Trigger Finger or Thumb is when the digit ‘triggers’ suddenly – it gets jammed or locked into a position (bent or straight), sometimes returning with a painful snap.
When the A1 pulley becomes inflamed or thick, the tendon cannot move freely through the tendon sheath, causing the digit to stick in one place.
The condition is also known as Stenosing Tenosynovitis and mostly commonly affects the ring finger and thumb. Over time it may cause the flexor itself to become inflamed or develop a small nodule, restricting movement further.
In a more severe case, the finger or thumb can become locked into a bent position and require manual movement using the other hand, to return it into position.
While causes of Trigger Finger and Thumb are not fully understood, there are factors which increase the risk of it developing:
It is often difficult to pin point a cause of Trigger Finger or Thumb, but it can follow periods of extensive hand use, particularly pinching or grasping.
Flexor tendons allow fingers to bend and straighten. These are cord-like structures that run from the forearm to the finger bones. Each has a tendon sheath (tunnel) to enable it to move smoothly, which is held to the finger bones with tissue known as ‘pulleys’. At the base of each finger, one of these is called the A1 pulley.
Early treatment will include a non-surgical approach and may include:
If nonoperative treatment does not provide adequate relief, surgery can be considered:
A minimally invasive and successful procedure where a needle is inserted to break up the tightened tissue around the tendon sheath.
A small incision in the palm to access the tendon sheath which is cut open to allow more space for the tendon to move. This is a highly successful procedure for recovering mobility.