Trigger finger is an often painful condition characterized by a popping or snapping sensation in the finger or thumb joints.
One of the most common causes is a mismatch between the size of the tendon that moves the finger into a flexed position and the underlying ligament structure that holds that tendon in place.
If the protective covering surrounding the tendon (the tendon sheath) becomes inflamed and thickens, the tendon can't glide smoothly as you bend and extend your finger. When this happens, the finger or thumb may catch in a bent position before straightening with a pop, like a trigger being pulled and released. With each catch, the tendon itself becomes irritated and inflamed, worsening the problem.
The condition is more common in people older than 40 and can affect any finger, including the thumb. Although you're at greater risk if you have diabetes or rheumatoid arthritis, trigger finger typically is not associated with any particular medical condition. If your work or hobby involves repeatedly or strenuously gripping an object for prolonged periods, you may be more prone to trigger finger.
Trigger finger develops entirely outside the joint and has no direct association with osteoarthritis, although symptoms may include finger stiffness and tenderness at the base of the affected finger. Generally, the problem starts with mild popping as you flex and extend the finger. Sometimes the problem never progresses further. Other times, it becomes so severe that once your finger is bent into the palm area, it literally locks in place and can only be straightened when opened by the opposite hand. As the finger is opened, the enlarged tendon slips through the thickened ligament, like a knot on a rope being pulled through a pulley that is too tight. Popping and pain are felt as the tendon moves past the tight area.
Treatment varies depending on the severity of the condition. You may notice improvement by decreasing repeated gripping actions in the affected hand and massaging the nodular, tender part of the palm. Your doctor may apply a temporary splint to rest the finger in an extended position.
Nonsteroidal anti-inflammatory medications, such as ibuprofen or naproxen, may relieve the inflammation, swelling and pain.
If these more conservative measures are not successful, cortisone injections, sometimes combined with splinting, successfully treat 60 to 70 percent of nondiabetic patients with trigger finger. The steroid injections may not be as effective in those with diabetes.
If the finger locking doesn't respond to other treatments, an outpatient procedure can be performed under local anesthesia to release the tendon. The surgery has very few complications and recurrence of the problem in the same finger is rare. However, patients successfully treated for one trigger finger may develop another trigger finger, on the same or opposite hand, a few months or even several years following the surgery.
The good news is that trigger finger is highly treatable, and developing the condition does not indicate that you have arthritis.