Hyaluronic Acid Injection TKR Joint lubrication in an artificial knee joint Joint Replacement Patient Forum Joint fluid fills the small space between the ends of bones and acts like a natural lubricant. The synovial membrane creates this thick, silky fluid using long molecules that hold water and give it a Knee Osteoarthritis DID YOU KNOW? Movement nourishes your joints by stimulating synovial fluidyour body's natural joint lubricant. Just 2030 minutes of walking daily can make a big difference in your joint health, mobility, and Viscosupplementation: How Gel Injections Restore Your Knee's Natural Cushioning Joint Relief Institute