Tendonitis, is a painful condition of tendon irritation. Tendons are located throughout the whole body. They are flexible, rope-like tissue that connects muscle to bone. When upper extremity tendons become inflamed and irritated, symptoms such as pain and stiffness may be present (Fig. 1). In many cases, overuse can be a causative factor causing inflammation which over time can lead to tears in the tendon.
Tenosynovitis, unlike tendonitis, is an inflammation of the lining of the tendon sheaths that surrounds the tendons. Pain can be caused by motion of the tendon within the sheath. DeQuervain’s tenosynovitis is a common condition that affects the tendons at the base of the thumb and wrist. Over use and injuries can also precipitate symptoms. Systemic diseases, such as diabetes or rheumatoid arthritis may also play a factor in the development of tenosynovitis.