Trigger finger

Overview

Trigger finger, also known as stenosing tenosynovitis is a condition in which a finger becomes locked in a bending position. When bending the fingers, there may be stiffness and a popping or snapping sound may be heard. The thumb and ring finger are the two fingers that are most commonly affected, but any finger may be affected by the condition.
Trigger finger occurs when the tendon controlling the affected finger cannot move freely within the sheath that covers it. This can happen if the tendon sheath swells in some area or develops a lump.
Women over 50 are most susceptible to developing trigger finger. Patients suffering from diabetes, hypothyroidism, or rheumatoid arthritis, may also be more susceptible to the condition. Treatment options may include resting, splinting, steroids injection, or surgery, depend on the severity of the condition.

Symptoms

Any finger, including the thumb, can develop trigger finger. It is possible for both hands and multiple fingers to be affected at once. The symptoms of trigger finger tend to be more pronounced in the morning.
Trigger finger signs and symptoms range from mild to severe are include:

• Snapping or popping sensation when moving the fingers.
• Pain or stiffness of fingers when bending.
• Tenderness or a lump at the base of the affected finger in the palm.
• Thumb or finger(s) being locked in a bent position (in severe cases), requiring gentle straightening with the assistance of the opposite hand.
• Inability to fully flex the fingers

Causes

Tendons are strong cords that connect bone to muscle and surrounded by a sheath. The tendons and muscles of the hand work together to flex and straighten the fingers and thumb. Trigger finger occurs when the tendon sheath of the affected finger becomes inflamed and swollen, making it more difficult for the tendon to move through the sheath.
The tendon may develop a lump or nodule, which makes it much more difficult for the tendon to easily slide through its sheath. In most cases, the cause of this irritation and swelling is unknown.

Risk factors

The following factors increase the risk of developing trigger finger:

• Age: People between the ages of 40 and 60 are commonly affected by trigger finger.
• Gender: Women are more likely to be affected by trigger finger than men.
• Occupation: Occupations and hobbies that require frequent use of the fingers and/or thumb such as grasping objects for an extended period of time, can increases the risk of developing trigger finger.
• Other conditions: Trigger finger is more likely to occur in patient with existing condition such as diabetes, osteoarthritis, gout, or rheumatoid arthritis.