Trigger Finger

Trigger finger and trigger thumb, otherwise known as “stenosing tenosynovitis”, are conditions involving the flexor tendons and pulley of the fingers and thumb. Symptoms may include soreness at the base of the finger on the palm side of the hand, stiffness, or a problem with motion where the digit may lock or catch as it is flexed into the palm and may require use of the other hand to “unlock” or straighten out the digit.

Trigger finger (or trigger thumb) occurs due to a mismatch in the size of the flexor tendon and the pulley through which it runs. Flexor tendons are the cord-like “ropes” that run from the forearm and to the thumb and fingers on the volar or “palm side” of the forearm and hand. The flexor tendons permit flexion or bending of the thumb and fingers to make a fist and grasp objects. The pulleys form a tunnel through which the tendons pass as they enter into the hand so that the tendon can be held against the bone. The particular pulley involved in this process is known as the “A1 pulley”. In trigger finger (or trigger thumb), there is a size mismatch between the flexor tendon and the pulley such that they begin to rub against one another. This leads to progressive inflammation and can result in a nodule in the tendon that can be felt through the skin. Eventually, this results in the classic “triggering” where the finger locks or catches in flexion.

Diagnosis of a trigger finger (or trigger thumb) typically is based on evaluation by your surgeon. This examination will evaluate for the classic findings of soreness in the palm at the base of the finger, a palpable nodule within the tendon as the digit is bent and straightened, and possible locking or catching as the digit if flexed into the palm. These symptoms often happen when awakening in the morning or at night when people are more likely to curl their digits into a fist. Your surgeon also will evaluate for other unrelated problems that may have a similar appearance to a trigger finger. Typically, additional diagnostic testing such as X-ray, ultrasound, or MRI, is not necessary.

Initial treatments may include activity modifications during the day to avoid repetitive or forceful gripping, splinting to reduce flexion across the involved joint (particularly at night), and nonsteroidal anti-inflammatory drugs (NSAIDs). With early trigger finger these measures may help, but with more severe or long-standing trigger finger, these measures may help to reduce symptoms but not cure the underlying problem.

Corticosteroid (cortisone) injections are another non-operative treatment option. These injections can reduce inflammation and improve the size mismatch between the pulley and the tendon. Particularly with more mild trigger finger (or trigger thumb), this may result in complete resolution of symptoms. In some cases, a second injection may be needed for complete resolution. For individuals with diabetes or with more severe trigger finger, steroid injections may not relieve the symptoms.

If non-operative treatment does not resolve the symptoms, then surgery may be recommended. This involves making a small incision in the palm overlying the involved flexor tendon and pulley. The A1 pulley is cut to permit the flexor tendon to glide smoothly. Because there are multiple pulleys to each digit, there should not be long term problems with hand function from release of only the A1 pulley.

Typically after surgery, immediate movement of the involved digit is encouraged. The incision usually heals within a few weeks. At this point, most people have resumed all of their regular activities. However, particularly in individuals with a severe long-term trigger finger, there may be persistent stiffness due to contracture.

Be sure to see an experienced surgeon to treat this condition. Our fellowship-trained specialists at The Buncke Clinic in San Francisco treat patients with trigger finger from across the Bay Area and Northern California. Contact us to schedule a consultation.

Below are links for third party resources

American Society for Surgery of the Hand

American Academy of Orthopaedic Surgeons