Nerve injuries to the upper limb Flashcards
Will the patient be able to actively extend their elbow if the radial nerve is injured in mid humeral fracture? Explain why?
Yes
The nerve supply to the long and medial head of the triceps is given off before the radial nerve enters the spiral groove
Which muscle might be paralysed if the radial nerve is damaged in a humeral break?
The acroneus - only has a small role in elbow extension so overall movement is not affected
In what position will the patient’s wrist and fingers be when the wrist is pronated, if the radial nerve is damaged in a humeral break? Explain why.
Wrist drop- wrist and fingers flexed
Paralysis of brachioradialis and extensor muscles of wrist and fingers
What is the likely pattern of distribution of sensory impairment if the radial nerve is damaged?
Superficial branch of the radial nerve i.e. posterior of hand over the thumb, index, middle and medial half of the ring finger but NOT the finger tips themselves
How will the hand appear in a supracondular fracture of the humerus that damages the median nerve? Explain why
The hand of benediction
when attempting to make a fist the ring and little finger will flex but, the index and middle finger are paralysed and therefore outstretched
Due to paralysis of the flexor digitorum superficialisand paralysis of the index and middle fingersof theflexor digitorum profundus
What is ape hand?
A deformity due to thenar muscle wasting in a high median nerve lesion. The thumb can be flexed only by flexor pollucis brevis at the MCPJ due to ulnar nerve supply
How does median nerve injury at the wrist present?
Muscles paralysed are LOAF
- Lumbricals of index and middle finger
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis
Atrophy of these muscles referred to as Ape Hand Deformity
What is ulnar claw, in what circumstance would you see this injury?
Ulnar claw is caused by ulnar nerve injury at the wrist. The little and ring fingers are hyperextended at the MCP joint and flexed at the PIP and DIP
How do the injury presentations differ between ulnar nerve injury at the wrist vs in medial epicondylar fracture?
At the wrist → ulnar claw. Ulnar half of flexor digitorum profundus is still intact
High ulnar nerve lesion → ulnar claw is less pronounced as the ulnar half of the flexor digitorum profundus is lost therefore there is no flexion of the DIP in the ring and little finger
What is the difference in injury presentation between low and high ulnar nerve lesions known as?
Ulnar paradox
