WM 5ft 2 157cm B Cup Sex Doll Mel SuperLoveDoll 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 Non Surgical Knee Pain: Say Goodbye 2025 A gel injection for the knee is often used when the joint loses some of its natural lubrication, which can happen with arthritis or cartilage wear., The gel acts as a lubricant and shock absorber