|
Trigger finger (or thumb) is usually the result of a thickening in the tendon that forms a nodule, or knob. The pulley ligament around the tendon may thicken as well. The constant irritation from the tendon repeatedly sliding through the pulley causes the tendon to swell in this area and create a nodule.
When tendons that bend or flex the finger become enlarged, the affected individual is unable to extend his/her finger. The finger(s) affected may become painful to straighten. A crackling or popping sound is heard when the finger is moved. When the finger unlocks, it pops back suddenly. It mimics the action of releasing a trigger on a gun, which is how it got its name.
Triggering can occur as a result of rheumatoid arthritis, partial tendon lacerations, and repeated trauma from gripping power tools. Long hours grasping a steering wheel can also cause tendon triggering. People with diabetes may be at increased risk for trigger finger as well.
The reason for this connection isn't entirely clear. Most likely it's the result of multiple factors. Changes in connective tissue lead to thickening of the tendon sheath. This probably occurs as a result of damage to the blood vessels and nerves, accumulation of collagen in the skin and soft tissues, and attachment of sugars to proteins. These are all part of the diabetic process.
|
