Trigger Finger and Thumb
This is a common hand condition that affects all age groups. To start it may just cause slight difficulty in bending the finger and there is pain on the palm. Later there may be stiffness and you may have to use your other hand to bend and straighten your finger. When the condition is fully established the finger gets locked in a bent position and snap may be felt or heard when this happens. The finger may be unstuck by the other hand. This may be painful. This is the triggering that gives the condition its name.
What causes the finger to trigger?
Trigger finger develops when the lining of the tendon in a finger or thumb becomes chronically inflamed and thickened. The tendon may form a knot or nodule which can be felt in the palm. The inflammation also involves the inner lining of the sheath that surrounds the tendon and therefore smooth movement of tendon becomes even more difficult. The result is trigger finger.
To help understand how this can happen, imagine your tendon is like a piece of thread. It extends from the muscle in your forearm to the tip of your finger. Beneath each joint of your finger there is a little sling that the tendon must move through just as thread moves through the eye of a needle. If there is a knot in the thread the thread will stick or stop. In the same way a tendon that is thickened or knotted will have trouble moving through a sling at the finger joint. The sling itself is also narrowed making the condition even worse and this keeps the tendon from moving smoothly.
What cause the inflammation?
Usually there is no known cause for the chronic inflammation. Repetitive activity may be responsible but it is not certain. There is a known association between other hand ailments such as Carpal Tunnel Syndrome, Ganglions and Trigger fingers.
Trigger finger affects people of all ages including infants who are brought to doctor with a locked finger or thumb. Once locked, infants are unable to unlock their finger and therefore the finger may remain in a locked position until correction is performed. The condition is most common in middle-aged women. People with Diabetes are also more likely to get the trigger finger.
Diagnosis of trigger finger is made with simple examination of the hand. Different options of treatment include;
Rest: In mild cases where triggering is not fully established and pain is improving, resting the finger from heavy activity may help the condition.
Injection: An injection of cortisone given in and around the tendon sheath reduces inflammation and thickening of the tendon. It is effective in resolving the condition in around two thirds of the cases. Sometimes more than one injection may be necessary.
Surgery: Surgery is recommended if other treatment fails or the condition has been present for a long time and well established. The procedure is done under local anaesthesia as a day surgery. The operation involves a small cut in the palm where the tendon sheath is released to allow the tendon to move freely. This is a low risk operation and complication such as infection and nerve damage are uncommon.
Full movement of the finger is allowed after the operation. The large bandage is exchanged with a small dressing in 48 hours and the stitches are removed 10 to 14 days later. The recovery is fairly swift and is complete within a few weeks. The results of the procedure are very good but triggering may occasionally recur. Chances of recurrence are higher in patients with multiple finger involvement and people with diabetes and rheumatoid arthritis.