Trigger Thumb is a condition where the flexor tendon to the thumb becomes inflamed and swollen because it is being forced to make a near 90% turn as it exits the pulley at the base of the thumb.
All fingers have a pulley where the tendon leaves its sheath in the palm and enters into the finger or thumb. Hence all fingers are susceptible to this problem.
A swollen part of the tendon is then forced into and out of the pulley as the patient continues to use his hand. This results in obstruction of gliding and the swollen part of the tendon gets caught on one side or the other of the pulley. When the tendon is forced through the pulley, it acts like a trigger, with a painful popping sensation with flexion, then extension, much like pulling a trigger.
Even though we know what the process is, all of our technology has failed to explain why it happens in some people, and not in others. Most certainly, extensive repetitive motion, especially if the patient is not used to performing this motion, can cause inflammation. However some people will develop this when there has been no change in their usual daily routine.
Treatment involves one of two goals:
- Make the swollen tendon more narrow by relieving the swelling and inflammation. This is done by injecting the tendon sheath with a steroid solution.
- Making the passageway through the pulley wider allows the swollen tendon to glide with less friction, allowing the inflammation and swelling to resolve.
At the Thumb Specialty Center, our success rate of completely curing the problem with injection meets with the national average of approximately 65%.
In those patients who have a return of pain or triggering, a second injection has about the same likelihood of curing the problem. Surgery is necessary in only 12% of our patients.