The medical term for a common condition known as “trigger finger” or “trigger thumb” is stenosing tenosynovitis. The tendons that bend the digits pass through a series of pulleys, which hold the tendons close to the bones. Normally the tendons and the tunnel have a slick lining, allowing easy gliding of the tendons as they pass through the pulleys.
Trigger finger occurs when soft tissues that make up the first pulley or the sheath that surrounds the tendon becomes thickened, causing constriction around the tendon. Sometimes the tendon will develop a nodule where the finger joins the palm. This prevents the tendon from moving freely through the pulley, causing clicking, catching or locking of the finger as it bends and straightens. The more the tendon catches, the more irritation and swelling is produced. Sometimes, the finger will become stuck or “locked”, making it hard to straighten the finger on its own.
Causes of Trigger Finger
In many cases there is no clear cause, it usually occurs in people who are otherwise healthy, and in one or more digits can be affected at the same time. Trigger fingers are often associated with medical conditions such as rheumatoid arthritis, gout, or diabetes. Local trauma to the palm or base of the finger may sometimes be a factor.
- Finger sometimes will become stuck or "locked", making it hard to straighten the finger on its own
- Discomfort or tenderness at the base of the finger or thumb on the palm side of the hand
- Catching, popping, or clicking may be felt as the finger moves
- When the finger triggers or locks, it feels as though the problem is at the middle knuckle of the finger or the knuckle near the tip of the thumb
- Swelling or a small lump can develop
The doctor may recommend in mild cases, restricting activity related to the finger and resting to help solve the problem.
Certified Hand Therapists can custom fit splints for the affected finger. A splint that limits full motion of the finger or thumb can help decrease tendon irritation, especially when worn at night/when sleeping.
A session with hand therapy can provide instruction in activity modification, splinting options, and a specific home exercise program to address symptoms.
Over-the-counter pain relievers may help alleviate pain and inflammation.
A steroid is a strong anti-inflammatory medication that can be injected into the area and is often effective in relieving trigger finger/thumb permanently. This injection to the affected portion of the finger can provide short-term pain relief and reduced inflammation, when medication is ineffective or not an option.
If non-surgical forms of treatment do not relieve the symptoms, surgery may be recommended. A consultation with our hand surgeon can help decide the best course of treatment for you. Surgery allows the tendon to move more freely by widening the tunnel. This also prevents permanent stiffness.
Video courtesy of American Society for Surgery of the Hand
The pulley and tendon in a finger, gliding normally