👉 Cage fluid, also known as intra-articular fluid, refers to the viscous liquid that lubricates and nourishes the synovial membrane within joint cavities. It is contained within a specialized bag, typically made of silicone or polyurethane, placed directly into the joint space. This fluid serves multiple critical functions: it reduces friction between the articular cartilage surfaces during joint movement, absorbs shock and distributes loads evenly across the joint, and provides essential nutrients to the cartilage. When a joint is injured or inflamed, the quality and quantity of cage fluid can be compromised, leading to increased friction, pain, and potential cartilage degradation.
