Trigger thumb, also known as stenosing tenosynovitis, is a condition that involves the tendons and tendon sheaths in the thumb. Trigger thumb occurs when the patient first bends the finger, and then tries to straighten the finger and the finger locks or catches or suddenly pops out straight, as when pulling a trigger and it suddenly pops back. This condition occurs because a nodule may form in the tendon, which can be caught as it passes through the tendon sheath, and results in symptoms of trigger thumb. In this case, the patient should understand the causes of trigger thumb to avoid this condition's occurrence.
Strain Injury
According to the American Academy of Orthopaedic Surgeons, a trigger finger may occur after an activity that causes a strain injury to the hand. A strain injury may occur with hyperextension, or excessive stretching of the thumb, which can damage the flexor tendon of the thumb. In response to injury, the flexor tendon may form a nodule, which can eventually grow and get caught as it passes through the tendon sheath in the thumb. This will result in a patient having trigger thumb. In this case, a patient should provide a detailed history of possible strain injury to the thumb in this position, so that the proper diagnosis can be reached so that treatment can be started.
Overuse
A patient who overuses the thumb may develop trigger thumb, states MayoClinic.com. This occurs because overuse can cause inflammation in the tendon sheath, which may cause the narrowing of the passageway in which the tendon passes. This may make extending the thumb after flexing it difficult because the tendon is rubbing along the tendon. Over time, the tendon may continue to thicken, which will worsen the symptoms. A patient who is having symptoms of trigger thumb and participates in a hobby or activity that involves extensive thumb use should contact a physician. With proper diagnosis, the treatment of trigger thumb can be started. Most cases of trigger thumb are treated conservatively, but more severe cases may require surgical relief.
Inflammatory Conditions
Inflammatory conditions may cause trigger thumb in some patients. This occurs because inflammatory conditions, such as rheumatoid arthritis or diabetes, may adversely affect the tendon in the thumb or in other fingers. These conditions can cause the tendon in the thumb to become inflamed, which will make it difficult for it to pass through the tendon sheath easily. This results is a catching of the thumb in a bent position. In this case, a patient should continue following the recommendations for whatever inflammatory condition he may have. Strict adherence to a physician's advice will prevent worsening of trigger thumb or development of other trigger fingers. Once the inflammatory condition is under control, surgery may be necessary.
