Gel injections (also called viscosupplementation) are used to treat joint pain from arthritis, especially in the knee. The gel acts as a lubricant and shock absorber inside the joint, helping reduce friction, Viscosupplementation Treatment for Arthritis Johns Hopkins Medicine Best Joint Pain Treatment: Your One Stop Guide Performance Lab A gel injection for the knee helps improve joint lubrication when natural synovial fluid becomes thinner or less effective, which often happens with arthritis., This gel acts as a cushion and