One of the most common procedures performed on equine athletes is a joint injection. The number of therapeutics available for treatment of joint inflammation has increased in recent years. With a greater number of choices the success of treatment has improved. Deciding what medication(s), therapeutics, dose, frequency, etc. to employ depends on a number of criteria such as the degree of lameness, the severity of the condition of the joint, the veterinarian’s preferences and past experiences and economics.
Why do we inject joints?
Joint injections are used to treat inflammation of the joint leading to or caused by degenerative joint disease. Degenerative joint disease is one of the most common causes of poor performance and shortened competitive careers. Inflammation can lead to damage of the cartilage lining the surface of the bone and further degeneration of the joint. Degenerative joint disease often progresses unnoticed before lameness becomes obvious.
Joint injections are the most effective way we have of locally treating inflammation in the joint. Ideally they slow the progressive degeneration and often allow the horse to continue to perform with reduced discomfort for a longer period of time.
The most common medications injected are hyaluronic acid (HA) and steroids. HA is a natural occurring substance in joint fluid. It is very viscous and reduces friction like oil. Joint fluid becomes thin and watery with joint inflammation. HA helps joint fluid return to its normal thick, protective character.
There are a number of different steroids employed in joint injections. They are very potent anti-inflammatories and can actually help in protecting the cartilage of the joint from inflammation. Certain types of steroids can have negative effects on joints when used in high doses and/or too frequently.
Regenerative therapies basically use cells or cell products to help restore/heal tissues in the body. Veterinarians have been employing a number of regenerative therapies in joints such as IRAP, PRP and stem cells.
We have used IRAP on a number of horses who have not responded to typical injections of HA and steroids and patients who at risk with steroid use. It is a derived from the patient’s blood through a process of exposing the blood to a special tube, incubation for 24 hours and then spinning the blood in a centrifuge. Ultimately it produces 6 to 8 doses which can be frozen for later use. Typically we will inject 2 to 3 doses one to two weeks apart and then use as needed.
Pro-Stride is a newer product that combines IRAP and PRP. PRP (platelet rich plasma) is another blood derived product that concentrates growth factors helping fight inflammation and promote healing. Pro-Stride offers the advantages of a 20 minute processing time as opposed to 24 hours with IRAP. It can be used in the field and in most cases will have a positive effect on the joint for approximately a year.
Stem cells are cells derived from the body with the potential to convert to the type of tissue needed for repair of the injured area. They have been used in conjunction with surgery in the hopes to regenerate cartilage. Veterinary and human medicine are still in the early stages of employing this therapy.
There are a number of new options for prevention and treatment of degenerative joint disease even beyond the one ones mentioned above. They have given a greater ability to treat severe and more challenging cases than we have had in the past.