Trigger finger is a common problem that causes pain and snapping of the tendons in the fingers. The problem that occurs in a patient who has trigger finger is due to the tendons of the fingers, and the sheath in which these tendons live.
What are tendons?
The tendons in your fingers are like ropes that attach to the ends of your fingers. When your forearm muscle contracts, the tendons pull the fingers into a fist. The tendons run part of their course through a sheath called the flexor tendon sheath. In patients who have a trigger finger, this mechanism of movement is not smooth.
What causes trigger finger to happen?
The cause of trigger finger is unclear, and can seemingly appear from nowhere. It can occur in one or more fingers, and can occur at different times in different locations. Trigger finger results from a discrepancy between the size of the tendon and the entrance to the tendon sheath. This discrepancy can be the result of localized inflammation or a nodular swelling on the tendon itself.
When the size discrepancy between the tendon and the tendon sheath reaches a critical point, the tendon will experience resistance from the tendon sheath. At first, this is experienced as a snapping of the trigger finger when relaxing a fist. If the condition worsens, the trigger finger may need active force from other fingers to straighten, or may not straighten at all.
Why is it called a trigger finger?
The name trigger finger is from the symptom of triggering or snapping. This occurs when relaxing a fist, the affected trigger finger remains flexed. When enough force has been gathered, the trigger finger will suddenly extend, like pulling a trigger.
The most common treatment of trigger finger is with injection of steroids (cortisone injection) into the flexor tendon sheath. The cortisone injection should decrease the swelling within the tendon, and restore the normal mechanics of the flexor tendon mechanism.
Usually a single cortisone injection will resolve, at least temporarily, the trigger finger. The chance of the cortisone injection providing a lasting solution for a trigger finger is about 50%.
Is surgery necessary to treat trigger finger?
If the problem does not resolve, a surgery to release the tendon may be necessary. This procedure is a same day surgery that can be done under local anesthetic or regional nerve block. A small (less than 2 cm) incision is made in the skin, and the tight portion of the flexor tendon sheath is released.
Following the procedure, a sterile bandage is applied to the site of surgery. This bandage is removed after a few days, and full use of the finger may then begin. Activity of the finger is encouraged as this will help prevent new adhesions (scar) from forming where the surgery was performed. Full recovery is expected for surgery.
What are the possible complications of a trigger finger release?
Trigger finger surgery is very safe, but there are possible complications. The most common problem is that the trigger finger can come back if the tendon sheath is not adequately released. Other possible problems include infection, stiffness of the finger, and damage to the nerves of the finger. The likelihood of these problems is very small, and trigger finger surgery has a very high success rate.
Users browsing this forum: No registered users and 45 guests