Promoting Synovial Fluid Production for Better Joint Health Knee Gel Injections (Viscosupplementation): Uses & Side Effects How to Increase Grease in Knees Naturally? 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 Could a SynVisc injection help your knee feel better? Fremont Orthopaedics, Riverton and Lander Wyoming