This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
A 30 Yr old male underwent excision of the right radial head following surgery, the patient has developed inability to move fingers and thumb of the right hand, he did not have any sensory deficit. Which of the following is most likely cause 
Select and explain. 
A. Injury to posterior Interooseus nerve, B. Iatrogenic injury to common extensor origin, C. Injury to anterior Interooseus nerve, D. High radial nerve palsy
A: Injury to posterior Interooseus nerve
Answer: A: Injury to posterior Interooseus nerve 
Explanation: Clinical feaurues of injury to posterior Interosseus nerve : It is prone to be injured in injury and operations of radial Head neck There is no sensory deficit as it is a pure motor nerve Wrist extension is preserved due to spared extensor carpi radialis longus Presents with loss of extension of MP joints Refer Maheshwari 9th ed p 65