Current Treatment Options for Refractory Osteoarthritis of Low-motion Joints in Horses

Osteoarthritis of the intertarsal and tarsometatarsal joints (bone spavin) is a common cause of lameness in all types of equine athletes; however, it is particularly prevalent among Western performance horses. Osteoarthritis of the proximal interphalangeal joint (high ringbone), although is less common among equine athletes, is also a frequent cause of lameness in several breeds. Osteoarthritis of these ‘lowermotion’ joints develops due to repetitive compression, torsion, and shear strain on the joints. The hallmarks of chronic osteoarthritis of the intertarsal, tarsometatarsal, and proximal interphalangeal joints are articular cartilage damage, joint capsule fibrosis, periarticular osteophytes, subchondral bone lysis, subchondral bone sclerosis, joint narrowing and ankylosis. Therefore, osteoarthritis of these joints is typically difficult to medically treat once the process is underway.