ORTHOVISC® is a sodium hyaluronate solution that is sterile and non-pyrogenic. ORTHOVISC® can treat joint issues such as osteoarthritis by acting as a viscoelastic supplement or a replacement for synovial fluid in the joints. Normally sodium hyaluronate acts as a lubricant for tissues and a viscoelastic support in the spaces between tissues of the body, and it is thought to modulate interactions between tissues. To provide lubrication and mechanical support for joints affected by osteoarthritis, first remove any joint effusion, then inject ORTHOVISC® into the affected joint. Medical personnel should determine the correct volume of ORTHOVISC® to inject, making sure the joint is not overfilled. Usually this volume would be less than 2 ml for the knee or other larger joints, and less than 1ml for smaller joints. The treatment schedule for ORTHOVISC® is one injection a week for a total of three injections, no more often than every six months in any particular joint. Only physicians should purchase ORTHOVISC®, as well as use or supervise the use of ORTHOVISC® by qualified medical personnel.