Trigger finger and thumb

What is a trigger finger?

Trigger finger (also known as stenosing tenovaginitis) is a common, often painful condition that can affect any of the fingers or thumb.  It is not thought to be an inflammatory condition, but may be due to degenerative changes affecting the flexor tendon sheath and surrounding tissues.

Figure 1: Typical position of a trigger finger when it has 'locked'

Symptoms:

The classical symptoms of a trigger finger include;

  • pain experienced in the palm at the base of the finger or thumb
  • episodes of 'locking' of the digit in flexion ( figure 1 ). This locking usually occurs after making a fist and the finger remains held in flexion and it is difficult to actively straighten the digit.  The finger can usually be extended by the other hand, the finger straightening with a snap (the so called 'trigger') which is frequently associated with pain. 

Not everyone experiences classical symptoms and there is some variability. Some patients can describe;

  • pain at the back of the finger over the proximal interphalangeal joint (the first finger knuckle joint)
  • feelings of 'clicking' or that the joint is 'dislocating' on movement.

Your surgeon will usually make the diagnosis clinically and further investigations are usually unnecessary. 

Figure 2: Video clip of a trigger thumb.

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Figure 3: Video clip of a trigger finger.

Treatment of trigger finger:

Non-operative:

In some instances improvement in symptoms can be made by wearing a splint, taking oral anti-inflammatory medication or having a cortisone injection into the flexor tendon sheath.  These treatments are less invasive than surgery and may only provide temporary improvement in the symptoms

Operative:

Surgery is indicated if the finger is in a permanently flexed position or if non-operative treatment is unsuccessful.  People may choose operative treatment primarily as it has a more predictable outcome.  Surgery is a relatively minor operation which is performed under local anaesthesia as a day case.  A small incision is made on the palm of the hand at the base of the finger or thumb where the surgeon will release the narrowing.   This relieves the constriction of the tendon as it passes through the sheath and stops the triggering.  It is a relatively minor procedure taking approximately 10 minutes on average.  Following surgery a light dressing is applied to protect the wound but allow early active movement of the fingers and thumb.  The dressing will remain for up to two weeks after the operation and it is recommended that the hand is kept dry during this period.

Recovery:

The operation is usually well tolerated and symptoms of locking are usually relieved immediately after surgery.  Patients can expect discomfort from the incision for 4 - 6 weeks and discomfort from deep pressure for as long as several months.  It is expected that a full recovery will be achieved within a few months after the surgery.  Most people can return to their normal activities within 2-3 weeks of the surgery, although some people may restrict heavier activities for 4-6 weeks.

Complications of surgery:

These are uncommon and usually minor:

  • wound infection (1%)
  • temporary scar tenderness (the most common problem).
  • finger stiffness or nerve injury (very uncommon, and usually temporary)