Trigger Finger or Trigger Thumb

Trigger finger or trigger thumb, also known as stenosing tenosynovitis, is a common condition which normally causes stiffness, pain, and a locking or catching sensation, especially when bending and straightening the finger. The flexor tendon that bends the finger or thumb enters a tunnel at the base of the digit. The tunnel that it enters is called the flexor tendon sheath and is composed of multiple pulleys. The first pulley in the pulley system is called the A1 pulley. The A1 pulley can become thickened and inflamed, and this results in a "catching" of the tendon as it glides through the pulley system. This causes the finger or thumb to get "stuck" in a certain position. With a little force, the finger or thumb then has to be straightened out. This is usually painful but not always. There is often a tender nodule at the base of the thumb or finger, which represents the thickened A1 pulley.

Signs and symptoms of a trigger finger or trigger thumb may include finger stiffness, a popping or clicking sensation when moving the finger, tenderness or bump at the base of the affected finger, and a finger or thumb that is locked in a bent position. These symptoms may progress from mild to severe.

Trigger finger or trigger thumb treatment is initially conservative, and the majority of these cases get better without surgery. This involves a corticosteroid injection around the A1 pulley which allows the flexor tendon to glide freely through the tunnel. Sometimes the injection doesn't cure the condition, and it wears off after weeks or months, and another injection is required. If conservative treatment does not work, Prof McGuire may then recommend a small operation to release the A1 pulley, which then allows the tendon to glide freely. This can be done under local or general anaesthetic and is usually a day procedure.