Trigger finger, or locking fingers, is a condition characterised by a person's finger flexor tendon in the fingers or thumb catching, locking, or snapping into a bent position. When straightened, the finger flexor tendon emits a snapping noise, much like the sound of a trigger pull and release. In cases of severe trigger finger, the finger flexor tendon will lock in the bent position.
Trigger finger commonly occurs during later adulthood, in a person's dominant hand. This condition generally presents in the morning and often affects the ring finger or the thumb. Symptoms of trigger finger include a nodule or tenderness on the affected finger, stiffness of the finger in the morning, a clicking or popping sound when moving the fingers and fingers locked in a bent position then popping back into a straight position.
Typically, trigger fingers occur due to a gradually narrowing of the sheath surrounding the finger flexor tendon. Each protective sheath surrounding a tendon possesses a lining of tenosynovium, a substance designed to release lubricating liquid, which allows the tendons to move smoothly. In some cases, injury or conditions such as rheumatoid arthritis will inflame the tenosynovium and cause the narrowing of the protective sheath. This blocks the smooth movement of the tendons, causing a finger to catch or lock in a bent position before popping back into a straight position.
To properly diagnose trigger finger, a doctor will take a medical history and perform a physical examination. During the exam, the doctor will check for evidence of trigger finger by asking a patient to open and close her hands. This allows a doctor to test the smoothness of a person's tendon movement. In cases when a patient is in severe pain during the examination, a doctor will inject a patient with a local anesthetic to complete the examination.
There are several different types of treatment for trigger finger, depending on the severity and duration of the condition. For mild cases a doctor may suggest resting the hand for 4 to 6 weeks by avoiding any gripping action, massaging the affected fingers, soaking the affected hand in warm water several times a day, exercising the fingers to maintain mobility and wearing a splint on the affected finger for no more than six weeks. For severe cases, a doctor may suggest steroid injections or anti-inflammatory drugs to reduce the inflammation or percutaneous trigger finger release, a procedure which uses a needle to release the finger lock. If the condition does not respond to these treatment methods, a doctor will then suggest surgery.