4. disease may cause the breakdown of joint tissues which decreases the functionality of the joint. Autoimmune joint disease is not as well recognized or as fully understood in animals as it is in human pathology; however recent and future studies endeavour to unveil the pathophysiology of such disorders. Other proposed causes include aging, mechanical instability and secondary to synovitis.
Joint Diseases
Synovitis/Capsulitis Synovitis is defined as the inflammation of the synovial membrane, where capsulitis is defined as the inflammation of outer fibrous joint capsule. Typically, these 2 conditions occur simultaneously. trauma to the joint capsule or the synovium itself. Acute trauma generally occurs when a joint area is kicked or hit during activity. Repetitive trauma occurs with joint instability or with repeated hyperextension and hyperflexion of a joint. In these cases, the delicate synovial membrane is pinched between the articulating surfaces of the bones or the synovium develops micro-tears when ligaments pull on the joint capsule. Synovitis/capsulitis is commonly caused by direct trauma or of the joint space is known to cause synovitis. The infective agents cause damage to the cells of the synovium leading to inflammation. Similarly, intra-articular injection of caustic or irritating substances is an iatrogenic cause of synovitis. No matter what the cause, the disease process for synovitis/capsulitis always follows the same pattern. Injury to or irritation of the cells of the synovial membrane, or injury of other structures found within the joint capsule, cause the release of inflammatory mediators such as prostaglandins, inflammatory enzymes and cytokines. These molecules cause the of the hyaluronic acid chains and the glycosaminoglycans that give synovial fluid it’s lubricating and shock absorbing properties. The synovium begins to produce large amounts of poor quality, watery synovial fluid in an attempt to compensate for the decrease in the protective abilities of the synovial fluid. conformation, exercise, especially work that causes high shearing forces, horses simultaneously affected by developmental orthopaedic disorders and geriatric horses. Predisposing factors for synovitis/capsulitis include poor joint Synovitis/capsulitis commonly occurs in the carpal joint, in the fetlock joint, in the stifle, in the hock joint and in the distal interphalangeal joint. A synovitis reaction may also be seen in synovial tendon sheaths (tenosynovitis) and in synovial bursas (bursitis).
Clinically, synovitis/capsulitis is seen as joint
, especially along the joint lines,
pain, decreased range of motion, lameness and heat in affected joints.
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