Trigger Finger: Causes, Symptoms, and Treatments

Why Does My Finger Get Stuck When I Move It?

Your finger getting stuck, catching, or locking during movement is most commonly a symptom of a condition known as Trigger Finger, or Stenosing Tenosynovitis, which involves inflammation and narrowing within the tendon sheath system of the affected digit.

Understanding Finger Movement: The Tendon-Pulley System

To comprehend why a finger might get stuck, it's essential to first understand the intricate mechanics that allow for smooth, effortless finger movement. Our fingers move due to the contraction of muscles in the forearm, which pull on long, cord-like structures called tendons. These tendons extend from the forearm, through the wrist, and attach to the bones of the fingers.

As these tendons cross the palm and fingers, they are held close to the bones by a series of fibrous tunnels known as pulleys (specifically, annular pulleys). Think of these pulleys like the eyelets on a fishing rod, keeping the line (tendon) close to the rod (bone) to ensure efficient pulling. Each tendon is also encased in a protective synovial sheath, a lubricated tunnel that allows the tendon to glide smoothly and friction-free as it moves.

The Primary Culprit: Trigger Finger (Stenosing Tenosynovitis)

The most common reason for a finger to "get stuck" is a condition called Trigger Finger, medically known as Stenosing Tenosynovitis. This condition directly affects the smooth gliding mechanism of the finger tendons.

• What is Trigger Finger? It's an inflammatory condition where the flexor tendon (the tendon responsible for bending your finger) or its surrounding synovial sheath becomes inflamed and swollen. This swelling can lead to the formation of a small nodule or thickening on the tendon itself, or a narrowing of the pulley through which the tendon must pass.

• How It Happens: The Pathophysiology When the tendon and/or its sheath become inflamed, the normally smooth glide of the tendon through its pulley system is disrupted. If a nodule forms on the tendon, or the pulley itself becomes too narrow, the tendon essentially gets "snagged" as it tries to pass through the constricted tunnel. This is particularly noticeable when extending the finger from a bent position.

• Key Symptoms

  • Catching or Locking: The hallmark symptom. You might feel a distinct "pop" or "click" as the finger flexes or extends, or it might lock in a bent position, requiring manual straightening with the other hand.
  • Pain: Often felt at the base of the affected finger or thumb, especially when trying to move it or when applying pressure.
  • Stiffness: Especially noticeable in the morning.
  • Tenderness: A palpable lump or tenderness may be present at the base of the affected finger, in the palm.
  • Limited Movement: In severe cases, the finger may become permanently bent.

• Commonly Affected Digits While any finger can be affected, the thumb, middle finger, and ring finger are most commonly involved. It can affect more than one finger at a time.

• Risk Factors Several factors can increase the likelihood of developing trigger finger:

  • Repetitive Gripping: Activities that involve repetitive or forceful gripping, such as using power tools, gardening, or certain sports.
  • Certain Medical Conditions: Individuals with diabetes, rheumatoid arthritis, gout, or hypothyroidism have a higher incidence of trigger finger.
  • Gender: It is more common in women than men.
  • Age: Most common in people between 40 and 60 years old.

Why Does It "Get Stuck"? The Mechanics of Locking

The "getting stuck" sensation is a direct result of the mismatch between the size of the inflamed tendon/nodule and the constricted pulley. When you attempt to straighten your finger from a bent position, the swollen part of the tendon (or the nodule) struggles to pass through the narrowed opening of the pulley. It gets momentarily caught, causing the finger to resist extension. With enough force (either from the muscle contracting or manual assistance), the nodule eventually "pops" through the pulley, often with an audible click or a sudden release of the finger. This sudden release can sometimes be painful. Conversely, when bending the finger, the nodule might get caught on the way in, making it difficult to fully straighten afterwards.

When to Seek Professional Medical Advice

While trigger finger can sometimes resolve on its own with rest and activity modification, it's crucial to consult a healthcare professional, such as a general practitioner, orthopedist, or hand specialist, if you experience:

• Persistent pain or discomfort.
• Frequent catching or locking that interferes with daily activities.
• Inability to fully straighten or bend your finger.
• Signs of infection (redness, warmth, swelling, fever).
• Your symptoms are worsening or not improving with self-care.

Early diagnosis and intervention can often prevent the condition from progressing and becoming more severe.

Diagnosis and Treatment Options

A healthcare professional will typically diagnose trigger finger based on a physical examination of your hand and fingers, observing the locking or catching sensation. Imaging tests are rarely needed.

• Conservative Management Initial treatment usually focuses on non-surgical approaches:

  • Rest and Activity Modification: Avoiding activities that aggravate the condition, especially repetitive gripping.
  • Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Over-the-counter medications like ibuprofen or naproxen can help reduce pain and inflammation.
  • Splinting: Wearing a splint, particularly at night, can help keep the finger in an extended position, allowing the tendon to rest and reduce inflammation.
  • Corticosteroid Injections: A common and often highly effective treatment involves injecting a steroid medication directly into the tendon sheath at the base of the affected finger. This helps reduce inflammation and swelling, allowing the tendon to glide more freely. Multiple injections might be needed, but there's a limit to how many can be safely given.

• Surgical Intervention If conservative treatments are unsuccessful, or if the finger remains locked, surgery may be recommended. This procedure, typically performed under local anesthesia, is called a percutaneous release or open trigger finger release. The goal is to cut open the constricted pulley (usually the A1 pulley) to create more space for the tendon to glide through, immediately relieving the catching and locking. Recovery is generally quick, with most people regaining full function within a few weeks.

Prevention and Self-Care Strategies

While not all cases of trigger finger can be prevented, especially for those with underlying medical conditions, certain strategies can help reduce your risk and manage symptoms:

• Ergonomic Adjustments: If repetitive tasks are a trigger, adjust your grip, tools, or workstation to reduce strain on your hands and fingers.
• Regular Breaks: Take frequent breaks from repetitive hand activities to stretch and rest your hands.
• Gentle Stretching and Exercises: Maintain flexibility in your fingers and hands with gentle stretches. Consult a physical or occupational therapist for specific exercises.
• Warm-Up: Before engaging in activities that require repetitive hand movements, perform a gentle warm-up.
• Ice or Heat: Applying ice packs can help reduce inflammation, while heat can soothe stiffness.
• Listen to Your Body: Pay attention to early signs of discomfort and modify activities before symptoms become severe.

Understanding the mechanics behind why your finger gets stuck empowers you to take appropriate action, whether it's through self-care or seeking professional medical guidance.