Trigger finger, known medically as stenosing tenosynovitis, is a condition in which a finger or thumb becomes caught or locked in a bent position. It produces a characteristic clicking or snapping sensation when you try to straighten it. The condition can affect any finger and when it involves the thumb it is called trigger thumb.
Trigger finger is more common than many people realise. It tends to affect people between the ages of 40 and 60, is more common in women and is associated with conditions such as diabetes and rheumatoid arthritis. If you have noticed clicking, locking or pain at the base of a finger, you may be experiencing trigger finger.
What causes trigger finger?
To understand trigger finger, it helps to know a little about how the tendons of the hand work. The flexor tendons run from the forearm through the palm and into the digits, allowing you to bend your thumb, fingers and grip. These tendons pass through a series of tunnels called tendon sheaths and are held close to the bones by tight bands called pulleys.
In trigger finger and trigger thumb, the A1 pulley, which sits along the base of the digit at the level of the palm, becomes thickened and inflamed. As the tendon passes through this narrowed section, friction builds up and a small nodule often forms on the tendon itself. The nodule catches on the pulley when the finger is straightened, producing the triggering effect. In more severe cases, the finger or thumb can become locked in a bent position and cannot be straightened without using the other hand.
Trigger finger and trigger thumb can develop without any obvious cause, but contributing factors include:
- Repetitive gripping activities: manual work, gardening or sports involving sustained gripping.
- Diabetes: significantly increases the risk and can sometimes affect multiple digits.
- Rheumatoid arthritis: inflammation can affect the tendon sheath.
- Hypothyroidism: associated with tendon changes.
- Previous hand injury: particularly injuries to the palm, finger or thumb base.
What are the symptoms?
Symptoms of trigger finger and trigger thumb typically develop gradually and may include:
- Pain or tenderness at the base of the affected digit, particularly in the palm.
- A palpable nodule: a small lump felt in the palm at the base of the affected digit.
- Catching or clicking: a snapping sensation when bending or straightening the digit.
- Stiffness, particularly in the morning or after periods of inactivity.
- Locking: the digit becomes stuck in a bent position and requires the other hand to straighten it.
- Swelling at the affected joint.
How severe is trigger finger and trigger thumb? The four grades:
Trigger finger and trigger thumb are classified into four grades of severity, which guide treatment decisions:
- Grade 1: pain and tenderness at the A1 pulley, with a history of triggering but no triggering reproducible on examination.
- Grade 2: visible triggering on examination but the patient is able to actively straighten the finger.
- Grade 3: visible locking; the finger cannot be actively straightened and requires the other hand to extend it.
- Grade 4: a fixed flexion contracture; the finger is permanently locked in a bent position and cannot be straightened even passively.
Most people seek treatment at Grades 2 or 3. Waiting until Grade 4 can make treatment more complex as a fixed contracture may require additional intervention.
Is trigger finger or trigger thumb serious?
Trigger finger and trigger thumb are not a dangerous conditions, but they are progressive without treatment. Most cases will advance through the grades over time and spontaneous resolution is uncommon. A finger that catches and clicks today may become locked and painful if left untreated.
Early treatment is associated with better outcomes and a reduced likelihood of requiring surgery. If you have noticed symptoms of trigger finger or trigger thumb, an early assessment with a Hand Therapist is advisable.
What are the treatment options?
Hand Therapy and non-operative treatment
Non-operative management without surgery is effective for many cases of trigger finger, particularly at Grades 1, 2 and 3.
Splinting is a cornerstone of non-operative trigger finger management. A splint holds the affected finger in a specific position to prevent the triggering movement, allowing the inflamed pulley to settle. The type of splint used and which joint it immobilises depends on the digit affected and the grade of triggering. Ms Razo fabricates bespoke thermoplastic orthoses to precisely match each patient’s anatomy and presentation.
An important note on exercises: not all exercise is appropriate for trigger finger or trigger thumb. High-repetition active exercises and gripping tools such as stress balls or grip strengtheners should be avoided as they can aggravate the pulley inflammation and worsen the condition. Instead, Ms Razo will guide you through specific gentle exercises combining passive and active movement designed to improve mobility without provoking further irritation. Warm water immersion followed by slow gentle stretching can be helpful.
Activity modification is an important part of management. This means identifying and temporarily reducing the activities that provoke symptoms. It does not mean stopping all hand use, but making thoughtful adjustments to how and when you use the affected hand.
Corticosteroid injection
An injection of corticosteroid into the tendon sheath can be a highly effective treatment for trigger finger, reducing the inflammation of the pulley and allowing the tendon to glide more freely. Injections are typically given by a doctor and can produce significant lasting improvement, particularly in earlier grades. Some patients require more than one injection.
Injection is often used alongside Hand Therapy, either as an initial treatment or when rehabilitation alone has not fully resolved the triggering.
Surgery
For cases that have not responded to non-operative treatment and injection, or for Grade 4 fixed contractures, surgical release is the definitive treatment. The procedure involves dividing the A1 pulley under local anaesthetic, allowing the tendon to glide freely. It is a day-case procedure with generally excellent outcomes.
Post-surgical Hand Therapy is important to restore full movement, strength and function and to prevent stiffness following the operation.
How is trigger finger different from Dupuytren’s contracture?
Both trigger finger and Dupuytren’s contracture can cause the finger to bend towards the palm and both produce a nodule that can be felt in the palm. They are, however, distinct conditions.
The key difference is that trigger finger involves catching, clicking or locking. The finger can usually be straightened (at least in earlier grades) but does so with a snap or jolt. Dupuytren’s contracture, by contrast, causes a gradual progressive tightening of the tissue beneath the skin, drawing the finger into a fixed bent position without any clicking or triggering.
In advanced trigger finger (Grade 4), a fixed contracture may closely resemble Dupuytren’s contracture. If you are unsure which condition you have, a specialist assessment will clarify the diagnosis.
How can Hand Therapy help?
Ms Razo specialises in the non-operative management of trigger finger and trigger thumb, offering:
- Custom thermoplastic splint fabrication and fitting
- A guided exercise programme tailored to your grade of triggering
- Activity modification and advice on protecting the pulley during recovery
- Education on what to avoid and why
- Post-injection and post-surgical rehabilitation
If you have noticed clicking, catching or locking in a finger or thumb, early assessment is the best step. Ms Razo offers prompt appointments with no waiting list. Book a consultation or contact the clinic to discuss your symptoms.