Trigger Finger (Stenosing Tenosynovitis)

Trigger finger is a condition in which one of your fingers or your thumb catches in a bent position. Your finger or thumb may straighten with a snap — like a trigger being pulled and released. If trigger finger is severe, your finger may become locked in a bent position.


Trigger finger is a type of tendinitis which develops in the tendons which bend the fingers. It is a common problem because of the way that the hand is made, which may be a little different than you would suspect. There are no muscles in the fingers themselves. We actually move our fingers by remote control. Muscles in the forearm are connected to the finger bones by smooth, flexible strings, called tendons. The muscles pull on the tendons, which then bend the finger joints.

Often painful, trigger finger is caused by a narrowing of the sheath that surrounds the tendon in the affected finger. People whose work or hobbies require repetitive gripping actions are more susceptible. Trigger finger is also more common in women and in anyone with diabetes and rheumatoid arthritis.

Causes.

Tendons that control the movements of the fingers and thumb slide through a snug tunnel of tissue created by a series of pulleys that keeps the tendon in place. The tendon can become irritated as it slips through the tunnel. As it becomes more and more irritated, the tendon may thicken, making its passage through the tunnel more difficult. The tissues that hold the tendon in place may thicken, causing the opening of the tunnel to become smaller. As a result, the tendon becomes momentarily stuck at the mouth of the tunnel as the finger is extended. A pop may be felt as the tendon slips past the tight area. This why pain and catching may be felt as the finger is moved.

What can you do to help?

* Ice for five to fifteen minutes at a time on the area which is most swollen and tender.

* "Over the counter" non-steroidal anti inflammatory medication (NSAID), such as aspirin, ibuprofen, naprosyn, or ketoprofen. Check with your pharmacist regarding possible side effects and drug interactions.

* Avoid activities which involve a sustained grip. Hold off on the use of grip strengthening devices or exercises involving repetitive squeezing - these put stress on the irritated tendon.

* If fingers bend and lock during the night and are painful to straighten in the morning, it may be helpful to wear a splint to keep them straight while sleeping. One way to do this is to use a wrist support splint as shown below: A wrist splint designed to be worn on the opposite hand may be worn with the forearm end turned out to form a palm sided support for the fingers. This may be helpful as an interim measure.

What can a doctor do to help?

* Confirm that this actually is the problem.

* Prescribe stronger NSAID medication or cortisone type medication.

* Prescribe hand therapy and/or a custom prescription splint.

* Give a cortisone shot into the sore area. Usually, no more than two shots are given into one finger because more may lead to complications, such as tendon rupture.

* Perform surgery.



References:
1.http://www.eatonhand.com/hw/hw022.htm
2.http://www.medicinenet.com/trigger_finger/article.htm
3.http://orthoinfo.aaos.org/topic.cfm?topic=a00024
4.http://www.mayoclinic.com/health/trigger-finger/ds00155
5.http://www.merck.com/mmhe/sec05/ch071/ch071c.html#MMHE_05_071_02