Tendon sheath cysts – are cystic swellings that occur within the tendon sheaths of the joints and are a condition caused by degeneration of the connective tissue in the joint capsule, ligaments, and tendon sheaths. A tendon sheath cyst is a cystic swelling. Some tendon sheath cysts originate from the tendon sheath, but more tendon sheath cysts originate from the joint capsule. The cyst contains a colorless, clear or orange, yellowish, thick mucus with a dense, hard, fibrous connective tissue wall. Patients are mostly young adults, and women are more common. They occur on the palm and dorsal side of the fingers, the dorsum of the wrist and the back of the foot. They often appear as superficial, well-defined, smooth-surfaced hemispheric masses. The onset of the disease is slow, with a round mass of medium quality that can be pushed, with slight soreness and pain, and swelling or radiating pain when pressed. The etiology of the disease is not clear, but it may be related to chronic trauma. It can be caused by injury, excessive strain (especially in the hands and fingers), osteoarthritis, some systemic immune diseases, or even infection. Some occupations that require long-term repetitive joint activities, such as typists, cargo handling, or industries that require long hours of computer operation, can cause or aggravate the disease. Commonly affected areas are wrists, fingers, shoulders and other locations, women and diabetic patients are more likely to suffer from this disease. Clinical manifestations 1. General symptoms Tenosynovial cysts can occur at any age, mostly in youth and middle age, more women than men. The cysts are slow growing, round, and generally do not exceed 2 cm in diameter. There are also sudden discoveries. In a few cases, they may subside on their own or grow back. In some cases, except for the local swelling, there is no conscious discomfort and sometimes mild pressure pain. Most cases have localized soreness or discomfort that affects activity. The size of the cyst is not directly related to the severity of symptoms, but to the tension of the cyst, the greater the tension, the harder the swelling and the more obvious the pain. 2.Local symptoms When examining, a round mass with smooth shape and clear boundary can be felt, the skin on the surface can be pushed, there is no adhesion, and there is soreness and swelling or pain when pressing. Most of the cysts have higher tension and tough masses, a few are soft, but all have cystic sensation. The roots of the cysts are fixed and there is little movement. (1) Tenosynovial cysts in the wrist Most occur on the dorsal side of the wrist and a few on the palmar side. The best site of occurrence is at the dorsal carpal joint capsule on the radial side of the common extensor tendon, followed by between the radial carpal flexor tendon and the long thumb extensor tendon. Cysts may also occur in the flexor tendon sheaths within the carpal tunnel, compressing the median nerve and inducing carpal tunnel syndrome. A few tendon sheath cysts can occur on the flexor tendon sheaths of the fingers far from the metacarpophalangeal joint, which are as hard as cartilage and the size of a grain of rice. (2) Tendon sheath cysts in the foot and ankle Tendon sheath cysts in the dorsalis pedis are more common and mostly originate from the tendon sheath of the long toe extensor tendon lateral to the dorsalis pedis artery. Tendon sheath cysts in the tarsal canal can compress the tibial nerve and are a cause of tarsal canal syndrome. Ultrasound examination can determine the nature of the mass (local mass ultrasound). x-ray radiographs can determine whether there are changes in the surrounding bones and joints. Diagnosis is usually established based on history, general and local symptoms of clinical presentation, and ultrasound examination. Treatment A few tendon sheath cysts can subside on their own, but there are some patients who are treated by various methods and still have recurrent attacks. 1.Non-surgical treatment Although the recurrence rate of conservative treatment of tendon sheath cyst is high, but this kind of method is the least traumatic and easy to be accepted by patients, so it can be the first choice of trial treatment method clinically. The tendon sheath cyst can be ruptured by extrusion and gradually absorbed by itself, but it may recur after treatment. Those connected with joint cavity are not easy to rupture, so puncture can be used to extract the cyst fluid, then press and rub, or inject adrenocorticotropic hormone or hyaluronidase after extracting the cyst fluid, and local pressure bandage for 2 days, which has certain efficacy. 2.Surgical treatment When other methods of treatment are ineffective, the tendon sheath cyst can be surgically removed. After surgery, avoid strenuous activities of the affected joint to prevent recurrence. Prevention 1, hand holding the mouse for too long, or incorrect posture, easy to lead to injury to the synovial cavity of the hand joint, thus triggering tendon sheath cysts. Therefore, the need to use the computer and the mouse for a long time office workers, should rest every hour for 5 to 10 minutes, do soft exercises or local massage. 2, you can do some gentle hand exercises to relieve pain. Rotating the wrist is one of the simple exercises. Rotate your wrist for about 2 minutes. It can exercise all the wrist muscles, restore blood circulation and eliminate the bending posture of the wrist. 3. Apply hot water to the affected area after exertion to allow local blood flow. Local massage is also good for promoting blood circulation.