This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
All of the following are types of avascular nonunion of fracture except NOT RELATED-OHO 
Select and explain. 
A. Torsion wedge nonunion, B. Oligotrophic nonunion, C. Comminuted nonunion, D. Defect nonunion
B: Oligotrophic nonunion
Answer: B: Oligotrophic nonunion 
Explanation: Definition (FDA panel) of nonunion: It is said to be established when a minimum of 9 months has elapsed since injury and fracture shows no radiologically visible progress suggestive of healing continuously for 3 months.