Beauty Forum Medical, Issue 02/2020
Dr. med. Karl Schuhmann is a specialist in Plastic/Aesthetic Surgery and Hand Surgery and answers the 7 most important questions about trigger finger.
1. What exactly happens when we talk about a trigger finger?
Dr. med. Karl Schuhmann: The flexor tendons of the fingers and thumb are encased in a tendon sheath and run through the annular ligaments. Inflammatory processes can lead to changes in the tendon sheaths and a thickening of the tissue. When trying to straighten the finger, there is a sudden "jerk" of the thumb or another finger. Similar to a jackknife, the affected finger snaps into the extended position. The trigger finger is also known as annular ligament stenosis, snap finger, spring finger, tendon constriction syndrome or tendovaginitis stenosans.
2. How does a snap finger develop?
The tendon sheaths are the covering of the flexor and extensor tendons at the hands and wrists as well as at the feet and ankle joints. The tendons in turn are strong, fibrous bands that connect the muscles of the forearm with the bones of the carpus, metacarpus and fingers. This system of muscles, tendons and tendon sheaths enables the smooth and fluid extension and flexion of the wrist and fingers. A trigger finger develops through a thickening of the tendon sheath. The annular ligaments keep the tendons in position. During bending and stretching of the finger, the tendon glides through the annular ligament. With a trigger finger or snap thumb, the tendon can no longer pass freely through the first annular ligament and gets stuck due to the thickening of the tendon sheath. When the tendon thickens in front of the annular ligament, the annular ligament can only be overcome with great force — that is, with a snapping motion.
3. What are the symptoms and who is affected?
Symptoms include a snapping of the finger when bending forward as well as difficulty straightening the affected finger. The condition can also be associated with pain and tenderness in the affected finger or the base joint of the hand. The condition affects women more often than men. Those predominantly affected are women over the age of 50. The thumb is most commonly affected, followed by the middle finger and then the remaining fingers. Swelling or fraying of the tendon causes painful friction in the area of the tendon sheath. In addition to pain, this can also lead to snapping; sometimes a finger gets "stuck" or is even completely blocked. In the final stage of the disease, the finger can only be straightened again with the help of the other hand. In the area of constriction, the finger is very sensitive to pressure. A thickening can be felt on the affected tendon.
4. What are the causes of a trigger finger?
The reasons for this condition are not fully understood. Chronic overuse or inflammatory thickening of the tendon sheath causes the trigger finger. Constantly repetitive activities, such as working with scissors, screwdrivers or other tools, gardening and housework, can lead to inflammation of the tendon sheath. Possible causes can also include hormonal changes, gout or other metabolic diseases such as diabetes mellitus. Systemic diseases such as rheumatoid arthritis or chronic polyarthritis can also be triggers.
5. How common is it?
Each year, approximately 28 out of 100,000 people are newly diagnosed with a trigger finger. Women are affected about six times as often as men. In diabetics, the likelihood of developing a snap finger is increased to ten percent.
6. What does the treatment look like?
The condition of trigger finger can be treated conservatively or surgically. Depending on the phase and severity of the condition, different therapies are used. If the snap finger has only existed for a short time, one can wait to see whether any irritation that may be present subsides again. This is best achieved first by resting the hand. The hand should definitely be protected from overexertion. This means that permanent activities should be avoided for several days. Ideally, the hand should be immobilised for several days. The administration of anti-inflammatory medication and massaging the painful hand and fingers can also provide relief. Cooling with quark wraps, cooling tinctures or creams as well as local ice application help against the inflammation and can thus contribute to pain relief. If conservative therapy does not lead to success or if the symptoms are already too severe, surgery should be considered. An operation for trigger finger is the most frequently performed surgical procedure in hand surgery. During an outpatient operation, the annular ligament is split and the thickened tendon sheath is additionally removed. The procedure is performed under local anaesthesia and takes approximately 15 minutes. Patients can go home immediately after the procedure. The hand should be kept above heart level for the first few days to avoid swelling. As early as one day after the operation, the patient can begin with light finger exercises for extension and making a fist.
7. What measures are there after the operation?
Extensive aftercare is generally not required. However, one should avoid placing excessive strain on the finger for approximately two weeks. Movement of the finger is important for healing. This means that light bending and stretching exercises should be performed daily. These exercises should also be started as early as possible after the procedure in order to prevent troublesome adhesions or even scarring of the operated tendon. Finger exercises also contribute to renewed strengthening of the muscles. The hand should always be kept higher than the elbow. At night it may be advisable to elevate the hand on a pillow. 12 to 14 days after the operation, the sutures can be removed. During this time, until the sutures are removed, one should shower or bathe with a protective cover. If necessary, physiotherapy and lymphatic drainage may be advisable. (ms)
