People who are severely affected by rheumatoid arthritis, infection, overuse or injury may develop a condition that involves the long tendons on the back of the hand—called dorsal tenosynovitis, inflammation of the lining of the sheath that surrounds the tendon (the cord that joins muscle to bone). The problem produces a painless soft lump, but the tendon may tear making you unable to move the finger. Some patients need surgery to remove the inflammation surrounding the tendon.
Tenosynovitis caused by infection needs immediate treatment. Your health care provider will prescribe antibiotics. In some severe cases, emergency surgery may be needed to release the pus around the tendon. If there is no infection, a steroid injection may be used to decrease inflammation along the tendon sheath.
After you have recovered, do strengthening exercises using the muscles around the affected tendon to help prevent the injury from coming back.