Trigger finger, medically known as stenosing tenosynovitis, is a condition that causes stiffness and a painful locking sensation in one of the fingers or the thumb. Symptoms include a popping or clicking sound when the digit is bent or straightened. The affected finger may also feel tender at its base, sometimes developing a small, firm lump in the palm.
The Mechanism Behind the Locking
The movement of your fingers is controlled by long cords called flexor tendons, which connect the forearm muscles to the finger bones. These tendons must glide smoothly through a tunnel-like structure within the palm and finger, which is held in place by a series of tissue bands called pulleys. The first of these, the A1 pulley, is located at the base of the finger where it meets the palm.
Trigger finger develops when the flexor tendon or the A1 pulley becomes inflamed and thickens, which narrows the space within the tendon sheath. This creates a mechanical obstruction, much like a thick rope trying to pass through a narrow ring. As the finger attempts to straighten, the thickened tendon gets caught at the entrance of the constricted A1 pulley.
This catching is what produces the characteristic popping or clicking sensation, and in more advanced cases, it can cause the finger to lock in a bent position. The repeated friction often causes a small nodule or swelling to form on the tendon itself. This nodule further exacerbates the problem, creating a cycle of inflammation and mechanical difficulty.
Prognosis: Can It Resolve Without Intervention?
The answer to whether trigger finger can resolve on its own is nuanced, depending largely on the severity and duration of the symptoms. For mild cases, particularly those caught early, the condition may indeed resolve spontaneously without formal medical treatment. Some research suggests that over half of adult trigger finger cases may resolve without intervention after a mean period of around eight months from the onset of symptoms.
The likelihood of spontaneous resolution is highest in the thumb, which has been observed to resolve without treatment in up to 72% of cases. When symptoms are mild, conservative strategies can be highly effective in encouraging resolution. These methods focus on reducing inflammation and friction to allow the tendon to glide normally again.
Specific self-care actions include resting the affected hand by avoiding repetitive gripping or forceful movements that aggravate the condition. Wearing a splint, typically at night, can help keep the finger or thumb extended, preventing the painful locking that occurs during sleep. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may also be used to manage pain and reduce the underlying inflammation. However, if the finger is frequently or permanently locked, the condition is less likely to resolve completely with only these conservative measures.
Medical Interventions for Lasting Relief
When conservative management methods do not provide sufficient relief, medical interventions become the next step, starting with corticosteroid injections. A corticosteroid, often mixed with a local anesthetic, is injected directly into the tendon sheath at the base of the affected finger. The steroid reduces the inflammation and swelling of the tendon and its sheath, allowing the tendon to glide more easily through the A1 pulley.
Corticosteroid injections can be highly effective, with success rates generally ranging from 79% to 84% after one or two injections. However, the relief may not be permanent, as recurrence rates hover around 20% to 33%. Factors such as diabetes, a high body mass index (BMI), and a high grade of the condition can reduce the long-term success of the injection.
If non-surgical treatments fail, or if the finger is severely and permanently locked, a surgical procedure known as A1 pulley release is often recommended. This procedure has a high success rate, typically between 90% and 100%. The surgeon makes a small incision, usually in the palm, to access and cut the thickened A1 pulley.
Cutting the tight pulley removes the mechanical obstruction, creating more space for the flexor tendon to glide without catching or locking. This procedure is generally performed on an outpatient basis under local anesthesia and takes only about 15 to 20 minutes. Patients are typically encouraged to begin gentle movement immediately after surgery to prevent stiffness, and recurrence of the triggering is rare once the pulley has been released.