The Knee Joint

Courtesy of the Arthritis Research Campaign.

Cartilage
Cartilage is an elastic tissue found on the end of bones in a joint. In a healthy joint it acts as a cushion between the bones to prevent bone-on-bone contact and provides a smooth surface between them for comfortable movement.

Synovium
The synovium, or synovial membrane, is a sac that surrounds the joint. Its main purposes are to provide protection to the joint and to secrete a oily substance called synovial fluid that lubricates the joint.

Bursa
Located not within but near the joint, the bursa is a fluid-filled sac. The fluid it secretes lubricates the movement of the muscle, namely muscle-muscle and muscle-bone movement.

Tendon
Tendons are fibrous bands connecting muscle to bone.

Ligaments
Ligaments are shorter fibrous bands that connect bone to bone. They make up the capsule surrounding the joint.