The human hand is made up of bones, muscles, ligaments, tendons, and joints. When it works correctly, the hand is capable of performing many functions, such as gripping, lifting, aligning, opening, closing, and placing objects.
Each hand normally has four fingers and one thumb. The fingers consist of three bones each, while the thumb has two. Tendons connect the muscles to the finger bones and thumb. Each tendon is surrounded by a sheath, a membrane that permits the tendon to move easily within the finger joint. The tendon sheath is attached to the finger bone and stabilizes the tendon against the bone so that it glides smoothly.
The complexity of the hand is what gives it its wide range of functionality, but it also means there are many ways problems can arise.
When the tendon sheath is inflamed, it narrows the space between the sheath and the tendon, restricting movement. The finger may become stuck in a bent position, or bend and straighten with a snapping or clicking sound similar to that of a trigger being pulled and released. It may also be stiff, tender, or swollen, particularly in the morning. In some cases, a bump or nodule may develop at the base of the affected finger. This condition is called trigger finger, also known as stenosing tenosynovitis.
Any digit may develop trigger finger, although it is most common in the thumb and ring finger. More than one finger can be affected at once, and both hands can suffer from trigger finger at the same time.
Women and individuals with hormone imbalance issues, such as diabetes or a hyperthyroidism, or any inflammatory disease, such as rheumatoid arthritis or Dupuytren’s contracture, are at the highest risk of developing trigger finger. It is also common among people with jobs or hobbies that involve repetitive movement or constant gripping of an object for an extended period of time. Patients who undergo surgery for carpal tunnel syndrome may also develop trigger finger, usually within six months after the surgery.
Trigger thumb also results from an inflamed or irritated tendon sheath. It is characterized by pain or tenderness at the base of the thumb, a clicking or snapping sound when the thumb is moved or flexed, stiffness, and/or the inability to easily bend or unbend the thumb. Trigger finger and trigger thumb may occur at that same time, on one hand, or on both hands.
When trigger finger or trigger thumb is suspected, it is important to consult with a physician. The physician will examine the hand, review the medical history, and may request that the affected hand undergo an X-ray. Imaging can help rule out out sprains, fractures, bone displacement, and ligament or muscle damage. It also allows the physician to target the tendon sheaths causing trigger finger or trigger thumb.
Treatment strategies for trigger finger and trigger thumb depend on the severity of the condition. For example, sometimes the finger may lock only sporadically. Other times, it may appear to be bent permanently and cannot be easily moved. Differently manifesting cases require different treatments.
Conservative treatments include resting the hand, avoiding repetitive motion, wearing a splint at night, and taking over-the-counter anti-inflammatory medications. When those strategies fail to provide relief, other treatments to reduce the pain and inflammation of trigger finger or trigger thumb include steroid injections into the tendon sheath or the surrounding area.
When conservative treatments fail to provide relief, surgery will be recommended.
Typically, surgery is used to increase the space within the tendon sheath so the tendon can move smoothly within the finger or thumb.
Surgery is performed in a hospital on an outpatient basis. The surgeon numbs the hand with a local anesthetic, makes a small cut near the affected finger or hand, and then cuts into the tendon sheath. If this allows the thumb or finger to move smoothly, stitches will be used to seal the incision. The patient will be permitted to return home the same day.
Most patients are able to move the affected finger/thumb immediately for light tasks. Generally, the patient will wear a bandage at the incision site until the first post-operative visit. The bandage must be kept dry. If the finger/thumb and hand are tender, ice packs should alleviate the pain. Patients may also be asked to keep the hand propped up above the heart to minimize swelling. There may also be restrictions on returning to work, driving, and participation in sports.
“How do hands work?” NCBI Resources, https://www.ncbi.nlm.nih.gov/books/NBK279362/
“Trigger Finger,” OrthoInfo, https://orthoinfo.aaos.org/en/diseases--conditions/trigger-finger
“What to Expect from Trigger Finger Surgery,” Healthline, https://www.healthline.com/health/trigger-finger-surgery