Trigger Finger

Understanding Trigger Finger

Trigger finger, also known as stenosing tenosynovitis, is a condition that affects the tendons in your fingers or thumb, causing them to get stuck or “trigger” when trying to straighten out the finger. It happens when the tendon in the finger becomes irritated and swollen, which restricts smooth movement.

What happens with trigger finger?

The tendons in your fingers are responsible for bending and straightening your fingers. These tendons pass through a sheath, and when there is inflammation or thickening, the tendon can get caught in the sheath, preventing smooth movement. When the tendon catches, the finger may suddenly “snap” or “trigger” into a bent position and then straightens with a snap. It can also become stuck in a bent position.

Symptoms of Trigger Finger:

Pain: A sharp or aching pain at the base of the finger or thumb, especially when trying to straighten it.
Stiffness: The affected finger might feel stiff, especially in the morning or after periods of rest.
Popping or Clicking: When you try to straighten the finger, it might make a popping or clicking sound, or you might feel a sensation as if the finger “catches” or gets stuck.
Finger Locking: In more severe cases, the finger might become locked in a bent position and you may not be able to straighten it without assistance. When this happens, the finger may suddenly release and snap straight.
Swelling: Swelling or tenderness at the base of the affected finger or thumb, near the joint.
Bump: A small lump or bump might form at the base of the finger, where the tendon is irritated.
Limited Movement: The affected finger may have a reduced range of motion, making it harder to grip objects or perform tasks.

Treatment We Offer:

Ultrasound Guided Cortisone Injection

Ultrasound-guided cortisone (steroid) injections are an effective treatment option for trigger finger, particularly when other conservative methods (like rest, splinting, or oral medications) haven’t provided relief. This method uses ultrasound imaging to guide the injection directly to the affected area, ensuring accuracy and minimizing potential side effects.

How it Works:

Ultrasound Guidance: The procedure involves using an ultrasound machine to visualize the tendons and surrounding structures of the affected finger. The doctor can see exactly where the inflammation or thickening of the tendon is located.
Cortisone Injection: A corticosteroid (cortisone) is injected into the tendon sheath where the tendon is inflamed. Cortisone is a powerful anti-inflammatory medication that can help reduce swelling and alleviate pain.
Precision: By using ultrasound, the doctor can inject the medication precisely into the right spot, ensuring that the medication is delivered directly to the area where it’s needed. This increases the effectiveness of the injection and minimizes the chance of the injection affecting surrounding tissues.

Benefits of Ultrasound-Guided Cortisone Injection for Trigger Finger:

Accuracy: Ultrasound ensures that the needle is placed exactly where it’s needed, enhancing the effectiveness of the treatment.
Minimized Risk: With ultrasound guidance, the risk of injuring surrounding structures (like nerves or blood vessels) is minimized.
Reduced Pain: The steroid reduces inflammation in the tendon, which can provide significant relief from pain and stiffness.
Quick Procedure: The injection is typically done in a few minutes and usually performed in an outpatient setting.
Minimal Recovery Time: There’s usually no downtime after the procedure, and most people can return to normal activities quickly.

Your Care Pathway with us

To book an appointment you can call our normal reception line, 0142084487, email direct to info@altonpainclinic.co.uk or click the button given below.
Comprehensive Musculoskeletal examination and testing.
Same day Ultrasound Guided Injection for pain relief.
Discussion of your treatment plan; Treatment Plans can include i.e advanced treatments for ex. Cortisone Injections, Hyaluronic injections and various other options tailored for your specific needs.

Anatomy

The anatomy involved in trigger finger primarily includes the tendons, tendons sheaths, ligaments, and muscles in the fingers, along with the synovial sheath surrounding them. Here’s an overview of the anatomy:

1. Tendons:

Flexor Tendons: The primary tendons involved in trigger finger are the flexor tendons. These tendons run along the palm side of the fingers and thumb. They allow the fingers to bend (flex).
Each finger (except the thumb) has two flexor tendons (the flexor digitorum superficialis and flexor digitorum profundus), while the thumb has one flexor tendon (the flexor pollicis longus).
The tendons attach to muscles in the forearm and pass through the wrist into the hand.

2. Tendon Sheaths:

The tendons of the fingers are enclosed in protective, fibrous tendon sheaths. These sheaths are lined with a synovial membrane that secretes synovial fluid, allowing the tendons to glide smoothly as they bend and straighten the fingers.
The tendon sheaths are located at different parts of the finger, including the A1 pulley, which is located at the base of the finger near the metacarpophalangeal (MCP) joint.
The A1 pulley plays an important role in trigger finger, as it’s where the tendon can become irritated or inflamed, leading to the “catching” or “locking” of the finger.

3. Pulley System:

The tendons are held in place by a series of pulleys along their length. These pulleys prevent the tendons from bowstringing out of their normal position.
The most important pulley in trigger finger is the A1 pulley, which is located at the base of the finger. When the A1 pulley becomes thickened or inflamed, it restricts the movement of the tendon, causing it to catch and lock.

4. Ligaments and Joints:

The joints in the fingers are connected by ligaments that provide stability. These include the proximal interphalangeal (PIP) joint, the distal interphalangeal (DIP) joint, and the metacarpophalangeal (MCP) joint.
The MCP joint is the joint at the base of the finger, while the PIP and DIP are the middle and tip joints of the finger.

