What is the management of radial tunnel syndrome?

Radial Tunnel Syndrome: Presentation and Management

Clinical Presentation

Radial tunnel syndrome presents as lateral elbow and proximal forearm pain without motor weakness, distinguishing it from posterior interosseous nerve (PIN) syndrome which causes motor deficits. 1, 2

Key Clinical Features

• Pain location: Lateral elbow extending into the proximal dorsal forearm, often mimicking lateral epicondylitis (tennis elbow) 1, 3
• Pain characteristics: Aching, deep pain that worsens with repetitive forearm rotation and resisted supination 2
• No motor weakness: Critical distinguishing feature from PIN syndrome—patients maintain full motor function 1
• Occupational pattern: Particularly affects patients with repetitive manual tasks and forearm rotation activities 3

Physical Examination Findings

• Tenderness: Point tenderness 3-5 cm distal to the lateral epicondyle over the radial tunnel 2
• Provocative maneuvers: Pain with resisted supination and resisted long finger extension 2
• Rule of Nine test: Pain with resisted forearm supination while elbow extended 2
• Absence of sensory deficits: No numbness or paresthesias, unlike other radial nerve pathologies 1

Management Algorithm

Step 1: Initial Conservative Management (3-6 months)

Conservative treatment should be attempted first, though traditional approaches have historically shown limited success with only 30-33% achieving symptom resolution. 1, 4

Traditional Conservative Options

• Activity modification: Avoid repetitive supination and pronation movements 5
• Splinting: Forearm-based splint to limit supination 5
• NSAIDs: For pain control 5
• Physical therapy: Nerve gliding exercises and ergonomic modifications 5

Emerging Conservative Options with Better Evidence

• Ultrasound-guided corticosteroid injection: Hydrodissection around the posterior interosseous nerve at compression sites shows promising results 1
• Dry needling: Of the affected area demonstrates potential benefit 1

Step 2: Surgical Decompression

Surgical decompression is the standard treatment when conservative management fails, with success rates ranging from 67-92%. 1, 3, 4

Indications for Surgery

• Failure of conservative treatment after 3-6 months 4
• Persistent symptoms interfering with daily activities or work 3
• Clear anatomic compression identified on imaging 2

Surgical Outcomes

• 70% achieve excellent or good results 3
• 13% achieve fair results 3
• 17% have poor outcomes 3
• Success can occur even with prolonged symptom duration (>12 months) 3

Surgical Technique

• Proximal decompression of the radial nerve 3
• Release of the arcade of Frohse (fibrous edge of supinator muscle) 2
• Exploration of all potential compression sites including ECRB, radial recurrent vessels, and distal supinator edge 2

Critical Diagnostic Considerations

Differential Diagnosis

RTS is frequently misdiagnosed as lateral epicondylitis, chronic wrist pain, or tenosynovitis due to overlapping symptoms and lack of reliable objective criteria. 3

• Lateral epicondylitis (tennis elbow): Most common mimicker 3
• PIN syndrome: Distinguished by presence of motor weakness 1
• Cervical radiculopathy: Evaluate neck symptoms and dermatomal patterns 2
• Intersection syndrome: More distal pain location 2

Diagnostic Imaging

• MRI: May identify space-occupying lesions or anatomic variants 2
• Ultrasound: Can visualize nerve compression and guide injections 1
• EMG/NCS: Typically normal in RTS (unlike PIN syndrome), but may help exclude other diagnoses 2

Common Pitfalls to Avoid

• Delaying diagnosis: Always consider RTS in lateral elbow pain unresponsive to tennis elbow treatment 3
• Premature surgery: Ensure adequate trial of conservative management unless clear surgical indication 4
• Overlooking occupational factors: 66% of patients with ongoing medico-legal claims had successful surgical outcomes, suggesting work-related etiology is significant 3
• Expecting immediate results: Symptom resolution may take months even after successful surgery 3

Special Populations

Patients with occupations requiring repetitive manual tasks are at particularly high risk and should receive early ergonomic intervention. 3