Corticosteroid and hyaluronic acid treatments in equine degenerative joint disease. A review.

Degenerative arthrosis is perhaps the most common debilitating disease of performance horses. Treatment should be based upon a knowledge of the anatomy and physiology of normal joints and upon an understanding of the processes of degeneration and repair. These topics are briefly reviewed. Although rest is probably, the most beneficial therapy, physical and pharmaceutical treatments are often employed in an effort to speed recovery. The effects and relative benefits of intrasynovial injections of corticosteroids, hyaluronica cid, and Arteparon are considered in detail. Although local corticosteroid therapy is inexpensive and is effective in reducing lameness caused by degenerative joint disease, it is rarely indicated. Septic arthritis and "steroid arthropathy" are two serious sequelae. Whereas the incidence of the former may be avoided through careful technique, the latter effect is inherent in the action of the drug. The accelerated rate of joint destruction observed in steroid arthropathy is due to suppression of chondrocyte metabolism and thus the processes of cartilage maintenance and repair. Hyaluronic acid is present in the synovial fluid and within the matrix of cartilage. The commercial preparation is no approved for use in the United States, but it is commonly obtained from other countries. Although hyaluronate apparently does not function in the lubrication of cartilage surfaces, it may improve lubrication of soft tissues thus decreasing resistance to joint movement and lessening pain. Reports substantiate the effectiveness of hyaluronic acid in treating early cases of degenerative arthrosis despite the fact that the drug does not significantly promote cartilage healing. Arteparon, a polysulfated glycosaminoglycan, has been used in Europe for two decades in the treatment of degeneration joint disease and is currently being tested in this country. The drug is deposited within diseased cartilage and improves the functional properties of the cartilage as well as stimulates cartilage metabolism.