Equine Joint Injections
Intra-articular injections are performed to sterilely deliver one or more pharmaceutical drugs or other products directly into the joint. The two most common reasons Dr. Garfinkel to perform a joint injection are to anesthetize or “block” a joint during a lameness examination or to medicate a joint to help keep the horse’s joints pain-free.
In addition to traditional anesthetics,antibiotics, and steroids, emerging therapies such as interleukin-1 receptor agonist protein (IRAP) therapy are being used increasingly for horses with joint diseases such as synovitis and osteoarthritis.
Joint injury, joint disease secondary to trauma or injury, and osteoarthritis (OA) are major causes of attrition and loss of function in horses. Treatment of these conditions is an important component of maintaining the overall health and mobility in pleasure and athletic horses, and joint injections play an important role in managing joint health in conjunction with other therapies such as nutritional supplementation,weight management, and non-steroidal anti-inflammatory drugs.
Intra-Articular InjectionsRegardless of the product being administered, the process of delivering intraarticular medications is essentially the same. The joint is cleaned with an antiseptic soap for approximately 10 minutes. The soap is rinsed off with isopropyl alcohol. Clipping the horse’s hair is often not necessary. The veterinarian then injects the desired drugs or products into the clean joint using sterile needles and syringes while wearing sterile gloves. Horses will require sedation.
Joint blocks using local anesthetics, such as lidocaine or carbocaine, are important tools during lameness exams to confirmthe anatomic structure(s) involved. For example, 15 to 20 minutes after the local anesthetic is injected in the joint, the horse can be reassessed to determine if its lameness has changed. If the horse has improved and is more sound after blocking, then the anesthetized joint is likely contributing to the lameness. Advanced diagnostics and/or treatment then can be undertaken.
Corticosteroids, hyaluronic acid, and polysulfated glycosaminoglycan (PSGAG) antibiotics are the most frequently administered intra-articular medications. Each of these drugs has a different mechanism of action, but they are all used to control inflammation (i.e., pain and swelling) and improve mobility. A small amount of antibiotic is sometimes injected along with the above-described medications for infection control purposes.