One shot cure for trigger finger

Three years ago, Mr Lim Ho Soon's third finger on his right hand began to hurt and swell a little.

It would also get stuck in a bent position and required a lot of effort to straighten. Finally, he saw a hand surgeon, who recommended surgery which fixed his condition.

But the experience did not help him recognise the issue when similar symptoms started appearing in his left hand about a year ago.

The swelling, stiffness and pain that afflicted the second and fourth fingers on his left hand started out mildly. The swelling would ease after he rubbed and massaged the areas.

He attributed it to ageing. "When you grow older, aches and pain will appear anywhere in your body," he said in Mandarin.

The 66-year-old part-time cleaner continued to treat the swelling and stiffness himself for months. But the pain got worse. "As it became more and more painful, I found it difficult to use that hand," he said, adding that his affected hand would hurt at the slightest touch.

When he finally saw a doctor, surgery was his only option to try and release the contracture of his fingers.

Mr Lim had trigger finger, so-called because the finger clicks or pops when the finger is straightened is much like the trigger of a gun being released, said Dr Darryl Chew, a consultant at the department of hand surgery at Singapore General Hospital (SGH).

Usually, bending and straightening of the fingers occur smoothly. When a person has trigger finger, the finger becomes locked in a bent position. It is only after using more force that the finger "snaps" or "pops" back into a straight position, said Dr Chew.

It is a very common condition - with a lifetime risk of 2 to 3 per cent - which affects more than a thousand people here a year. And with an ageing population, at least one hospital here is seeing more cases every year.

Dr Alphonsus Chong, head and senior consultant at the department of hand and reconstructive surgery at National University Hospital (NUH), said there has been about a 30 per cent increase in the number of patients seen between 2010 and last year for this condition. The hospital gets an average of 590 new cases a year.

At SGH, the department of hand surgery sees about 15 to 20 newly referred patients a week, adding up to about 800 new patients a year.

Most of them can be helped with massage, deep heat rubs or steroid injections.

Those whose conditions persist or worsen are offered surgery.

DANGERS OF WAITING TOO LONG

What worries doctors is that many patients, such as Mr Lim, wait too long before seeking help.

At NUH, about 20 per cent or one in five patients have symptoms for more than six months before they go to a doctor, said Dr Chong.

A paper by the SGH's department of hand surgery published last year reported that out of 153 patients studied, 26 per cent had symptoms of trigger finger for six months or more before seeing a doctor.

Patients tend to dismiss it as a trifling matter that will spontaneously resolve and, in minor cases, it might, said Dr Chong.

However, it often persists and when surgery is offered, some patients refuse it because they are concerned about the risks and complications, he said.

Unfortunately, delaying surgery just means more pain and inconvenience. "Imagine having pain every time the finger is bent and straightened. And that occurs with just about every activity," said Dr Chew.

In the late stages of triggering, the finger locks in a bent position and develops a contracture, meaning that it will have a permanent bend.

Surgery at that point may remove the triggering, but it cannot correct the bent position of the joint completely, said Dr Chew.

The joint will be permanently stiff and the person may not be able to straighten his finger fully despite intensive therapy, he added.

Despite it being a common condition, the exact cause of trigger finger is not known. It is believed that repetitive forceful finger movements, such as heavy lifting and gripping, contribute to its development, said Dr Chew.

But it is difficult to prove as everyone uses his hands to perform many activities at work, home and play, he said.

Trigger finger may also be associated with diabetes mellitus, gout and rheumatoid arthritis.

Those with diabetes have a higher lifetime risk of getting trigger finger - about 10 per cent - and their recurrence rate after receiving steroid injections is higher than for the general population.

Such injections are usually prescribed as an initial treatment for the condition.

POSSIBLE CULPRITS

One of the reasons that more people here are getting trigger finger could be the more frequent use of the computer mouse and typing on the keyboard and mobile devices, said Dr Lim Beng Hai, director and senior consultant hand surgeon at Paragon Medical Suites.

Texting could contribute to triggering involving the thumb rather than the other fingers, he said, as most people use their thumbs to type messages on smartphones, for example.

The condition usually occurs in people aged 50 to 60, but due to texting and increased use of the computer and mouse, doctors are now beginning to see younger patients being affected by this malady, said Dr Lim, who is also a visiting consultant at NUH.

It is also six times more common in women than men, possibly because women tend to do more housework. Household chores which could aggravate the problem include wringing out cleaning cloths or mops, hanging out clothes on bamboo poles or carrying heavy grocery bags.

HOUSEWORK WOES

Madam Koh Sway Muay, 69, is one such a patient.

The former primary school teacher retired about 12 years ago and has been keeping herself busy doing chores at home. Several times a week, she hangs her wet laundry out to dry on bamboo poles. She has to lift the heavily laden poles, hoist them outside of her HDB flat window and insert them into the pole holders.

"I think maybe doing that too often could have caused my finger to act up," she said.

"But I like drying my clothes the old-fashioned way, under the sun, even though I have a dryer at home."

Madam Koh's problem started last December when she noticed her right middle finger was a little bent. It would straighten after she rubbed it.

Then it became painful. She went to a general practitioner, who gave her a steroid injection.

"It worked very well. After two or three days, my finger and hand were back to normal," she said.

The problem returned in February and she went back to the same doctor, who gave her another injection. Again, it worked.

But in April, her finger became swollen, taut and painful. She did not want any more injections, so her doctor referred her to SGH.

"When I saw Dr Chew, my condition was very bad. My finger was bent at a 90-degree angle and could not be straightened at all," she said.

It was difficult for her to wash her face as she kept poking it with her trigger finger, and it was nearly impossible for her to hold a cup or write.

Dr Chew offered her surgery.

"I thought, 'Why not? If the surgery can cure it once and for all, instead of having to see the doctor every two to three months'," said Madam Koh, who had the procedure done last month.

She was also taught a few exercises to do at home. One of these involves putting her affected hand on a hard surface and using the other hand to press it straight.

"This helps to keep the joint from permanently contracting. When a finger has been locked in a bent position, it is very hard to keep the joint supple while waiting for it to recover," explained Dr Chew.

Patients also tend to keep their fingers in a flexed position because it is more comfortable.

"My hand is now 95 per cent back to normal. I am doing my exercises to get it back to 100 per cent," said Madam Koh.

How trigger finger develops

The tendons that move the fingers are held in place on the bones by a series of ligaments called pulleys.

The pulley is a structure that hugs the tendon close to the bone. Its function is to increase the efficiency of finger flexion. It is similar to the rings on a fishing rod. The rings keep the fishing line close to the pole and prevent it from sagging.

The tendon glides inside the sheath. The muscle is in the forearm. When the muscle contracts, it pulls the tendons, which are like strings. The tendon slides within the sheath and pulls the finger into flexion.

In trigger finger, when the finger is extended, the thick and tight pulley catches on the tendon nodule as the tendon tries to slide through it (above).

The nodule gets stuck, causing the finger to lock in a bent position. When more force is applied to extend the finger, the nodule pops through the pulley (right), causing a triggering effect.

During trigger release surgery (left), the tight pulley is slit open and the obstruction to smooth tendon gliding is removed.

This surgery is done as an outpatient procedure, under local anaesthesia, and takes about 15 minutes. There will be a wound that needs to be dressed for around two weeks, and the finger will be sore for two to three months.

Source: Dr Darryl Chew, consultant at the department of hand surgery at Singapore General Hospital

This article was first published on June 11, 2015.
Get a copy of Mind Your Body, The Straits Times or go to straitstimes.com for more stories.