Synovitis is inflammation of any synovial membrane of a joint. Synovial membranes line joint capsules. A synovial membrane secretes synovial fluid to nourish cartilage and lubricate the joint.
Synovitis is common in arthritis. Symptoms may include pain when you move the affected part and swelling. If you have synovitis, your doctor may suggest or prescribe NSAIDs to control the inflammation and pain. Sometimes cortisone injections are given for synovitis.
Synovitis is often found at the sacroiliac joints when you have an inflammatory arthritis disease such as spondylitis. It is considered to be an active inflammatory lesion. For people with spondylitis, an MRI using one of several specialized techniques is generally necessary to find evidence of synovitis and other active inflammatory lesions.

