Surgery A person is not able to extend his metacarpophalangeal joint. This is due to injury to which nerve? A Ulnar nerve B Radial nerve injury C Median nerve injury D Post. Introsseus nerve injury 💡 Explanation A person is not able to extend his metacarpophalangeal joint. This is due to injury to which nerve? ✓ Correct Answer: D. Post. Introsseus nerve injury