What is the treatment for ulnar entrapment (cubital tunnel) syndrome?

Treatment of Ulnar Entrapment (Cubital Tunnel) Syndrome

Conservative treatment for 3-6 months is the first-line approach for ulnar nerve entrapment at the elbow in patients without significant motor weakness or muscle atrophy, and if this fails, simple in-situ decompression is the surgical treatment of choice. 1, 2, 3

Initial Conservative Management (First-Line for 3-6 Months)

Conservative therapy should be attempted initially unless severe motor deficits or muscle atrophy are present at diagnosis 1, 2:

• Positioning modifications: Maintain neutral forearm position when arm is at side to minimize nerve tension 1, 2
• Avoid elbow flexion beyond 90 degrees to reduce compression and subluxation risk 1, 2
• Proper padding application: Use foam or gel pads at the elbow to prevent direct compression, ensuring padding is not too tight to avoid tourniquet effect 1, 2
• NSAIDs: Oral or topical for short-term pain relief (2-4 weeks), though they do not alter long-term outcomes 2
• Cryotherapy: Melting ice water through wet towel for 10-minute periods, repeated multiple times daily 2
• Activity modification: Relative rest to reduce repetitive loading while avoiding complete immobilization 2
• Night splinting: To maintain elbow in extended position during sleep 4, 3

Conservative treatment has been successful for mild cases, with approximately 70% of patients achieving excellent outcomes when appropriately selected 5, 3.

Diagnostic Confirmation

Before proceeding to surgery, confirm the diagnosis:

• Dynamic ultrasound is the preferred initial diagnostic modality to directly visualize ulnar nerve subluxation during elbow flexion 1, 2
• MRI with T2-weighted neurography serves as the reference standard if ultrasound is inconclusive, showing nerve signal intensity and enlargement 6, 1, 2
• Electromyography and nerve conduction studies help confirm diagnosis, particularly in atypical presentations, and differentiate between demyelinating versus axonal injury 1, 2, 3

Surgical Indications

Surgery should be considered when 4, 3:

• Conservative treatment fails after 3-6 months
• Clinical signs of nerve dysfunction or electrophysiologic abnormalities are present
• Motor weakness or muscle atrophy exists at presentation
• Fixed sensory changes are present

Surgical Treatment Options

Simple in-situ decompression is the treatment of choice for primary cubital tunnel syndrome based on randomized controlled studies 3:

• In-situ decompression: Must extend at least 5-6 cm distal to the medial epicondyle 3
• Can be performed open or endoscopically, both under local anesthesia 3
• Results in 70% excellent outcomes with complete symptom resolution 5
• Minimally invasive with mean postoperative disability of 28 days in working patients 5

Alternative surgical techniques for specific scenarios 4, 7, 3:

• Subcutaneous anterior transposition: Indicated when ulnar nerve luxation is painful or "snaps" back and forth over the medial epicondyle 3
• Submuscular anterior transposition: Preferred in cases of scarring, as it provides healthy vascular bed and soft tissue protection 3
• Medial epicondylectomy: Less commonly used, particularly in German-speaking countries 3

The choice between simple decompression and transposition remains controversial, with no single procedure proven optimal for all cases 4, 5, 7. However, simple decompression is recommended as first-line surgical treatment for uncomplicated primary cubital tunnel syndrome and most post-traumatic cases 3.

Critical Pitfalls to Avoid

• Never use padding that is too tight: Creates tourniquet effect and paradoxically increases compression risk 1, 2
• Do not proceed directly to surgery without 3-6 month conservative trial unless significant motor weakness or muscle atrophy is present 1, 2
• Avoid corticosteroid injections as first-line treatment: Unlike tendinopathy, injections are not recommended as primary therapy for nerve compression 2
• Do not allow elbow flexion greater than 90 degrees during conservative period, as this increases ulnar neuropathy risk 1, 2
• Ensure adequate mobilization during transposition: Insufficient proximal or distal mobilization can cause nerve kinking and compromise blood flow, requiring revision surgery 3

Expected Outcomes

With simple decompression 5:

• 70% achieve excellent outcome without residual symptoms
• 12.5% achieve good outcome with slight residual pain and sensory disturbance
• 10% achieve fair outcome with persistent deficits but slow improvement
• 7.5% show no improvement

Sensory disturbances completely disappear in 60% of patients, with improvement in an additional 27.5% 5. Motor recovery occurs completely in 55% of patients with preoperative paresis, with improvement in another 32% 5.