19th February 2024

A 34-year-old male sustained a left distal humeral fracture following a road traffic accident.

A 34-year-old male sustained a left distal humeral fracture following a road traffic accident. This was managed surgically, and his pain is under control. He reports difficulty in forming a fist when bloods were being taken. He is unable to hold an OK sign with his left hand. Thumb, index finger and third finger flexion power were reduced. Normal sensation was noted over the palmar and dorsal aspect of the hand. 

Which of the following nerves has been affected?