H15 - Nighttime Trigger Finger Orthosis

Trigger Finger (also known as: Trigger Thumb), medically referred to as "Flexor Tendon Sheath Inflammation"

Symptoms include the finger getting stuck in a bent position. This occurs due to the deep flexor tendon forming a nodule at the base of the finger, causing the finger to catch on the tendon pulley when trying to straighten it, preventing full extension. There may also be resistance when straightening, resembling a trigger mechanism.

In the early stages, symptoms are relatively mild and difficult to detect. Common signs include:
{ Trigger finger most commonly occurs in the thumb, followed by the ring finger, middle finger, little finger, and index finger. }

• The finger makes a popping sound when bending or straightening the thumb or finger.
• The base of the thumb or finger may feel painful and thickened (nodule).
• In some cases, the finger can get stuck and cannot straighten.
• The finger becomes stiff, especially in the morning, making movement difficult.

Trigger Finger can be classified into four stages:

Why is there a sound?

Tendons are soft tissues in the body that connect muscles to bones, while the tendon sheath is a hollow tubular structure, like a tunnel, through which the tendon moves.

Under normal circumstances, tendons can glide smoothly within the sheath when the fingers bend and straighten. However, excessive pressure on the fingers can lead to tendon inflammation, such as when lifting heavy objects or gripping tools tightly.

As we know, when tissues become inflamed, they swell. If ignored, nodules may form, leading to the "locking" phenomenon, which is the reason for the so-called "trigger sound."

Causes:

Overuse of the fingers (repetitive motions or frequent, high-intensity activities) can lead to inflammation and swelling due to excessive pressure on the joints. Occupations like electricians, crafters, bakers, and homemakers are common groups affected by trigger finger.

When fingers are overused, excessive friction occurs between the pulley and flexor tendon, leading to inflammation, swelling, and narrowing of the pulley and sheath, accompanied by localized thickening of the flexor tendon, preventing free movement of the tendon within the sheath.

Frequent finger movements, prolonged activity, or excessive force can cause the tendon at the joint to continuously rub against the ligaments, resulting in inflammation and swelling, known as flexor tendonitis. If not rested or treated, nodules may gradually form.

Treatment Options:

1. Conservative Treatment: Using the H15b orthosis for rest will naturally reduce inflammation and swelling, allowing for unlocking and natural recovery.
2. Surgery (suitable for Stage 4): Incision of the annular ligament, easy dislocation, longer recovery time, and risk of infection.