What is the treatment for ulnar nerve subluxation?

Treatment of Ulnar Nerve Subluxation

Surgical treatment is recommended for patients with habitual ulnar nerve subluxation/dislocation at the elbow, as it is more effective than conservative management for this specific condition. 1

Diagnosis and Assessment

• Dynamic ultrasound is the preferred diagnostic tool for ulnar nerve subluxation, as it can clearly demonstrate nerve dislocation during elbow movement 1, 2
• MRI can be used as a reference standard for imaging, with T2-weighted MR neurography showing high signal intensity and nerve enlargement 1
• Clinical presentation typically includes:
  • Pain radiating from the elbow to the forearm
  • Tenderness at the posteromedial aspect of the elbow
  • Pain aggravation with elbow flexion
  • Sometimes a palpable band in the medial elbow region 3, 2

Conservative Management

Conservative treatment should be attempted first in mild cases or acute traumatic subluxation:

• Patient education on avoiding prolonged elbow flexion and direct pressure on the nerve 1
• Elbow immobilization with a broad arm sling for approximately 3 weeks in acute traumatic cases 3
• Activity modification to reduce strain on the elbow 1
• Encouraging optimal postural alignment at rest and during activities 1

For associated pain symptoms:

• First-line medications may include:
  • Calcium channel α2-δ ligands (gabapentin 900-3600 mg/day or pregabalin 300-600 mg/day)
  • Tricyclic antidepressants (nortriptyline or desipramine, 10-75 mg/day)
  • SNRIs (duloxetine 60-120 mg/day or venlafaxine 150-225 mg/day) 1
• Topical agents such as lidocaine patches or creams may provide relief for neuropathic pain 1

Adjunctive Therapies

For patients with mild symptoms or those awaiting surgery:

• Ultrasound therapy (frequency of 1 MHz, intensity of 1.5 W/cm², continuous mode, five times a week for 2 weeks) has shown significant improvements in clinical and electrophysiological parameters 4
• Low-level laser therapy (0.8 J/cm² with 905 nm wavelength, five times a week for 2 weeks) may also provide short-term effectiveness 4

Surgical Management

Surgery is indicated for:

• Habitual ulnar nerve subluxation/dislocation at the elbow 1
• Severe symptoms unresponsive to conservative measures
• Progressive neurological deficits
• Failed conservative treatment after approximately 3 months
• Significant functional limitation 1

Surgical Options:

1. Simple in situ decompression - Treatment of choice for primary cubital tunnel syndrome, extending at least 5-6 cm distal to the medial epicondyle 5

2. Anterior transposition - Preferred for symptomatic ulnar nerve subluxation:

   • Subcutaneous anterior transposition - When the luxation is painful or when the ulnar nerve "snaps" back and forth over the medial epicondyle 5
   • Submuscular transposition - In cases of scarring, providing a healthy vascular bed and soft tissue protection 5

Follow-up and Monitoring

• Regular reassessment of pain and function
• Monitoring for medication side effects, especially with tricyclic antidepressants (anticholinergic effects, cardiac toxicity)
• Treatment should be adjusted based on response 1
• For patients treated conservatively, consider surgical referral if symptoms persist beyond 3 months 1

Pitfalls and Caveats

• Differential diagnosis is essential in atypical cases, including C8 radiculopathy, Pancoast tumor, and pressure palsy 5
• Risks of surgical transposition include compromise in blood flow to the nerve and kinking due to insufficient mobilization 5
• Avoid tricyclic antidepressant dosages higher than 100 mg/day due to increased risk of cardiac events 1
• Subluxation of the medial head of the triceps can mimic ulnar nerve subluxation and may require different treatment 6