The trigger finger/trigger thumb is classified according to severity and affected area:

1. Grade 1: Pain and slight stiffness without visible "snapping."
2. Grade 2: Noticeable "snapping" during movements, without the finger getting stuck.
3. Grade 3: Blocking of the finger or thumb, which can be actively overcome.
4. Grade 4: Permanent fixation of the finger or thumb, which cannot be resolved either actively or passively.
5. Affected areas:
   • Trigger finger: Ring, middle, or index finger.
   • Trigger thumb: Often affected due to intensive use.

The main causes are mechanical, inflammatory, or systemic factors:

- Mechanical stress:

- Repetitive movements, as seen in manual work, sports, or playing music.

- Overuse of the fingers or thumb due to repetitive tasks.

- Inflammatory processes:

- Thickening of the tendon sheath due to microtraumas or local inflammations.

- Systemic diseases:

- Rheumatoid arthritis, diabetes mellitus, or gout, which can affect the tendon gliding tissue.

- Anatomical factors:

- Congenital narrowings or scarring of the tendon sheaths.

The symptoms vary depending on the severity of the condition, but typically include:

• Pain: Localized pain at the base of the finger or thumb, especially with pressure or movement.
• Snapping: A jerky bending or straightening, often accompanied by an audible or palpable resistance.
• Locking: Finger or thumb remains fixed in a bent or straight position.
• Stiffness: Noticeable especially in the morning.
• Swelling: Thickening in the area of the tendon sheath.
• Tenderness: Pain on pressure at the affected site.

The diagnosis is based on medical history, clinical examination, and, if necessary, imaging techniques:

• Medical history:
  • Inquiring about the duration and intensity of symptoms as well as possible stress factors.
• Physical examination:
  • Palpation of the affected tendon sheath to identify thickenings or pain points.
  • Observation of the "snapping" during finger movement.
• Imaging:
  • Ultrasound: Visualization of thickenings or narrowings in the tendon sheath.
  • MRI: Only necessary in rare cases, if there is suspicion of accompanying soft tissue damage.

Conservative Therapy

In early stages, non-operative measures can alleviate symptoms:

• Immobilization: Resting the affected finger or thumb using splints or bandages.
• Medication Therapy:
  • NSAIDs: To reduce pain and inflammation.
  • Corticosteroid injections into the tendon sheath for quick relief.
• Physiotherapy:
  • Stretching and mobilization exercises to improve mobility.
  • Manual therapy to release adhesions.
• Local Applications:
  • Cold therapy for pain relief in acute conditions.
  • Heat applications for chronic symptoms.

Surgical Therapy

In advanced cases or persistent complaints, surgery is required:

• Annular Ligament Release: Surgical widening of the tendon sheath to restore free gliding ability.
• Minimally Invasive Techniques: Gentle procedures with quick rehabilitation.

The following measures are suitable for prevention and support of recovery:

1. Avoidance of overexertion: Reduction of repetitive movements, especially with intensive use of fingers or thumbs.
2. Ergonomic work design: Adjustment of tools or work environments.
3. Regular breaks: Relieving the hands during repetitive activities.
4. Strengthening and stretching: Targeted training of hand and finger muscles.
5. Early detection: A doctor should be consulted promptly at the first signs of pain or stiffness.