Safe Injections for Trigger Finger in Patients with Diabetes
Trigger finger is a condition affecting the movement of the flexor tendons as they bend the fingers toward the palm of the hand. This movement is called flexion. Triggering is caused by a mismatch between the size of the tendon with its covering or lining (called the tendon sheath) and the pulley system the tendon and its sheath glide through.

The tendons that move the fingers are held in place on the bones by a series of ligaments called pulleys. These ligaments form an arch on the surface of the bone that creates a sort of tunnel for the tendon to run in along the bone. To keep the tendons moving smoothly under the ligaments, the tendons are wrapped in a slippery coating called tenosynovium.

The tenosynovium reduces the friction and allows the flexor tendons to glide through the tunnel formed by the pulleys as the hand is used to grasp objects. The constant irritation from the tendon repeatedly sliding through the pulley causes the tendon to swell in this area and create the nodule. This inflammation and swelling of the tendon sheath or the pulley leads to pinching of the tendon. The tendon fibers start to bunch up causing a nodule to form.

Symptoms of trigger finger include pain and a funny clicking sensation when the finger is bent. The clicking sensation occurs when the nodule moves through the tunnel formed by the pulley ligaments. With the finger straight, the nodule is at the far edge of the surrounding ligament.

When the finger is flexed, the nodule passes under the ligament and causes the clicking sensation. If the nodule becomes too large it may pass under the ligament, but it gets stuck at the near edge. The nodule cannot move back through the tunnel, and the finger is locked in the flexed trigger position. Pain occurs when the finger is bent and straightened. Tenderness occurs over the area of the nodule.

There are a variety of ways to treat this problem depending on how long it has been present and how severe the problem is. In this study, two specific injection treatments are compared for a particular population group. The two treatment approaches are nonsteroidal antiinflammatory (NSAID) injection and steroid injection. Two groups of patients were included: 50 patients with type 1 or type 2 diabetes mellitus and 50 patients without diabetes.

The reason the researchers focused on the use of injections for trigger finger in people with diabetes is because steroid injections can affect blood sugar control. The goal of this study was to see if a nonsteroidal antiinflammatory injection would have just as good of results as a steroid injection without affecting blood sugars.

And in fact, they did find that although the early results (after three weeks) were better with the steroid injections, the later results (after three months) were the same. These two types of injections have different ways in which they work but they do both provide the same pain relief and decrease in inflammation.

In summary, patients with diabetes who develop trigger fingers can be treated effectively with injections that don't affect glucose (blood sugar) levels. They get the same benefit as with steroid injections (that do affect blood sugars) -- just at a slightly slower rate.
Hussain Shakeel, MBBS, and T. Sara Ahmad, MBBS. Steroid Injection Versus NSAID Injection for Trigger Finger: A Comparative Study of Early Outcomes. In The Journal of Hand Surgery. July 2012. Vol. 37A. No. 7. Pp. 1319-1323.