5. Synovial Fluid:

The synovial fluid within the tendon sheaths provides lubrication to allow smooth gliding of the tendons. In trigger finger, inflammation can lead to a buildup of thickened synovial fluid, contributing to pain and restricted movement.

6. Muscles:

Flexor muscles in the forearm control the flexion (bending) of the fingers. The primary muscles responsible for flexion are:
- Flexor digitorum superficialis: This muscle helps to bend the middle joint of the fingers.
- Flexor digitorum profundus: This muscle helps to bend the tip of the fingers.
- Flexor pollicis longus: This muscle helps to bend the thumb.
These muscles work in conjunction with the tendons and tendons sheaths to allow the fingers to move in a coordinated fashion.

Summary of Trigger Finger Mechanism:

Trigger finger occurs when the tendon becomes inflamed or irritated as it passes through the A1 pulley at the base of the finger. When this happens, the tendon thickens, and the tendon sheath becomes narrowed, preventing smooth movement.
The thickened tendon can get “stuck” as it moves through the pulley, resulting in the finger “locking” or “catching.”
When the tendon eventually breaks free, it may snap back into position, often with a popping or clicking sensation.

Understanding the anatomy of the finger and the role of the tendon sheath system is key to understanding how trigger finger develops and why treatments like cortisone injections or surgery can help restore normal function.

What is Trigger Finger?

Trigger finger (also known as stenosing tenosynovitis) is a condition where one of your fingers or your thumb gets stuck in a bent position and then suddenly pops straight, or it may stay locked in a bent position. It occurs due to inflammation or thickening of the tendons in the affected finger, which causes them to catch or “trigger” when moving.

How Trigger Finger Develops:

In your fingers and thumb, there are tendons that help bend and straighten them. These tendons are housed in a tendon sheath that allows smooth movement. When you have trigger finger, the tendon and its sheath become inflamed or swollen. This causes the tendon to catch on a fibrous structure called the A1 pulley at the base of the finger (a part of the tendon sheath). The result is that the tendon is unable to glide freely, and the finger gets “stuck” in a bent position.

Key Symptoms:

Pain at the base of the finger or thumb, especially when trying to straighten it.
Stiffness in the affected finger, particularly in the morning.
A popping or clicking sound when the finger is straightened.
Swelling or a small bump at the base of the finger.
Locking of the finger in a bent position that can be difficult to straighten.

Causes:

Trigger finger can develop for a variety of reasons:

Repetitive motion: Overuse or repetitive gripping motions, such as holding tools or using devices, can cause irritation.
Injury: A finger injury can contribute to the development of trigger finger.
Underlying health conditions: Conditions such as rheumatoid arthritis, diabetes, or gout can increase the likelihood of developing trigger finger.
Age: People over the age of 40 are more prone to this condition.
Gender: Women are more likely to develop trigger finger than men.

Treatment Options:

Treatment for trigger finger often starts conservatively and may include:

Rest: Avoiding repetitive activities that stress the affected finger.
Splinting: Wearing a splint to keep the finger in a neutral position to reduce strain.
Anti-inflammatory medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and swelling.
Corticosteroid injections: These are used to reduce inflammation and are often guided by ultrasound for accuracy.
Physical therapy: Exercises to improve the tendon’s movement and flexibility.
Surgery: In severe cases, when other treatments don’t work, a surgical procedure can release the tendon from the sheath, allowing it to glide freely.

Trigger finger can range from mild to severe, and while many cases can be treated with non-invasive methods, some may require more advanced interventions to restore normal finger movement.

Diagnosis

During your evaluation for trigger finger, your clinician will discuss your medical history, ask about your symptoms, and perform a detailed examination of your hand and fingers. This may involve several physical tests, including:
1. Palpation of the Affected Area:
Your clinician will press on the base of your finger, where the tendon sheath is located, to check for tenderness or swelling. The area around the A1 pulley will be carefully examined to feel for any thickening or bumps.
2. Flexion and Extension Test:
Your clinician may ask you to bend and straighten your finger to check for any “catching,” “snapping,” or locking. This test helps assess the movement of the affected tendon through the tendon sheath.
3. Finger Resisted Flexion Test:
Your clinician might apply resistance as you attempt to flex or bend your finger. This helps evaluate the strength and smoothness of the tendon movement.
4. Checking for Triggering or Locking:
Your clinician will observe whether your finger gets stuck in a bent position or has difficulty straightening. They will assess whether it releases suddenly with a snap.
5. Range of Motion (ROM) Test:
The clinician will evaluate the flexibility and range of motion of your affected finger to determine if there is any stiffness or restricted movement.
6. Tendon Gliding Test:
Your clinician may guide you through specific exercises to test how well the tendon glides through its sheath, which can help determine if the tendon is being constricted or “catching.”
7. Ultrasound Imaging:
An ultrasound may be used to visualize the tendon and surrounding tissue. This imaging can help identify any thickening of the tendon sheath or inflammation, which is common in trigger finger.
8. Assessing Swelling and Bumps:
Your clinician will check for visible swelling or a bump near the base of the finger. A small nodule or bump is often present when there’s inflammation or irritation of the tendon.
This thorough examination helps your clinician confirm a diagnosis of trigger finger and determine the most appropriate treatment plan, which could range from rest and splinting to injections or surgery depending on the severity of your condition.