Radial Nerve Injury
Common Injury Mechanisms
Axillary Region Injuries
- Crutch pressing up into armpit (wrong usage)
- Fractures of humeral shaft
- Saturday night palsy: Drunkard falling asleep with one arm over the back of a chair
©Novartis
Fracture of humeral shaft with entrapment of radial nerve in spiral groove
©Novartis
Compression of nerve in axilla or upper arm in patient sleeping with arm over chair back, edge of bed, etc, or by crutch
Spiral Groove Injuries
- Fracture shaft of humerus
- Tourniquet palsy
Forearm Injuries
- Posterior interosseous nerve
- Only finger drop (important to remember)
Clinical Manifestations
Motor Effects: Paralysis of
- Triceps
- Anconeus
- Extensors of the wrist
- Extensors of fingers
- Brachioradialis
- Supinator muscle
Characteristic Deformity
- Wrist and finger drop
Sensory Effects
- Sensory loss over lateral part of the dorsum of the hand (more prominent at anatomical snuffbox)
Level-Specific Findings
Spiral Groove Level
- Motor effects: Paralysis of
- Extensors of the wrist
- Extensors of finger
- (inability to extend the MCP joint)
Forearm Level (Posterior Interosseous Nerve)
- Only finger drop (remember this key distinction)
Treatment and Management
Closed Injuries
- Usually recover (Neuropraxia)
- Splinting
Open Injuries
- Nerve exploration and repair or grafted as soon as possible
- If no recovery:
- Tendon transfers
