Trigger finger or thumb (also known as stenosing tenosynovitis) is a condition that causes a sensation of the finger ‘locking’ or ‘catching’ when bending and straightening. The finger then snaps into place, similarly to a trigger being pulled and released.
The condition is associated with feelings of stiffness and pain that can restrict movement. This can impact the ability to perform many every day activities, including those needed to perform certain work responsibilities. Trigger finger most often occurs in the ring finger, but can also affect other fingers including the thumb (trigger thumb). If the condition becomes severe, the finger may become locked in a bent position (rare).
What causes trigger finger or trigger thumb?
Flexor tendons are fibrous cords that attach forearm muscles to finger bones. They travel through the hand, and are surrounded by a protective sheath that allows them to glide smoothly as the fingers bend and straighten (pulleys). If pulleys within the flexor tendons get inflamed or swollen, irritation can occur that affects the tendon’s motion.
Risk factors that can cause trigger finger include:
- Overuse – Occupations or hobbies that involve repetitive hand use or prolonged gripping.
- Age – People between the ages of 40 and 60 are more at risk.
- Gender – Women more commonly develop trigger finger than men.
- Health issues – Such as diabetes or rheumatoid arthritis.
- Carpal tunnel surgery – Commonly, trigger finger iis found in association with flexor tenosynovitis and carpal tunnel syndrome.
What are the symptoms of trigger finger?
Signs of trigger finger may occur especially following a period of extensive hand use (such as pinching and grasping activities).
Symptoms may include:
- Tenderness and pain when stretching or bending the finger.
- A sore lump at the base of the finger where it joins the palm.
- Stiffness in the finger, especially in the morning.
- A popping or clicking feeling as the finger moves.
- The finger locking in a bent position then suddenly popping straight.
- A locked finger that you cannot straighten.
How trigger finger is diagnosed
Adelaide orthopaedic surgeon Dr James McLean will begin with a physical exam of your hand and fingers while discussing your symptoms with you. During the exam, Dr McLean will look for signs of tenderness of the flexor tendon, thickening or swelling of the tendon’s sheath, and ‘triggering’ as you bend and straighten your finger. This physical examination gives Dr McLean the information he needs to make a diagnosis, and X-ray tests are rarely indicated.
How is trigger finger treated?
The treatment for trigger finger or trigger thumb depends on the severity of the condition. Most of the time, treatment begins with resting the hand and steroid injections into the tendon sheath. Padded gloves or a splint can be used to keep the finger still. Sometimes, gentle stretching exercises may be useful in decreasing stiffness and improving range of motion. For those whose condition has advanced to painful proportions, certain anti-inflammatory medications or even corticosteroid injections may be administered to ease the pain.
What to expect from surgical treatment
If non-surgical treatment is not improving the condition, surgery is a good, permanent solution to consider. Surgical treatment for trigger finger or thumb is called ‘tenolysis’, most commonly known as ‘trigger finger release’. To perform this surgery, Dr McLean uses a minimally invasive method called key-hole surgery. Key hole surgery is a quick and effective surgery that offers numerous benefits including reduced risk of infection and faster recovery times.
The procedure is performed in an operating theatre, and is performed through a small incision in the hand skin crease. Specialised tiny instruments are inserted through this incision. Once the tendon is released, all instruments are carefully removed, and the wound is closed. The procedure itself takes less than 10 minutes; and patients go home the same day. The incision point remains covered with a special waterproof dressing that can be removed after a number of days.
Patients should avoid activities that put stress on the hand – such as heavy lifting or tight gripping) for approximately 2 weeks after surgery. Dr McLean will advise of a suitable activity schedule for each patient’s recovery.