Trigger finger is a very common problem affecting people’s hands. It is one of the more common problems I see in the office. Trigger finger is a problem with the tendons that flex the joints in our fingers. These tendon are supposed to glide smoothly through tight tube within our fingers. Trigger finger occurs when the tendons that flex the fingers, instead of sliding through this very tight tube in the finger, become swollen and get stuck as the patient tries to extend the finger from a flexed position. Not only is it very awkward to have the finger get stuck in a flexed position, but it is often very painful. One of the most common questions I get in the office is “So, why did I get my trigger finger?”
Unfortunately, there is often not an answer to that question, but since the problem is a mismatch in the size between a tendon and this tube called the “flexor tendon sheath” sometimes we can guess at the underlying cause. The tendon has a very thin film around it which has a fairly impressive capacity to swell. So if a person fairly rapidly increases their activity with their hands and their fingers, this thin film can become inflamed and swollen which can cause the tendon to get stuck as the tendon tries to glide in that sheath. Sometimes the irritation begins with holding the finger in an awkward position for a prolonged amount of time or sometimes it applying quite a bit of force through that finger for a prolonged time.
There is also a fairly high correlation between arthritic finger joints and developing trigger finger. Thus, it is my suspicion that the increased force in flexing the stiff arthritic joints causes the tendon to swell or potentially even to hypertrophy or get thicker. Again, if the tendon is thicker than normal, then instead of sliding through that tight sheath, it will get “hung up.”
Again, along the same lines as swelling, sometimes trauma can cause trigger finger. Occasionally I will see someone who strikes their hand on a hard object and then subsequently develop trigger finger. I have even seen someone develop trigger finger from repetitively dunking a basketball, striking their hand on the goal.
Finally, it is well recognized that there is a high correlation between diabetes and developing trigger finger. It is not particularly clear why diabetes increases the risk of trigger finger, but there is likely something with having an increased blood sugar that causes some thickening of the tissues. In this case, sometimes the flexor tendon sheath will thicken which constricts the tube through which tendon needs to pass. It is also possible that the diabetes causes the flexor tendon to thicken.
Generally speaking, the first course of action in treating trigger finger is to administer a steroid injection into that flexor tendon sheath. The injectable steroid is the strongest anti-inflammatory medication that we have and typically it fairly rapidly decreases the inflammation and swelling, and reverses the triggering. Often, if the trigger finger is due to increased use or trauma, this will cure the problem permanently. Even when arthritis is the underlying cause of the triggering, the steroid injections have a 50-75% long-term cure rate. Unfortunately, patients with diabetes have a much higher risk of recurrence. Nonetheless, these steroid injections are very helpful in reducing or eliminating the pain associated with trigger finger – even in patients with diabetes. Thus, while the injection is typically not very pleasant, it is usually very helpful. Unfortunately, oral anti-inflammatory medications rarely have much of an effect in treating trigger finger.
If trigger finger recurs despite several steroid injections, then surgery can be considered. Typically if the steroid injections do not lead to long-term resolution of the triggering, then surgically opening the flexor tendon sheath leads to resolution of the triggering.
About the Author:
This article was written by Harrison G. Tuttle, M.D. Dr. Tuttle is a fellowship trained orthopaedic surgeon specializing in hand, wrist and elbow surgery, with a certificate of added qualification in hand surgery. His scope of practice includes the non-operative treatment and operative treatment of trauma, arthritic changes, congenital conditions, tendonapathy, peripheral nerve compression, as well as some skin and vascular conditions. In addition, Dr. Tuttle has served as the hand surgery consultant to the NHL’s Carolina Hurricanes since 2006.