- 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
- 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).