Work from home (WFH) arrangements are enabling more frequent and unrestricted use of digital devices, causing repetitive stress injuries such as trigger finger to occur.

Covid-19 cases are on the rise again, now with B1617, a new, more transmissible variant at large, prompting ASEAN countries to enforce stricter social-distancing and self-isolation measures. As we continue working from home, doctors are seeing a rise in repetitive stress injuries, such as trigger finger, due to indiscriminate use of digital devices during quarantine.

Brought on by overuse, age, and comorbidities, trigger finger is characterised by a snapping or jerking of the affected finger from a clenched position – much like how the trigger of a gun clicks when one pulls on it to fire, hence its name ‘trigger finger’. Considered a leading cause of hand pain and/or disability globally, it poses a 2.6% lifetime risk of development and is the fourth most common reason for referral to a hand surgery clinic.

How does trigger finger occur?

The hand’s flexor tendon is encased by a sheath comprising multiple pulley systems enabling you to bend your fingers and grip and lift objects. “If there is inflammation of the first annular pulley (A1 pulley), the tendon and A1 pulley may respectively swell and narrow, restricting the tendon, causing it to snap or jerk when you extend your finger,” says physiatrist, Dr. Norarit Luanchumroen, from Nopparat Rajathanee Hospital in Bangkok,

Although exact causes of trigger finger are unknown, it has several risk factors. “Those who use their hands frequently such as labourers and industrial workers are most affected, as repetitive movements such as gripping and lifting inflict microtraumas on the tendon and sheath,” shares Dr Luenchomroen.

In industrialised countries whose populace relies heavily on electronic devicestrigger finger is seen in those who type on keyboards and text on smartphones for many hours a week, hence its other name ‘texting tendonitis‘. Also an age and comorbidity related disease, trigger finger commonly affects patients in their 40 to 60s, as well as those with other conditions including, diabetes, rheumatoid arthritis, and hypothyroidism.

Disease stages

The usual, initial symptoms of trigger finger are tenderness and swelling at the base of the palmar side of the affected finger. As the condition progresses, patients may experience snapping sensations when they attempt to straighten the affected finger. If left untreated, a catching of the finger develops, where extension of the finger is only possible through passive force. At advanced stages, fingers may permanently lock in flexed positions.

“If patients have late-stage disease, the only feasible treatment option is surgical intervention, with patients still potentially experiencing stiffness even after surgery,” cautions Dr Luenchomroen.

Treatment of trigger finger

Trigger finger management begins with conservative methods such as rest/activity modification to eliminate risk factors and oral non-steroidal anti-inflammatory drugs (NSAIDS) to reduce inflammation. If symptoms persist, doctors may recommend splinting, physical therapy, or steroid injection beneath the sheath, which Dr Luanchumroen administers using ultrasound-guided techniques to ensure precision while minimising the dose.

Surgery is advocated when the condition does not respond to conservative treatments and if patients cannot avoid using their hands. These procedures, according to Dr Luanchumroen, are divided into invasive and minimally invasive techniques, each with its own pros and cons.

“Traditional open trigger finger release surgery, although effective in locating and releasing the A1 pulley, requires invasive methods and long downtime, with 20% of patients experiencing scarring, potentially leading to a relapse in the disease. Percutaneous trigger finger release, in contrast, is minimally invasive but involves a blind approach, possibly resulting in insufficient tissue release and injury to the surrounding structures,” warns Dr Luanchumroen.

Advantages of the ultrasound-guided percutaneous release procedure

To navigate these pitfalls, Dr Luanchumroen pioneered the ultrasound-guided percutaneous (meaning made, done, or effected through the skin)  release procedure based on the ultrasound-guided steroid injections. Combining diagnostic tools and minimally invasive techniques, this treatment involves locating the A1 pulley via ultrasound imaging and using a needle to penetrate the skin and release it. Since the procedure is not invasive, patients rarely experience prolonged healing, complications or side effects.

“Compared to the long downtime and scarring of open surgery and the ineffectiveness of a blind technique, the ultrasound-guided percutaneous release procedure has allowed my patients to regain use of their hands within two days, without noticeable scars. Plus, with the ultrasound imaging, affected pulleys are not only accurately located, damage to surrounding structures are also avoided, thereby offering a 99% release rate as well as a low recurrence,” says Dr Luanchumroen.


Featured photo by Dreamstime