This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Anatomy
Loss of flexion in the interphalangeal joint of thumb in supracondylar fracture is due to involvement of which nerve 
Select and explain. 
A. Anterior interosseous, B. Posterior interosseous, C. Median, D. Ulnar
A: Anterior interosseous
Answer: A: Anterior interosseous 
Explanation: Flexion at IP joint of thumbs - by flexor pollicis longus Nerves that may be involved in supracondylar humerus : 1. Median nerve - most common Paial injury occurs usually. i.e. fibers involved in forming AIN branch. 2. Radial nerve - less often 3. Ulnar nerve - least commonly involved. AIN supply: Flexor pollicis longus * Lateral 1/2 of flexor digitorum profundus * Pronator quadratus