What is a trigger finger?
The bending movements of our fingers are controlled by muscle tendons called flexor tendons. These tendons travel down our forearms, wrists and palms to reach our fingers. At the fingers, the flexor tendons go through a series of ligament-like structures called pulleys, which help to position the tendons flat against the bones of the fingers. The A1 pulley is the one affected in most cases of trigger finger, although the A3 pulley has been known to be occasionally affected as well.
With frequent, repetitive and/or forceful use of our hands in daily activities (e.g. housework that requires frequent wringing dry of cleaning cloths/mops, cooking/baking activities, assembly line work, technical work that requires frequent use of hand tools, life events such as moving house), finger tendons may become strained over time, resulting in inflammation of the tendon and/or pulley. This can cause either swelling of the tendon (also called a nodule) and/or thickening of the A1 pulley, making it difficult for the tendon to glide though the pulley smoothly. A catch of the finger thus occurs when trying to straighten it from a bent position, which is often accompanied by pain over the base of the finger where the A1 pulley is located.
How common is trigger finger?
Trigger finger is the fourth most common reason for a referral to an orthopaedic or hand surgery clinic, with a lifetime risk of 2.6% among the general population. The average age on onset of the disorder is 58 years, with women being diagnosed with it 2 – 6 times more frequently than men. The thumb and ring finger of the right hand have been found to be the digits most commonly affected. Individuals with a medical history of diabetes, rheumatoid arthritis, gout, carpal tunnel syndrome, De Quervain’s disease and hypothyroidism also appear to be at higher risk of developing trigger finger. Forceful and repetitive overuse of the hand and fingers have also been thought to contribute to the development and subsequent aggravation of trigger finger symptoms.
What are the signs and symptoms of trigger finger?
Individuals affected by trigger finger are often unable to pinpoint a specific incident or injury that caused the onset of symptoms. Rather, symptoms tend to occur and worsen gradually after a period of heavy or extensive hand use in activities that require forceful and often repetitive gripping or pinching of the fingers or thumb.
Symptoms of trigger finger include:
- A lump or swelling at the base of the finger/thumb on the palm side of the hand which may be painful or tender when pressure is applied over it.
- During finger/thumb movements, the finger/thumb becomes stuck in a bent position and a greater amount of force is required to straighten it out. This may result in a “clicking” or “popping” sensation when opening up your finger/thumb, and may also be accompanied by pain.
- Feelings of stiffness over the affected finger/thumb (especially upon waking up in the mornings), which may result in an inability to form a full fist.
- In severe cases, the affected finger/thumb may become permanently locked in a bent position and surgery is often required to help straighten it out again.
How can trigger finger be treated?
Treatment for trigger finger includes both non-surgical and surgical options. Non-surgical treatment options are usually effective for trigger finger cases that are mild to moderate in severity, while severe cases of trigger finger will likely require surgical interventions. It is important to seek early treatment for trigger finger as non-surgical treatment success rates tend to decrease as more time passes before the start of treatment (severity of trigger finger may worsen with time).
Non-surgical Treatment Options
Trigger finger cases that are mild to moderate in severity often respond well to non-surgical treatment, which largely involves resting of the affected finger/thumb to allow the inflammation to subside naturally and specific exercises to prevent or alleviate finger/thumb stiffness. Your doctor may refer you to an occupational therapist, who will be able to provide the following services:
- Advice on lifestyle and activity modifications so as to eliminate or minimize daily activities or finger/thumb movements which may further aggravate the condition (e.g. heavy housework, lifting of heavy loads, active/repetitive/forceful gripping or pinching activities).
- Provide a customised splint to be worn over the affected finger/thumb when you are using your hands to perform daily activities so as to provide support and encourage further rest of the finger/thumb. Resting will help reduce inflammation and its associated symptoms (i.e. pain and triggering over the finger/thumb).
- Teach appropriate range of motion and stretching exercises that can help reduce finger stiffness while avoiding aggravation of trigger finger symptoms.
- Use of therapeutic modalities such as heat treatment and ultrasound therapy, which may provide temporary relief of trigger finger symptoms.
Other non-surgical interventions your doctor may prescribe include:
- Short-term oral medications (e.g. non-steroidal anti-inflammatory drugs) to help reduce inflammation and pain.
- Corticosteroid injections over the site of inflammation which can also help reduce inflammation, pain and triggering over the involved finger/thumb. These injections are usually done a maximum of two times over the same finger/thumb. If trigger finger symptoms still persist after two injections, surgery may be considered.
Surgical Treatment Options
Surgical interventions to help relieve trigger finger symptoms may be recommended in the following situations:
- The symptoms of trigger finger do not improve over time with non-surgical interventions.
- Trigger finger symptoms have been present for prolonged periods of time (i.e. more than six months) and has been diagnosed to be severe in nature (e.g. the finger or thumb has become stuck in a bent position and you are no longer able to straighten it on your own).
The surgical procedure for trigger finger is called a “trigger finger release or tenolysis”. During this procedure, a small incision is made over the palm at the base of the finger/thumb. The A1 pulley of the affected finger/thumb is then cut, “releasing” the tendon and opening up more space for the tendon to glide through during finger/thumb movements. As there are multiple pulleys present along the finger, releasing a single pulley (the A1) should not affect finger/thumb function in the future.
Recovery from trigger finger release surgery can take anywhere from several weeks to several months. Occupational therapy is often required after surgery to help regain the movement, strength and function of the affected finger/thumb.
Even after your trigger finger/thumb has recovered from non-surgical interventions (i.e. therapy and/or steroid injections), there is still a risk of it recurring if you continue using your hands to perform strenuous activities frequently. As such, precautionary measures should be considered when performing daily activities (e.g. household chores, cooking/baking activities, work tasks) to avoid the recurrence of previous trigger fingers and prevent the development of new trigger fingers. These measures include:
- Lifestyle modifications to avoid or minimize activities that require repetitive and/or forceful gripping and pinching (e.g. wringing dry a wet washcloth, wringing dry a wet mop, kneading of dough during baking, carrying of heavy loads or bags, squeezing of brake levers while cycling, gripping of the steering wheel while driving, serving food with tongs).
- Use larger upper limb joints to carry loads instead of using your fingers (e.g. hanging a bag of groceries over your elbow instead of carrying it with your fingers).
- Take frequent short rest breaks (every 20 to 30 minutes) when performing strenuous activities, household chores or work tasks to allow adequate rest of your hands.
- Practice activity pacing to prevent overstrain of your hands and wrists (e.g. plan to perform strenuous activities, such as household chores and grocery shopping trips, over a few days instead of completing everything on a single day).
- Once you start feeling any pain or strain over your thumb or fingers, rest them well over the next few days. Early detection of strain and adequate rest of your hands are often the only things you need to keep trigger fingers away!
American Academy of Orthopaedic Surgeons. (2018). Trigger finger. Retrieved May 31, 2021, from https://orthoinfo.aaos.org/en/diseases–conditions/trigger-finger
Brozovich, N., Agrawal, D., & Reddy, G. (August, 2019). A critical appraisal of adult trigger finger: pathophysiology, treatment, and future outlook. Plastic and Reconstructive Surgery. Retrieved May 31, 2021, from https://journals.lww.com/prsgo/fulltext/2019/08000/a_critical_appraisal_of_adult_trigger_finger_.18.aspx
Langer, D., Maeir, A., Michailevich, M., & Luria, S. (January 10, 2017). Evaluating hand function in clients with trigger finger. Occupational Therapy International. Retrieved May 31, 2021, from https://doi.org/10.1155/2017/9539206