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: Unknown
Which is not involved in Ankylosing spondylitis : 
Select and explain. 
A. Knee & Ankle, B. Sacroiliac joint, C. Wrist & elbow, D. Spine
C: Wrist & elbow
Answer: C: Wrist & elbow 
Explanation: Ans. is 'c' ie Wrist & elbow Ankylosing spondylitis also k/a Marie-Strumpell ds is a chronic ds characterized by progressive inflammatory stiffening of the joints with a predilection for the joints of axial skeleton. MC involved joint - Sacro iliac joint* , next is spine Also Remember Sex ratio : M>F (10:1)* Age gp : young (15-30 yr) X-ray appearance Bamboo spine* Squaring of vertebrae Ankylosing spondylitis is a very imp topic and a good look at it will definitely help you.