Radial Nerve Lesions/Compression

Background

• The most frequent sites of compression are
  • the proximal forearm in the region of the supinator muscles, causing compression of the posterior interosseus nerve
  • a fractured humerus (between the middle and proximal thirds)

Anatomy of the radial nerve

Presentation

• Radial nerve palsy (fractured humerus)
  • Weakness of the wrist and hand extensors, supination.
  • Numbness/paraesthesia over the dorsoradial aspect of the hand and radial 3 digits.
• Radial tunnel syndrome
  • Pain over the anterolateral proximal forearm (over the radial neck- usually >5cm distal to the lateral epicondyle cf lateral epicondylitis), made worse by extension of the elbow and pronation
  • Weakness/numbness are usually late presentations
• Posterior interosseus compression
  • Weakness of the extensors of the wrist/hand
  • Sensation usually preserved

Investigations and Management

• X-ray if radial nerve palsy (particularly with a history of trauma)
• Most diagnoses are clinical and do not require further testing.
• Management is mostly conservative (where surgery for fracture e.g. in open fractures, is not indicated).