quesmed orthopaedics

Question 1

A 22 year old woman has an argument with her partner. She grabs a pair of scissors and stabs her partner in the volar aspect of their right distal forearm. Her partner is brought in accident and emergency and is found to be unable to fully extend or flex his 4th and 5th fingers of the right hand. He also complains of numbness in the hand which is particularly pronounced over the 4th and 5th fingers. On further inspection of the wound, intermittent squirts of blood is seen from wound site. Arterial damage is also suspected. Which artery is most likely to have been damaged?

Answer 1

ulnar artery

patient has features of ulnar nerve palsy - ulnar nerve accompanies the ulnar artery on its medial side along medial aspect of the distal forearm

Question 2

what are some of the causes of ulnar nerve injuries

Answer 2

elbow pathology (fractures or dislocations)

impingement in the wrist (Guyon’s Canal)

Question 3

what are the clinical features of ulnar nerve injuries

Answer 3

weakness of the intrinsic muscles of the hand > give rise to ‘claw hand’

finger weakness in both adduction and abduction

sensory loss over the 5th digit

unable to cross their fingers

Question 4

what is this clinical feature

Answer 4

claw hand - ulnar nerve palsy

Question 5

A 15-year old boy presents to the emergency department after a fall while he was skateboarding. He landed awkwardly as he was coming down a slope and hit his right elbow on the pavement. He is complaining of pain in the right elbow and is supporting it with his other hand.

On examination, there is tenderness and swelling over the right humeral shaft. He is unable to flex or extend the right elbow. Extension of the wrist and fingers in the same arm is weak. There is sensory loss over the dorsum of the right hand.

X-ray shows a fracture at the humeral shaft. Which of the following nerves is affected in this patient?

Answer 5

radial nerve

it is vulnerable to injury with fractures of the humeral shaft as it lies in very close proximity to the bone

it descends within the spiral groove on the posterior aspect of the humerus

injury to the radial nerve results in decreased or complete loss to wrist and finger extension as well as sensory loss over the dorm of the right hand