Catching or popping of the finger when opening from a closed fist is referred to as “stenosing tenosynovitis” or commonly trigger finger or thumb. The tendons that bend the fingers are held close to the bone by bands referred to as “pulleys” similar to a line held on a fishing rod. During normal movement of the finger, tendons glide smoothly beneath these pulleys. If the tendon gets thicker or the pulley gets thickened from wear or scar, the tendon catches beneath the pulley and the finger clicks or pops as the tendon snags at the pulley. Most commonly triggering occurs at the level of the palm at the so called “A1” pulley.
WHAT CAUSES IT?
Trigger fingers usually occur with no known cause or in some cases after repetitive gripping. Some medical conditions such as diabetes or rheumatoid arthritis may also predispose to trigger finger.
WHAT ARE THE SYMPSTOMS?
Trigger finger may start with discomfort felt at the base of the finger or thumb, where the finger joins the palm. This area is often sensitive to pressure and a lump may be felt that moves with the tendon. Eventually the finger begins to catch and pop. The symptoms are often worse in the morning and catching can be quite painful.
As the condition progresses, you may lose the ability to fully straighten the finger.
Splinting the finger straight at night helps alleviate the discomfort by preventing triggering. Anti-inflammatory medications also may be helpful in early cases. Steroid injections are very effective in relieving symptoms and may even resolve the condition in more than half of the cases. Steroid injections should be used with caution in diabetic patients as they can elevate blood sugar for a few days.
If non-surgical treatment does not work or if the finger is “locked”, surgery is the best option. Under local anaesthesia a small incision is made in the palm and the tight pulley is released. Relief from the catching is instantaneous but stiffness resolves slowly and sometimes incompletely.