Radial nerve palsy

Question 1

mechanism of injury of radial nerve palsy + at different body level

Answer 1

Acute trauma/compression of radial nerve
- Axilla level e.g. Saturday night palsy, Honeymoon palsy, crutch palsy

• Mid humerus e.g. humeral fracture
• Elbow level e.g. elbow dislocation, upper radius #

Question 2

Innervation of radial nerve

Answer 2

Radial nerve innervate the tricep brachii (extend elbow), brachio-radialis (flex elbow), extensor carpi radialis longus (wrist extension and radial deviation) , and extensor carpi radialis brevis

Posterior interosseous nerve innervate supinator, extensors except ECRL and the radial sensory nerve

Question 3

Clinical appearance of high level (above elbow) and low level (below elbow) of radial nerve palsy

Answer 3

High level of radial nerve palsy:
- unable to extend elbow
- Wrist drop
- Finger MCPJ in flexion (lumbricals pull against paralyzed extensor digitorum)
~~~
Low level of radial nerve palsy:
- Finger MCPJ in flexion
- weak in supination

Question 4

Ax of radial nerve palsy

Answer 4

• Grip Strength Test
• Pin Prick Sensation Test
• Fine Motor Control Test
• Wrist Range of Motion Test

Question 5

Splintage of Radial tunnel syndrome

Answer 5

Radial tunnel syndrome:
Non-op –> long arm splint, elbow flexed, forearm supinated, wrist neutral
Op –> same for 2 weeks, then change to wrist cock-up splint for 2 weeks

Question 6

Splintage of Posterior Interosseous nerve syndrome

Answer 6

elbow flexed, forearm supinated, wrist extension
(avoid prolonged pronation with elbow extension)

Question 7

Problems of radial nerve palsy

Answer 7

Wrist drop
- manipulating objects
- release of objects