgery. Noises alone don't indicate a concern. Most commonly, knee sounds — whether your knee has been surgically repaired or not — are categorized as crepitus, including snapping, crackling, crunching, crinkling and popping sounds. Crepitus can result from the rubbing of cartilage on the joint surface or other soft tissues around the knee during movement. When knee snapping or catching is painful, that is usually a result of scar tissue, a meniscus tear or a tendon moving over a bony part within the knee joint.

Synovial fluid

A possible cause of a noisy knee is a buildup of fluid that naturally lubricates the joints (synovial fluid).


The patellofemoral joint — where your kneecap meets your thighbone (femur) — is typically the source of knee crepitus. Cartilage, the smooth, elastic tissue that covers the ends of bones, normally allows the bone surfaces to glide easily in the joint. But over time, the cartilage...