Inflammation of the tendon can lead to 'trigger feeling'

Have you ever had the disconcerting experience of being unable to straighten your finger after bending it? If you have, odds are you have a "trigger" finger.

A trigger finger is a finger that "locks" after it has been flexed (bent).

At times, you can't even straighten it out without the help of your other hand pulling at the offending finger. Some may even hear a loud "click" as the finger is straightened.

A trigger finger is also known as stenosing tenosynovitis in medical speak.

The phenomenon could affect one or more fingers, although it commonly afflicts the little and ring fingers, as well as the thumb.

And bad news for right-handers - it has been found to be more common in the right hand.

It is common for sufferers of the condition to experience pain and stiffness of the affected finger. Often, a small lump of tissue known as a nodule develops at the base of the affected finger.

Approximately two out of 100 people develop trigger finger. Nobody knows what causes it, but there are several factors that can increase one's risk. These include:

·Being a woman

·People over the age of 40 years

·Certain medical conditions

·People whose work or hobby requires repetitive gripping actions, such as musicians, gardeners and construction workers.

Conditions that can increase the likelihood of trigger finger include those affecting the hand, such as Dupuytren's contracture. This describes a thickening of tissues in the palm, and when it progresses, one or more fingers bend into the palm and cannot be straightened.

Long-term medical conditions such as rheumatoid arthritis, amyloidosis, diabetes, carpal tunnel syndrome and people on dialysis, can also trigger (excuse the pun) the condition.

In fact, around 10 per cent of people with diabetes develop trigger finger.

Although nobody knows what really leads to trigger finger, it is believed that some sort of inflammatory process is the culprit, with the inflammation leading to swelling of a tendon or its sheath.

In essence, a tendon is a tissue (fibrous cord) that is primarily responsible for attaching a muscle to a bone.

In the case of trigger finger, the tendon comes from a muscle in the forearm that passes through the palm and attaches to the finger bone.

When the muscle pulls on this tendon, the finger bends towards the palm.

A tendon sheath functions to protect the tendon.

Normally, as you bend and straighten a finger, the tendon slides easily in and out of the sheath. In trigger finger, the tendon can slide out of the sheath easily enough when you bend your finger.

However, it cannot slide back in easily (due to the swelling). The finger then remains bent.

The diagnosis of trigger finger is made almost exclusively by history and physical examination alone.

Around one in five cases will improve without any treatment. Simply resting the hand may resolve the problem without the need for treatment.

In certain cases, painkillers and non-steroidal anti-inflammatory drugs (NSAIDs) may be used to reduce swelling.

For some, splinting by strapping the affected finger to a plastic splint can be utilised to relieve pain and aid recovery. Some people wear the splint just at night. Splinting may be required for at least six weeks.

On occasions, corticosteroid injections are used to reduce swelling, thereby relieving symptoms. The steroid is injected into the tendon, and it is combined with a local anaesthetic to make the injection painless.

In recalcitrant cases, surgery on the affected sheath is carried out. It involves making a 1-1.5cm incision in the palm to perform a "release".

This is a relatively minor procedure that is generally used when other treatments have failed.

The release can also be achieved with the use of a needle, without the necessity of undergoing a "formal" operation.

This is the percutaneous technique. Studies have shown that the percutaneous technique can be as effective and safe as the conventional open method of surgery.

Following surgery, results are noticed immediately. However, with an operation, there is a small risk of some numbness to the finger.

Do not delay seeking formal consultation and treatment. If it is not treated early, the affected finger could become permanently bent, which will make performing everyday tasks difficult.

Early cases can be treated successfully without surgery.