What is the treatment for ulnar nerve compression?

Treatment for Ulnar Nerve Compression (Cubital Tunnel Syndrome)

For primary cubital tunnel syndrome causing ring finger splitting/numbness, simple in situ decompression extending at least 5-6 cm distal to the medial epicondyle is the treatment of choice, which can be performed under local anesthesia using either open or endoscopic technique. 1, 2

Initial Conservative Management

Conservative treatment should be attempted first for early-stage disease before considering surgery: 2

• Avoid external pressure on the elbow and activities that require prolonged elbow flexion beyond 90° 3, 4
• Apply night splints to maintain the elbow in neutral or slight extension during sleep 2
• Position the forearm in supination or neutral when the arm is abducted to decrease pressure on the postcondylar groove 3, 4
• Limit arm abduction to 90° in supine position to prevent further nerve compression 3, 4

Pain Management

• Paracetamol (up to 4g/day) as first-line oral analgesic 3, 4
• Topical NSAIDs for localized pain with fewer systemic side effects 3, 4
• Oral NSAIDs at lowest effective dose for shortest duration if paracetamol inadequate 4
• Range of motion and strengthening exercises with local heat application before exercise 3, 4

Surgical Indications

Surgery is indicated when conservative treatment fails OR when patients present with motor weakness, muscle atrophy, or fixed sensory changes. 2

Primary Surgical Approach: Simple In Situ Decompression

This is the gold standard for primary cubital tunnel syndrome based on randomized controlled trials: 1, 2

• Decompress the entire cubital tunnel including the retrocondylar groove, cubital tunnel retinaculum (Osborne ligament), humeroulnar arcade, and deep flexor/pronator aponeurosis 1, 2
• Extend decompression at least 5-6 cm distal to the medial epicondyle 1, 2
• Can be performed open or endoscopic, both under local anesthesia 1, 2
• Preserves anatomy and vascularization with possibility of rapid postoperative rehabilitation 5

When to Consider Anterior Transposition Instead

Anterior transposition is indicated in specific circumstances: 1, 2, 6

• Painful ulnar nerve subluxation where the nerve "snaps" back and forth over the medial epicondyle 2
• Severe bony or tissue changes of the elbow, especially cubitus valgus deformity 1, 2
• McGowan Grade 3 (severe) symptoms - anterior intramuscular transposition shows best outcomes in this subgroup 5
• Post-traumatic cases with significant elbow deformity 1, 2

Transposition Technique Selection:

• Subcutaneous transposition for uncomplicated subluxation 2
• Submuscular transposition when scarring is present, as it provides healthy vascular bed and soft tissue protection 2

Critical Surgical Pitfalls to Avoid

Insufficient mobilization causes kinking of the nerve and requires revision surgery: 1, 2

• Ensure adequate proximal AND distal mobilization during transposition to prevent kinking 1, 2
• Avoid compromising blood flow to the nerve during transposition 2, 5
• Simple decompression preserves vascularization better than transposition techniques 5

Comparative Outcomes

Patients with simple decompression had the best overall outcomes regardless of preoperative status, while anterior subcutaneous and submuscular transposition had the worst outcomes. 5

However, for McGowan Grade 3 (severe) symptoms specifically, anterior intramuscular transposition showed the best outcomes, followed by simple decompression. 5

All surgical techniques (in situ decompression, transposition, medial epicondylectomy) have shown effectiveness, with comparative studies showing only short-term advantages between techniques but essentially equivocal long-term results. 6

Diagnostic Confirmation

Before proceeding with treatment, confirm diagnosis with: 3, 4

• Electrodiagnostic studies showing the classic "sural sparing pattern" to differentiate from other conditions 3
• Ultrasound with high accuracy (sensitivity 77-79%, specificity 94-98%) for assessing cross-sectional area and nerve thickness 3, 4
• MRI with T2-weighted neurography as reference standard showing high signal intensity and nerve enlargement 3, 4
• Shear-wave elastography with 100% specificity and sensitivity 3, 4

Special Considerations

Rule out double crush syndrome (C8 radiculopathy, Pancoast tumor) in atypical presentations. 1, 2

Chronic untreated compression leads to irreversible atrophy of the first dorsal interosseous muscle and affects quality of life to the point patients cannot perform daily activities requiring fine motor function. 7, 6