M67: Other disorders of synovium and tendon

The group of disorders classified under other disorders of synovium and tendon involves various conditions that mainly affect the protective layers of the joints and the fibrous cords attaching muscle to bone. These disorders range from inflammation to fibrosis and include different types like tenosynovitis (inflammation of the tendon and its surrounding sheath) and synovial cysts (fluid-filled sacs near the joint areas). Infection, injury, overuse, or certain autoimmune diseases can cause these conditions. Symptoms often include pain, swelling, and difficulty in movement, and the onset may be gradual or sudden. The disorder progression can lead to increased discomfort or potential disability, depending upon the specific disorder and its severity. Most commonly, these conditions affect joints of the wrists, hands, knees, shoulders, and ankles. However, theoretically, any tendon or synovium in the body can be involved.