The syndrome is classified according to cause and severity:

- According to cause:

- Mechanical: Repeated pressure or trauma to the elbow.

- Anatomical: Narrow bone canal or structural changes.

- Systemic: Accompanying conditions in diseases such as diabetes or rheumatoid arthritis.

- According to severity:

- Mild: Temporary discomfort without permanent neurological deficits.

- Moderate: Frequent symptoms with initial motor limitations.

- Severe: Persistent pain, muscle weakness, and atrophy of the hand muscles.

The causes of the syndrome can be divided into mechanical, anatomical, and systemic factors:

• Mechanical causes:
  • Repeated resting of the elbow on hard surfaces ("cell phone elbow").
  • Hyperextension or injuries, e.g., from sports or accidents.
• Anatomical causes:
  • Narrowing of the ulnar nerve groove due to bone growths or cysts.
  • Subluxation of the ulnar nerve, where the nerve slips out of its guide.
• Systemic causes:
  • Diabetes mellitus, which makes nerves more susceptible to compression.
  • Rheumatic diseases or inflammatory processes.

The symptoms vary depending on the severity of the nerve compression and typically include:

- **Paresthesia:** Tingling or numbness in the last two fingers (ring finger and little finger).

- **Pain:** Tenderness at the elbow with possible radiations into the forearm or hand.

- **Weakness:** Reduced strength in the hand, especially when gripping or spreading the fingers.

- **Atrophy:** Shrinking of the small hand muscles in advanced disease.

- **Worsening with strain:** Intensification of symptoms with prolonged bending of the elbow, e.g., when talking on the phone or sleeping.

The diagnosis is based on medical history, clinical examinations, and electrophysiological tests:

• Medical History:
  • Collection of symptoms, stress patterns, and possible injuries.
• Physical Examination:
  • Palpation of the elbow for tenderness and subluxation of the nerve.
  • Provocation tests such as the Tinel test or the elbow flexion test.
• Electrophysiological Examinations:
  • Nerve Conduction Velocity (NCV): Detection of slowdowns in the area of the ulnar sulcus.
  • EMG (Electromyography): Assessment of the function of the affected muscles.
• Imaging:
  • Ultrasound: Visualization of the nerve and possible anatomical constrictions.
  • MRI: For the assessment of soft tissues and structural changes.

Conservative Therapy

In mild to moderate cases, conservative treatment is initially applied:

• Relief of the nerve:
  • Avoiding pressure on the elbow, e.g., through padding or avoiding certain movements.
• Orthoses: Use of elbow splints for immobilization, especially at night.
• Physiotherapy:
  • Exercises to improve mobility and relieve the nerve.
  • Strengthening the muscles to stabilize the elbow.
• Medication therapy:
  • NSAIDs: For pain relief and anti-inflammatory effects.
  • Local injections of corticosteroids for persistent symptoms.

Surgical Therapy

In severe cases or lack of improvement after conservative therapy, surgery is recommended:

• Decompression: Removal of tissue or bone growths that constrict the nerve.
• Nerve transposition: Relocation of the nerve from the sulcus nervi ulnaris to a less stressed position.
• Post-treatment: Physiotherapy to restore mobility and function.

To prevent ulnar nerve sulcus syndrome and reduce the risk of recurrence, the following measures are suitable:

1. Ergonomic posture: Avoid prolonged leaning on the elbow.
2. Movement breaks: Regularly interrupt unilateral strains.
3. Protection of the elbow: Use pads or protectors during strenuous activities.
4. Correct movement behavior: Avoid excessive elbow bending for extended periods.
5. Early detection: Seek medical advice early at the first symptoms to prevent worsening.