Trigger Finger (Stenosing Tenosynovitis)

How trigger finger happens

The flexor tendons that bend your fingers run through a series of tunnels called pulleys, which keep them close to the bone. The first pulley, the A1 pulley, sits at the base of the finger in the palm. Inflammation and thickening of the tendon or the pulley narrows the space, and a nodule may form on the tendon. As the finger bends, the nodule catches on the pulley and then pops through, causing the triggering.

Causes and risk factors

• age 40 to 60
• female sex
• diabetes: a major risk factor; often several fingers affected
• rheumatoid arthritis, gout and hypothyroidism
• repetitive or forceful gripping at work or hobbies
• carpal tunnel syndrome and carpal tunnel surgery
• Dupuytren's contracture
• in young children, trigger thumb is a separate condition, often noticed as a thumb that stays bent

Symptoms

• clicking, popping or catching when bending or straightening the finger
• a finger that locks bent and may need the other hand to straighten it
• stiffness, worse in the morning
• pain or tenderness at the base of the finger
• a small, tender lump (nodule) in the palm
• in severe cases, the finger stays locked bent

The ring finger, thumb and middle finger are most commonly affected. More than one finger can be involved.

Grading

Diagnosis

Diagnosis is made by examination: the doctor feels for a tender nodule at the base of the finger and watches the finger catch as you open and close your hand. X-rays or ultrasound are only needed if the diagnosis is uncertain or arthritis is suspected.

Treatment

Non-surgical

• Rest and activity changes: avoid repetitive gripping and use padded tools.
• Splinting: a splint that holds the affected finger's knuckle straight, usually worn at night or full-time for 6 to 10 weeks, helps mild cases.
• NSAIDs for pain, following the label.
• Gentle stretching and tendon-gliding exercises.
• Corticosteroid injection into the tendon sheath: relieves symptoms in roughly 50 to 70% of people, often after one injection. A second injection can be tried. Injections are less effective in people with diabetes and may temporarily raise blood sugar.

Surgery

Trigger finger release is recommended when injections fail, symptoms recur, or the finger is locked:

• Open release: a small incision in the palm under local anesthetic to cut the A1 pulley. Takes about 15 minutes, with a high success rate.
• Percutaneous release: the pulley is released with a needle through the skin, without an incision, in suitable fingers.

Recovery after surgery

• finger movement is encouraged immediately
• light use within days
• stitches removed after 10 to 14 days
• full recovery and grip strength in 3 to 6 weeks; some stiffness or swelling may last longer
• hand therapy may help stiffness

Complications

• recurrence after injection
• infection, nerve injury or bowstringing of the tendon after surgery (rare)
• persistent stiffness, especially if the finger was locked for a long time
• skin thinning or color change after steroid injection

Frequently asked questions

What causes trigger finger?

Trigger finger happens when a flexor tendon becomes swollen or develops a nodule and catches on the tight pulley at the base of the finger. It is more common in women, people over 40, and people with diabetes, rheumatoid arthritis or repetitive gripping activities.

Can trigger finger go away on its own?

Mild cases sometimes improve with rest and splinting over weeks to months. Many cases persist or worsen without treatment. A steroid injection cures many people, and surgery is very effective when other treatments fail.

How effective is a cortisone shot for trigger finger?

A corticosteroid injection relieves symptoms in roughly half to two-thirds of people, often with a single injection. It may be less effective in people with diabetes or long-standing symptoms. A second injection or surgery is an option if it returns.

How long is recovery after trigger finger surgery?

Most people use the hand for light tasks within a few days. Stitches come out after about 2 weeks, and full grip strength usually returns within 3 to 6 weeks. Some stiffness or tenderness may last a few months.

Is trigger finger related to arthritis?

Trigger finger is a tendon problem, not arthritis, but it is more common in people with rheumatoid arthritis and other inflammatory conditions. It can also coexist with osteoarthritis of the fingers.