This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Orthopaedics
Subluxation of atlanto-occipital joint is seen in all except: 
Select and explain. 
A. Gout, B. Odontoid dysgenesis, C. Rheumatoid ahritis, D. Ankylosing spondylitis
A: Gout
Answer: A: Gout 
Explanation: Gout very rarely causes cranioveebral anomalies CRANIOVEEBRAL (CV) JUNCTION ANOMALIES: Subluxation of BASE OF SKULL + C1 + C2 Causes are: *